The following is information on Eastern Tent Caterpillar, and insect pest you should be watching for in the landscape.
Our cool spring means that larvae are emerging from egg masses now (13-160 [59 peak] GDD ) and 50 migrating to tree branch forks to form tents. Caterpillars lay a trail of webbing down as they make their way to young leaves to feed. Eastern tent caterpillars are black with tan-colored hairs, irregular blue markings, a white stripe with a yellowish-tan stripe on either side down their back. They prefer to feed on wild cherry, but also readily eat crabapple, ornamental apple, plum, peach, and occasionally birch or ash. Caterpillars feed from 2-598 GDD or while Cornus florida is in full bloom before they mature 50 and leave the tree to search for a suitable location to pupate. The adults emerge in two to four weeks, mate, and females lay eggs in gray foam-like masses with about 150 350 eggs in a mass. Eastern tent caterpillars egg masses are usually laid on twigs or small branches and there is only one generation per year. A number of natural enemies such as assassin bugs, parasitoids, and birds help keep the insect under control. Pruning out egg masses and destroying the eggs in the fall or late winter before egg hatch is an effective cultural method to control eastern tent caterpillar. Some compounds used to control eastern tent caterpillar include: insecticidal soap, B. thuringiensis (Dipel), spinosad (Conserve), chlorantraniliprole (Acelepryn), or pyrethroid products such as bifenthrin. Apply when the larvae are small to increase efficacy and cover both the foliage and the tent.
Information from Brian Kunkel, Ornamental IPM Specialist, UD.
Friday, April 17, 2009
Landscape - Scale Insects: Indian Wax Scale
This is the 15th in a series on scale insects in the landscape. This post is on the Indian Wax Scale. Information is from the University of Maryland.
Indian Wax Scale (Ceroplastes ceriferus), Family Coccidae
Plants Damaged: This soft scale feeds on Chinese and Japanese hollies, azaleas, pyracantha, euonymus, boxwood, flowering quince, camellia, pear, azalea, persimmon, plum, barberry, and magnolia.
Damage Symptoms: This scale is large enough that its mere appearance is aesthetically unpleasing. Heavy populations can cause dieback of the infested plant.
Life Cycle: Females overwinter and eggs are laid in May in Maryland. Crawlers are active in early June. When crawlers emerge they will be yellow to pink in color and will excrete white wax that gives the scale a “cameo” appearance.
Monitoring: The adult females are red and covered with bright white gummy wax. Look for the large, very noticeable females overwintering on the stems.
Control: Horticultural oil does not work well on this scale. Distance applied when crawlers are present works well. Imidacloprid can also be applied as a soil drench in April. It takes 30 - 60 days for uptake into the stems of the plant. Soil application of dinotefuran (Safari) is uptaken in 2 – 3 weeks and should give good control.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Indian Wax Scale (Ceroplastes ceriferus), Family Coccidae
Plants Damaged: This soft scale feeds on Chinese and Japanese hollies, azaleas, pyracantha, euonymus, boxwood, flowering quince, camellia, pear, azalea, persimmon, plum, barberry, and magnolia.
Damage Symptoms: This scale is large enough that its mere appearance is aesthetically unpleasing. Heavy populations can cause dieback of the infested plant.
Life Cycle: Females overwinter and eggs are laid in May in Maryland. Crawlers are active in early June. When crawlers emerge they will be yellow to pink in color and will excrete white wax that gives the scale a “cameo” appearance.
Monitoring: The adult females are red and covered with bright white gummy wax. Look for the large, very noticeable females overwintering on the stems.
Control: Horticultural oil does not work well on this scale. Distance applied when crawlers are present works well. Imidacloprid can also be applied as a soil drench in April. It takes 30 - 60 days for uptake into the stems of the plant. Soil application of dinotefuran (Safari) is uptaken in 2 – 3 weeks and should give good control.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Thursday, April 16, 2009
Nursery, Greenhouse, Turf, and Landscape - Soluble Salts
The following is information problems related to high soluble salts in landscapes, greenhouses, nurseries, and turf.
Each year we see plant damage in turf, landscapes, greenhouses, and nurseries due to high levels of soluble salts in soils or media. High soluble salts can come from a number of sources: deicing materials used in the winter; excessive fertilizer, manure, or compost use; “dumping” of fertilizer salts from certain slow release fertilizers; and irrigation water that is high in salts. Excessive soluble salts can result in reduced growth, loss of vigor, root death, yellowing of leaves, wilting, marginal leaf burn, or plant death. This occurs because soils or media with high salt levels make it more difficult for plants to take up water, or if very high will cause loss of water from roots. Foliage exposed to high salt levels will show symptoms similar to leaf scorch. There is also a potential for certain elements to become toxic in high salt conditions: examples would be sodium or ammonium.
A common problem is over application of fertilizers. This can occur with miscalculation of fertilizer rates or dilutions, poorly calibrated or malfunctioning fertilizer applicators or injectors, or excessive overlapping during application. All soluble fertilizer nutrients (nitrate, ammonium, potassium, calcium, magnesium, chloride, sodium, or sulfate ions), contribute to the soluble salt content of the soil or media. However, some soluble fertilizers have greater chance for salt injury than others. Refer to the salt index of a fertilizer to evaluate the potential to cause salt injury. Certain manures and composts can also contain high salt levels. In greenhouses or nurseries, salt levels often build up in media due to inadequate leaching or poor pot drainage. Dumping of salts from coated slow release fertilizers can also occur in greenhouse and nursery production, especially if fertilizer coatings were damaged in handling or by exposure to excess heat.
If you suspect high salts in soil or media, a soluble salt test should be done (the UD soil testing lab and other soils labs can do this test). Soluble salt content is determined with an electrical conductivity meter using a specified dilution of soil or media. An electrical conductivity meter is a useful instrument for growers, turf professionals and landscapers to have on hand for troubleshooting salt related problems.
Gordon Johnson, Extension Horticulture Agent, UD, Kent County
Each year we see plant damage in turf, landscapes, greenhouses, and nurseries due to high levels of soluble salts in soils or media. High soluble salts can come from a number of sources: deicing materials used in the winter; excessive fertilizer, manure, or compost use; “dumping” of fertilizer salts from certain slow release fertilizers; and irrigation water that is high in salts. Excessive soluble salts can result in reduced growth, loss of vigor, root death, yellowing of leaves, wilting, marginal leaf burn, or plant death. This occurs because soils or media with high salt levels make it more difficult for plants to take up water, or if very high will cause loss of water from roots. Foliage exposed to high salt levels will show symptoms similar to leaf scorch. There is also a potential for certain elements to become toxic in high salt conditions: examples would be sodium or ammonium.
A common problem is over application of fertilizers. This can occur with miscalculation of fertilizer rates or dilutions, poorly calibrated or malfunctioning fertilizer applicators or injectors, or excessive overlapping during application. All soluble fertilizer nutrients (nitrate, ammonium, potassium, calcium, magnesium, chloride, sodium, or sulfate ions), contribute to the soluble salt content of the soil or media. However, some soluble fertilizers have greater chance for salt injury than others. Refer to the salt index of a fertilizer to evaluate the potential to cause salt injury. Certain manures and composts can also contain high salt levels. In greenhouses or nurseries, salt levels often build up in media due to inadequate leaching or poor pot drainage. Dumping of salts from coated slow release fertilizers can also occur in greenhouse and nursery production, especially if fertilizer coatings were damaged in handling or by exposure to excess heat.
If you suspect high salts in soil or media, a soluble salt test should be done (the UD soil testing lab and other soils labs can do this test). Soluble salt content is determined with an electrical conductivity meter using a specified dilution of soil or media. An electrical conductivity meter is a useful instrument for growers, turf professionals and landscapers to have on hand for troubleshooting salt related problems.
Gordon Johnson, Extension Horticulture Agent, UD, Kent County
Landscape - Scale Insects: Winged Euonymus Scale
This is the 14th in a series on scale insects in the landscape. This post is on the Winged Euonymus Scale. Information is from the University of Maryland.
Winged Euonymus Scale (Lepidosaphes yanangicola (Kuwana)), Family Diaspididae
Plants Damaged: Mainly found on winged euonymus (Euonymus alatus), but the scale is reported feeding on maples, ash, lilac and willow.
Damage Symptoms: Yellowing of foliage and dieback of branched in heavy infestations. Heavily infested plants have been defoliated during the growing season.
Life cycle: Third instar females overwinter. Eggs are produced from late May to early June and are present through July. Females produce ‘crawler flaps’ (white edge) 2 - 3 weeks before crawlers emerge.
Monitoring: This scale tends to blend in with the corky ridges on the winged euonymus branches making detection more challenging until your eye is trained to pick up the scale covers.
Control: A mixture of 1% horticultural oil and Distance does a great job of controlling this scale. Dinotefuran (Safari) applied as a soil drench also works well.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Winged Euonymus Scale (Lepidosaphes yanangicola (Kuwana)), Family Diaspididae
Plants Damaged: Mainly found on winged euonymus (Euonymus alatus), but the scale is reported feeding on maples, ash, lilac and willow.
Damage Symptoms: Yellowing of foliage and dieback of branched in heavy infestations. Heavily infested plants have been defoliated during the growing season.
Life cycle: Third instar females overwinter. Eggs are produced from late May to early June and are present through July. Females produce ‘crawler flaps’ (white edge) 2 - 3 weeks before crawlers emerge.
Monitoring: This scale tends to blend in with the corky ridges on the winged euonymus branches making detection more challenging until your eye is trained to pick up the scale covers.
Control: A mixture of 1% horticultural oil and Distance does a great job of controlling this scale. Dinotefuran (Safari) applied as a soil drench also works well.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Wednesday, April 15, 2009
Landscape - Scale Insects: Cryptomeria Scale
This is the 13th in a series on scale insects in the landscape. This post is on the Cryptomeria Scale. Information is from the University of Maryland.
Cryptomeria Scale (Aspidiotus cryptomeriae Kuwana), Family Diaspididae
Plants Damaged: This scale is found on many conifer species including fir, Cedrus, Chamaecyparis, rarely this scale is found on Cryptomeria, pine, spruce, Taxus and hemlock.
Damage Symptoms: As the scale draws out sap from the needles it causes a yellowing spotting of the foliage. Heavy infested plants are chlorotic. Dieback occurs when populations are high.
Life Cycle: This scale overwinters as second instar females. Adults occur in spring in March and April. Females lay eggs in June with crawlers appearing in June through early July. There are two generations per year. Adults of the second generation are present in July and crawlers are present in late August through September. Immatures overwinter on the needles.
Monitoring: Look for chlorotic foliage with yellow spotting or banding on the needles. Look for overwintering scale on the needles.
Control: A mixture of 1% horticultural oil and Distance does a great job of controlling this scale. Dinotefuran (Safari) applied as a soil drench also works well.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Cryptomeria Scale (Aspidiotus cryptomeriae Kuwana), Family Diaspididae
Plants Damaged: This scale is found on many conifer species including fir, Cedrus, Chamaecyparis, rarely this scale is found on Cryptomeria, pine, spruce, Taxus and hemlock.
Damage Symptoms: As the scale draws out sap from the needles it causes a yellowing spotting of the foliage. Heavy infested plants are chlorotic. Dieback occurs when populations are high.
Life Cycle: This scale overwinters as second instar females. Adults occur in spring in March and April. Females lay eggs in June with crawlers appearing in June through early July. There are two generations per year. Adults of the second generation are present in July and crawlers are present in late August through September. Immatures overwinter on the needles.
Monitoring: Look for chlorotic foliage with yellow spotting or banding on the needles. Look for overwintering scale on the needles.
Control: A mixture of 1% horticultural oil and Distance does a great job of controlling this scale. Dinotefuran (Safari) applied as a soil drench also works well.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Tuesday, April 14, 2009
Greenhouse - Botrytis
Botrytis is a common problem in crowded greenhouses, especially during cloudy weather when plants are in bloom. The following is more information.
The extended period of cloudy weather has resulted in Botrytis Blight on closely spaced, tender spring annuals and herbs. Growers are all too familiar with the fuzzy grayish-brown spores (Gray Mold) that are easily spread on air currents and by water splash. Sometimes, less obvious symptoms show as tan colored cankers on stems that can cause entire branches of plants to wilt, such as Fuchsia hanging baskets, while the rest of the plant appears healthy. If left alone, more branches wilt one by one. Fuzzy spores will eventually form on stems deep inside the canopy.
Botrytis blight is best managed by combining environmental and cultural controls with chemical controls.
Environmental controls If you see active fungal sporulation, begin by first reducing the humidity in the greenhouse. Heat and vent in the evening (3x) and early in the morning to exhaust the moist, humid air and replace it with cooler, drier air.
Cultural controls Promptly removing severely infected plants, such as tender herbs, helps to reduce the disease pressure. Place severely infected plants that are covered with the grayish spores, in a plastic bag before removing from the greenhouse. This will help reduce potential spread of the easily airborne spores. Keep garbage cans covered so spores are not released into the greenhouse via air currents. Water early in the day, so foliage can dry rapidly. As plants are sold, provide more space to your existing crops to reduce humidity levels within your crops.
When Botrytis blight develops on herbs, cultural and environmental management is especially crucial because many of the fungicides labeled for ornamentals are not labeled for herbs.
Chemical Controls
Apply preventative fungicides before cutting back plants so the fungal spores are not released onto open wounds as workers handle plants. On ornamental crops, a number of fungicides are labeled for use against Botrytis Blight. The following are some of the fungicides listed under Botrytis management in The New England Recommendation Guide:
Azoxystrobin (Heritage), Bacillus subtillis (Rhapsody, Cease), chlorothalonil(Daconil, Echo and others), copper salts (Camelot), copper sulfate pentahydrate (Phyton 27), fenhexamid (Decree), fludioxonil (Medallion), iprodione (Chipco, 26GT and others), mancozeb (Dithane, Protect), polyoxin D zinc salt (Endorse), trifloxystrobin (Compass), and triflumizole (Terraguard). Combination products are also available containing some of these active ingredients.
Growers often rely on fenhexamid (Decree) which is a non-systemic fungicide with both protective and curative activity, chlorothalonil (Daconil) or iprodione (Chipco, 26 GT). Rotate among mode of action groups to delay the buildup of resistant strains. There are reports of widespread resistance to the benzimidazole fungicides (Cleary’s 3336 and Fungo Flo) as well as resistance to iprodione.
From the current issue of the New England Greenhouse Uptdate http://www.negreenhouseupdate.info/greenhouse_update/index.php
The extended period of cloudy weather has resulted in Botrytis Blight on closely spaced, tender spring annuals and herbs. Growers are all too familiar with the fuzzy grayish-brown spores (Gray Mold) that are easily spread on air currents and by water splash. Sometimes, less obvious symptoms show as tan colored cankers on stems that can cause entire branches of plants to wilt, such as Fuchsia hanging baskets, while the rest of the plant appears healthy. If left alone, more branches wilt one by one. Fuzzy spores will eventually form on stems deep inside the canopy.
Botrytis blight is best managed by combining environmental and cultural controls with chemical controls.
Environmental controls If you see active fungal sporulation, begin by first reducing the humidity in the greenhouse. Heat and vent in the evening (3x) and early in the morning to exhaust the moist, humid air and replace it with cooler, drier air.
Cultural controls Promptly removing severely infected plants, such as tender herbs, helps to reduce the disease pressure. Place severely infected plants that are covered with the grayish spores, in a plastic bag before removing from the greenhouse. This will help reduce potential spread of the easily airborne spores. Keep garbage cans covered so spores are not released into the greenhouse via air currents. Water early in the day, so foliage can dry rapidly. As plants are sold, provide more space to your existing crops to reduce humidity levels within your crops.
When Botrytis blight develops on herbs, cultural and environmental management is especially crucial because many of the fungicides labeled for ornamentals are not labeled for herbs.
Chemical Controls
Apply preventative fungicides before cutting back plants so the fungal spores are not released onto open wounds as workers handle plants. On ornamental crops, a number of fungicides are labeled for use against Botrytis Blight. The following are some of the fungicides listed under Botrytis management in The New England Recommendation Guide:
Azoxystrobin (Heritage), Bacillus subtillis (Rhapsody, Cease), chlorothalonil(Daconil, Echo and others), copper salts (Camelot), copper sulfate pentahydrate (Phyton 27), fenhexamid (Decree), fludioxonil (Medallion), iprodione (Chipco, 26GT and others), mancozeb (Dithane, Protect), polyoxin D zinc salt (Endorse), trifloxystrobin (Compass), and triflumizole (Terraguard). Combination products are also available containing some of these active ingredients.
Growers often rely on fenhexamid (Decree) which is a non-systemic fungicide with both protective and curative activity, chlorothalonil (Daconil) or iprodione (Chipco, 26 GT). Rotate among mode of action groups to delay the buildup of resistant strains. There are reports of widespread resistance to the benzimidazole fungicides (Cleary’s 3336 and Fungo Flo) as well as resistance to iprodione.
From the current issue of the New England Greenhouse Uptdate http://www.negreenhouseupdate.info/greenhouse_update/index.php
Landscape - Scale Insects: Calico Scale
This is the 12th in a series on scale insects in the landscape. This post is on the Calico Scale. Information is from the University of Maryland.
Calico Scale (Eulecanium cerasorum), Family Coccidae
Plants Damaged: Calico scale is a general feeder and can be found on many nursery and landscape plants including dogwood, honeylocust, magnolia, maple, sweet gum, tuliptree and ornamental fruit trees.
Damage Symptoms: Calico scale covers the branches and leaves of the host plant and feeds on the phloem tissue. The plant may be covered in sooty mold as a result of the large quantities of honeydew produced by the calico scale. In large numbers, feeding can result in branch dieback.
Identification: This white and dark brown calico scale is about 1/4 inch in diameter and is brightest when it reaches maturity and then darkens. First-instar nymphs start out pinkish and become yellowish as they enlarge. Overwintering Immature females are oval, flattened, and light to dark brown and have a hard waxy coating. Just before egg hatch the covering is white with gray-blue patterns.
Life Cycle: This scale overwinters as second instars and molts and matures to 3rd instars in early spring. The nymphs of this scale will migrate out onto the foliage in June and feed through the summer. In the fall the immatures will migrate back to the twigs where the females overwinter.
Monitoring: Look for copious amounts of honeydew in late May and early June. Look for the oval-shaped, yellow-bodied crawlers in June.
Control: Apply horticultural oil in March to early April to kill overwintering females. When crawlers are out, use 1% horticultural oil or Distance. Another option for controlling soft scale is to use a soil injection or soil drench of a systemic insecticide, such as imidacloprid or dinotefuran. This material takes 30 - 60 days to be taken up by the plant before it begins to control the scale. It is very effective against soft scale insects such as calico scale.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Calico Scale (Eulecanium cerasorum), Family Coccidae
Plants Damaged: Calico scale is a general feeder and can be found on many nursery and landscape plants including dogwood, honeylocust, magnolia, maple, sweet gum, tuliptree and ornamental fruit trees.
Damage Symptoms: Calico scale covers the branches and leaves of the host plant and feeds on the phloem tissue. The plant may be covered in sooty mold as a result of the large quantities of honeydew produced by the calico scale. In large numbers, feeding can result in branch dieback.
Identification: This white and dark brown calico scale is about 1/4 inch in diameter and is brightest when it reaches maturity and then darkens. First-instar nymphs start out pinkish and become yellowish as they enlarge. Overwintering Immature females are oval, flattened, and light to dark brown and have a hard waxy coating. Just before egg hatch the covering is white with gray-blue patterns.
Life Cycle: This scale overwinters as second instars and molts and matures to 3rd instars in early spring. The nymphs of this scale will migrate out onto the foliage in June and feed through the summer. In the fall the immatures will migrate back to the twigs where the females overwinter.
Monitoring: Look for copious amounts of honeydew in late May and early June. Look for the oval-shaped, yellow-bodied crawlers in June.
Control: Apply horticultural oil in March to early April to kill overwintering females. When crawlers are out, use 1% horticultural oil or Distance. Another option for controlling soft scale is to use a soil injection or soil drench of a systemic insecticide, such as imidacloprid or dinotefuran. This material takes 30 - 60 days to be taken up by the plant before it begins to control the scale. It is very effective against soft scale insects such as calico scale.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Monday, April 13, 2009
Landscape - Scale Insects: White Prunicola Scale
This is the eleventh in a series on scale insects in the landscape. This post is on the White Prunicola Scale. Information is from the University of Maryland.
White Prunicola Scale (Pseudaulacaspis prunicola), Family Diaspididae
Plants Damaged: This scale is commonly found on Prunus species but can also be seen on magnolia, ligustrum, rhododendron, forsythia, boxwood, and lilac.
Damage Symptoms: Dieback of twigs and yellowing of foliage
Life Cycle: Crawlers are present in May. A second generation occurs in July and a third in September. Crawlers appear about 2 weeks earlier than white peach scale. Crawlers are out in early May to June. Second generation crawlers are out from mid-July to mid-August. The third generation crawlers are out in September.
Monitoring: Both male and female crawlers are salmon colored.
Control: When crawlers are out, Distance mixed with 1% horticultural oil gives excellent control.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
White Prunicola Scale (Pseudaulacaspis prunicola), Family Diaspididae
Plants Damaged: This scale is commonly found on Prunus species but can also be seen on magnolia, ligustrum, rhododendron, forsythia, boxwood, and lilac.
Damage Symptoms: Dieback of twigs and yellowing of foliage
Life Cycle: Crawlers are present in May. A second generation occurs in July and a third in September. Crawlers appear about 2 weeks earlier than white peach scale. Crawlers are out in early May to June. Second generation crawlers are out from mid-July to mid-August. The third generation crawlers are out in September.
Monitoring: Both male and female crawlers are salmon colored.
Control: When crawlers are out, Distance mixed with 1% horticultural oil gives excellent control.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Sunday, April 12, 2009
Landscape - Rose Rosette Disease
The following is information on Rose Rosette disease which is thought to be a virus transmitted by the eriophyid mite.
Symptoms of rose rosette disease vary, but some of the more recognizable symptoms include rapid elongation of new shoots and witches' broom on small branches. Leaves are small, distorted, and may have a conspicuous red pigmentation. The red pigmentation is not a consistent symptom. Canes can develop excessive growth of unusually soft and pliable red or green thorns which may stiffen later. This excessive thorniness on the stems is diagnostic for rose rosette disease. Flowers may be distorted with fewer petals than normal, and flower color may be abnormal. Diseased plants may not exhibit all of these symptoms, especially in the early stages of the disease, so diagnosis can be difficult. The red pigmentation may be subtle and hard to distinguish from the normal reddish tinge of new leaves in spring. Monitor roses closely for symptoms to catch this disease as early as possible to help prevent its spread to nearby plants.
Control: Once a plant is infected there is no cure. The plant will die over the next 2 – 4 years. Plants that are showing all of the symptoms should be destroyed immediately. Some people try to control the eriophyid mite that spreads the disease. This involves applying Avid to the foliage every two weeks from May through October. This is obviously a lot of spraying. Forbid does have eriophyid mites on the label. It should provide control for at least 2- 3 weeks. You might be able to extend the spray intervals.
Rose rosette disease symptoms on leaves. Photo by James W. Amrine Jr., West Virginia University, Bugwood.org
Information from the April 10, 2009 edition of the TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers from the University of Maryland Cooperative Extension.
Symptoms of rose rosette disease vary, but some of the more recognizable symptoms include rapid elongation of new shoots and witches' broom on small branches. Leaves are small, distorted, and may have a conspicuous red pigmentation. The red pigmentation is not a consistent symptom. Canes can develop excessive growth of unusually soft and pliable red or green thorns which may stiffen later. This excessive thorniness on the stems is diagnostic for rose rosette disease. Flowers may be distorted with fewer petals than normal, and flower color may be abnormal. Diseased plants may not exhibit all of these symptoms, especially in the early stages of the disease, so diagnosis can be difficult. The red pigmentation may be subtle and hard to distinguish from the normal reddish tinge of new leaves in spring. Monitor roses closely for symptoms to catch this disease as early as possible to help prevent its spread to nearby plants.
Control: Once a plant is infected there is no cure. The plant will die over the next 2 – 4 years. Plants that are showing all of the symptoms should be destroyed immediately. Some people try to control the eriophyid mite that spreads the disease. This involves applying Avid to the foliage every two weeks from May through October. This is obviously a lot of spraying. Forbid does have eriophyid mites on the label. It should provide control for at least 2- 3 weeks. You might be able to extend the spray intervals.
Rose rosette disease symptoms on leaves. Photo by James W. Amrine Jr., West Virginia University, Bugwood.orgInformation from the April 10, 2009 edition of the TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers from the University of Maryland Cooperative Extension.
Landscape - Scale Insects: San Jose Scale
This is the tenth in a series on scale insects in the landscape. This post is on the San Jose Scale. Information is from the University of Maryland.
San Jose Scale (Quadraspidiotus perniciosus), Family Diaspididae
Plants Damaged: This armored scale can be found on apples, crabapples, and ornamental and edible plums, peaches and pears. It will also feed on cherry laurel, cotoneaster, pyracantha, rose, and other plants in the rose family.
Damage Symptoms: It feeds on the twigs and small branches and weakens the plant.
Yellowing of foliage and dieback of branches
Life Cycle: San Jose scale has three generations per year. The 3rd generation crawlers are still active in October. On apples the crawlers will move out onto the fruit in the first crawler emergence in May and during the second crawler emergence in July. The 3rd generation crawlers tend to be found on the twigs and branches and less on the fruit. On apples you will see round red circles on the fruit.
Monitoring: The female covers are light brown and round with a raised center. Examine
branches and twigs for the presence of overwintering female covers. Use a hand lens to examine foliage for presence of bright yellow crawlers which emerge in May and June.
Control: Target the crawler stage for the best control. Apply Distance and 1 % horticultural oil.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
San Jose Scale (Quadraspidiotus perniciosus), Family Diaspididae
Plants Damaged: This armored scale can be found on apples, crabapples, and ornamental and edible plums, peaches and pears. It will also feed on cherry laurel, cotoneaster, pyracantha, rose, and other plants in the rose family.
Damage Symptoms: It feeds on the twigs and small branches and weakens the plant.
Yellowing of foliage and dieback of branches
Life Cycle: San Jose scale has three generations per year. The 3rd generation crawlers are still active in October. On apples the crawlers will move out onto the fruit in the first crawler emergence in May and during the second crawler emergence in July. The 3rd generation crawlers tend to be found on the twigs and branches and less on the fruit. On apples you will see round red circles on the fruit.
Monitoring: The female covers are light brown and round with a raised center. Examine
branches and twigs for the presence of overwintering female covers. Use a hand lens to examine foliage for presence of bright yellow crawlers which emerge in May and June.
Control: Target the crawler stage for the best control. Apply Distance and 1 % horticultural oil.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Saturday, April 11, 2009
Greenhouse - Geranium Pointers and Troubleshooting
The following are some pointers and troubleshooting hints for geranium production from the University of Maryland.
Sudden pH Drops:
Your geraniums may be humming along but make sure you are maintaining a correct pH level. If you let the pH fall off the plants will go downhill rapidly. Check your pH level at least weekly to detect any downward turns. There is a condition called sudden pH decline (SPD) where geranium crops growing at the optimum pH rapidly (1- 2 weeks) have the substrate pH shift downward 1 to 2 units. Taylor et al., 2008, reports that this occurs when phosphorus is deficient in the substrate and high temperatures cause stress of the geranium crops.
Proper pH:
The optimal pH varies by the type of geranium and root medium used. For zonal geraniums, the range for a soilless root medium is 5.8 to 6.2 and for a soil-based medium is 6.0 to 6.5. The optimal range is up to 0.3 units lower for ivy and regal geraniums (5.5 - 6.2). If modifications are required, the pH can be lowered with an acid-based fertilizer or acid injection. The pH can be increased with dolomitic limestone or hydrated lime.
Electrical Conductivity (EC):
The optimal EC range is 1.5 to 2.5 mS/cm for zonal and regal geraniums. Slightly lower levels are required by ivy geraniums, usually 1.0 – 2.0 mS/cm. Aphids on Geraniums: Monitor ivy geraniums for melon aphids and green peach aphids. We are seeing populations increasing in some greenhouses this week.
Control: Imidacloprid (Marathon), dinotefuran (Safari), Acetamiprid (TriStar), Endeavor, Aria, insecticidal soaps.
Diseases to watch out for on Geraniums:
One disease to watch out for on geraniums is bacterial leaf spot. This disease is caused by the bacterium Xanthomonas pelargonii and is especially prevalent in warm, wet weather where plants are grown in crowded conditions. Disease symptoms include small (pinhead size), circular or irregular, brown, sunken spots on older or lower leaves. Large numbers of spots will occur on a single leaf, these will coalesce and can kill a large portion of the leaf which will then drop off. As the disease moves through the plant, the lower leaves wilt and yellow. In severe cases, the stem will possess black stem cankers killing the upper portion of the stem. Leaves infected with bacterial leaf spot should be removed as soon as it is noticed. Severely infected plants should be removed.
Monitor for Botrytis leaf spot or blossom blight. It is caused by Botrytis cinerea. Botrytis is favored under cool, moist conditions or where plants are watered frequently. Leaves develop zonate, brown leaf lesions which develop a grayish brown mass of fungal spores. The lower leaves will yellow and rot. Flowers may also become infected. They show discolored petals which wilt and fall. Remove affected leaves and flowers. Maintain good air circulation in the greenhouse.
Reprinted from the April 3, 2009 edition of the Greenhouse TPM/IPM Bi-Weekly Report from the University of Maryland Cooperative Extension, Central Maryland Research and Education Center http://www.ipmnet.umd.edu/09Apr03G.pdf
Sudden pH Drops:
Your geraniums may be humming along but make sure you are maintaining a correct pH level. If you let the pH fall off the plants will go downhill rapidly. Check your pH level at least weekly to detect any downward turns. There is a condition called sudden pH decline (SPD) where geranium crops growing at the optimum pH rapidly (1- 2 weeks) have the substrate pH shift downward 1 to 2 units. Taylor et al., 2008, reports that this occurs when phosphorus is deficient in the substrate and high temperatures cause stress of the geranium crops.
Proper pH:
The optimal pH varies by the type of geranium and root medium used. For zonal geraniums, the range for a soilless root medium is 5.8 to 6.2 and for a soil-based medium is 6.0 to 6.5. The optimal range is up to 0.3 units lower for ivy and regal geraniums (5.5 - 6.2). If modifications are required, the pH can be lowered with an acid-based fertilizer or acid injection. The pH can be increased with dolomitic limestone or hydrated lime.
Electrical Conductivity (EC):
The optimal EC range is 1.5 to 2.5 mS/cm for zonal and regal geraniums. Slightly lower levels are required by ivy geraniums, usually 1.0 – 2.0 mS/cm. Aphids on Geraniums: Monitor ivy geraniums for melon aphids and green peach aphids. We are seeing populations increasing in some greenhouses this week.
Control: Imidacloprid (Marathon), dinotefuran (Safari), Acetamiprid (TriStar), Endeavor, Aria, insecticidal soaps.
Diseases to watch out for on Geraniums:
One disease to watch out for on geraniums is bacterial leaf spot. This disease is caused by the bacterium Xanthomonas pelargonii and is especially prevalent in warm, wet weather where plants are grown in crowded conditions. Disease symptoms include small (pinhead size), circular or irregular, brown, sunken spots on older or lower leaves. Large numbers of spots will occur on a single leaf, these will coalesce and can kill a large portion of the leaf which will then drop off. As the disease moves through the plant, the lower leaves wilt and yellow. In severe cases, the stem will possess black stem cankers killing the upper portion of the stem. Leaves infected with bacterial leaf spot should be removed as soon as it is noticed. Severely infected plants should be removed.
Monitor for Botrytis leaf spot or blossom blight. It is caused by Botrytis cinerea. Botrytis is favored under cool, moist conditions or where plants are watered frequently. Leaves develop zonate, brown leaf lesions which develop a grayish brown mass of fungal spores. The lower leaves will yellow and rot. Flowers may also become infected. They show discolored petals which wilt and fall. Remove affected leaves and flowers. Maintain good air circulation in the greenhouse.
Reprinted from the April 3, 2009 edition of the Greenhouse TPM/IPM Bi-Weekly Report from the University of Maryland Cooperative Extension, Central Maryland Research and Education Center http://www.ipmnet.umd.edu/09Apr03G.pdf
Landscape - Scale Insects: Pine Needle Scale
This is the ninth in a series on scale insects in the landscape. This post is on the Pine Needle Scale. Information is from the University of Maryland.
Pine Needle Scale (Chionaspis pinifoliae (Fitch)), Family Diaspididae
Plants Damaged: Pine is the main host, but it has been observed on Abies (Spruce), Pseudotsuga, and Tsuga (hemlock).
Damage Symptoms: Yellowing of foliage and dieback of branches. This scale often exists in low levels on white pines but rarely reaches damaging levels.
Life Cycle: This scale overwinters as females and eggs. Crawlers are present in May. The secondgeneration occurs in mid summer with crawlers present from July through August.
Monitoring: When Sargent crabapple is in full bloom we can expect to see crawlers on pine needle scale. The reddish nymphs hatch in May and there is a second generation in July.
Control: Horticultural oil or Distance at crawler emergence. Dinotefuran (Safari) is reported to control this scale.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Pine Needle Scale (Chionaspis pinifoliae (Fitch)), Family Diaspididae
Plants Damaged: Pine is the main host, but it has been observed on Abies (Spruce), Pseudotsuga, and Tsuga (hemlock).
Damage Symptoms: Yellowing of foliage and dieback of branches. This scale often exists in low levels on white pines but rarely reaches damaging levels.
Life Cycle: This scale overwinters as females and eggs. Crawlers are present in May. The secondgeneration occurs in mid summer with crawlers present from July through August.
Monitoring: When Sargent crabapple is in full bloom we can expect to see crawlers on pine needle scale. The reddish nymphs hatch in May and there is a second generation in July.
Control: Horticultural oil or Distance at crawler emergence. Dinotefuran (Safari) is reported to control this scale.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Friday, April 10, 2009
Turf - Fertilization in the Spring
The following is information on spring fertilization in turf from Virginia Tech.
There is no better money spent than to have a soil test done on the turf areas at least every third year. A soil test is the only way to determine if the soil needs lime, phosphorus (P) or potassium (K). Apply nutrients as recommended by a soil test and you’ll be taking a huge first step towards protecting water quality.
Nitrogen gets the most attention. The one nutrient that won’t be analyzed in a soil test is nitrogen (N). That is surprising since N is the focal point of turf fertility programs. The reason is that N levels change rapidly in a soil and test results usually have little meaning by the time you receive the report. The test results will provide recommendations on appropriate N application levels suitable for the grass and location.
Spring is one of the trickiest times to optimize N fertility. Cool-season grasses such as tall fescue or Kentucky bluegrass have their most significant period of root development in the spring, so some N is beneficial. High rates of N promote a lush, dark green lawn, but there is too much emphasis on shoot growth rather than roots, and this often leads to serious problems with disease, insects, or drought later in the year.
Warm-season grasses like bermudagrass or zoysiagrass don’t initiate much root growth until after shoot greening is complete, so the ideal scenario is to wait at least until 50-75% green-up before applying N. Excessive spring N fertilization that promotes a lot of warm season grass shoot growth can be disastrous to the turf if there is a late freeze.
Choosing a N source.
When selecting a fertilizer for the spring take a close look at the fertilizer label. It tells exactly what nutrients are contained in the product on a percent by weight basis and indicates the N release rate. Most garden fertilizers typically contain large amounts each of N, P, and K (e.g. 10-10-10, 19-19-19, etc.). The N in these sources is almost always entirely water soluble (WSN) and provides quick plant response. Specialty turf fertilizers contain high N percentages and lower levels of P and K (e.g. 29-3-7). This doesn’t mean the P and K aren’t needed by the plant, but history and experience show that repeated applications of garden fertilizers over the years results in soils testing high to very high in P and K. Unnecessary applications of P and K over time can ultimately result in water quality concerns (from excessive P) and nutrient imbalance (likely from excessive K).
Specialty turf fertilizers also often contain different forms of N that provide varying N-release rates and the label indicates the percentages of both WSN and water insoluble N (WIN) making up the total % N in the product. Organic fertilizers are usually very low N analyses (6-10% by weight) and are mostly WIN (often up to 85% of the total N). The higher the % WIN the more slowly available the N is to the plant by way of chemical and microbial reactions in the soil. Any source containing 50% or more WIN can be safely applied at higher application rates with minimal concern for nutrient leaching. However, understand this -- the plant does not care what the source is, only that its needs are met with appropriate application levels and timing.
N rates
The level of N depends on the fertilizer source, the grass, and area of the state. However, here are some basic guidelines. Fertilizer sources that contain more than 50% WIN can be applied up to 1.5 lbs N/1000 sq ft; those that are predominantly WSN should be applied at no more than 1 lb N/1000 sq ft. Recommended N levels from now through the end of May on cool-season grasses should not exceed a total of 1.5 lbs/1000 sq ft for Kentucky bluegrass, tall fescue, or perennial ryegrass, and no more than 1 lb for fine-leaf fescue. The rest of the recommended seasonal N fertility shouldn’t be applied until this fall. For warm-season grasses, allow some greening to occur before applying N, and resist the temptation to initiate standard N fertility programs of up to 1 lb N/1000 sq ft until the average last frost date has passed. Finally, consider that zoysiagrass performs best at 1-2 lbs N/1000 sq ft total per year, whereas bermudagrass can safely receive up to 3-4 lbs total.
Adapted from "Spring Lawn Fertilization—Getting it Right!" by Mike Goatley, Extension Turf Specialist/Associate Professor Crop & Soil Environmental Sciences, Virginia Tech. Go to http://www.weblogs.cals.vt.edu/lawn_garden/ for the podcast.
There is no better money spent than to have a soil test done on the turf areas at least every third year. A soil test is the only way to determine if the soil needs lime, phosphorus (P) or potassium (K). Apply nutrients as recommended by a soil test and you’ll be taking a huge first step towards protecting water quality.
Nitrogen gets the most attention. The one nutrient that won’t be analyzed in a soil test is nitrogen (N). That is surprising since N is the focal point of turf fertility programs. The reason is that N levels change rapidly in a soil and test results usually have little meaning by the time you receive the report. The test results will provide recommendations on appropriate N application levels suitable for the grass and location.
Spring is one of the trickiest times to optimize N fertility. Cool-season grasses such as tall fescue or Kentucky bluegrass have their most significant period of root development in the spring, so some N is beneficial. High rates of N promote a lush, dark green lawn, but there is too much emphasis on shoot growth rather than roots, and this often leads to serious problems with disease, insects, or drought later in the year.
Warm-season grasses like bermudagrass or zoysiagrass don’t initiate much root growth until after shoot greening is complete, so the ideal scenario is to wait at least until 50-75% green-up before applying N. Excessive spring N fertilization that promotes a lot of warm season grass shoot growth can be disastrous to the turf if there is a late freeze.
Choosing a N source.
When selecting a fertilizer for the spring take a close look at the fertilizer label. It tells exactly what nutrients are contained in the product on a percent by weight basis and indicates the N release rate. Most garden fertilizers typically contain large amounts each of N, P, and K (e.g. 10-10-10, 19-19-19, etc.). The N in these sources is almost always entirely water soluble (WSN) and provides quick plant response. Specialty turf fertilizers contain high N percentages and lower levels of P and K (e.g. 29-3-7). This doesn’t mean the P and K aren’t needed by the plant, but history and experience show that repeated applications of garden fertilizers over the years results in soils testing high to very high in P and K. Unnecessary applications of P and K over time can ultimately result in water quality concerns (from excessive P) and nutrient imbalance (likely from excessive K).
Specialty turf fertilizers also often contain different forms of N that provide varying N-release rates and the label indicates the percentages of both WSN and water insoluble N (WIN) making up the total % N in the product. Organic fertilizers are usually very low N analyses (6-10% by weight) and are mostly WIN (often up to 85% of the total N). The higher the % WIN the more slowly available the N is to the plant by way of chemical and microbial reactions in the soil. Any source containing 50% or more WIN can be safely applied at higher application rates with minimal concern for nutrient leaching. However, understand this -- the plant does not care what the source is, only that its needs are met with appropriate application levels and timing.
N rates
The level of N depends on the fertilizer source, the grass, and area of the state. However, here are some basic guidelines. Fertilizer sources that contain more than 50% WIN can be applied up to 1.5 lbs N/1000 sq ft; those that are predominantly WSN should be applied at no more than 1 lb N/1000 sq ft. Recommended N levels from now through the end of May on cool-season grasses should not exceed a total of 1.5 lbs/1000 sq ft for Kentucky bluegrass, tall fescue, or perennial ryegrass, and no more than 1 lb for fine-leaf fescue. The rest of the recommended seasonal N fertility shouldn’t be applied until this fall. For warm-season grasses, allow some greening to occur before applying N, and resist the temptation to initiate standard N fertility programs of up to 1 lb N/1000 sq ft until the average last frost date has passed. Finally, consider that zoysiagrass performs best at 1-2 lbs N/1000 sq ft total per year, whereas bermudagrass can safely receive up to 3-4 lbs total.
Adapted from "Spring Lawn Fertilization—Getting it Right!" by Mike Goatley, Extension Turf Specialist/Associate Professor Crop & Soil Environmental Sciences, Virginia Tech. Go to http://www.weblogs.cals.vt.edu/lawn_garden/ for the podcast.
Landscape - Scale Insects: Oystershell Scale
This is the eighth in a series on scale insects in the landscape. This post is on the Oystershell Scale. Information is from the University of Maryland.
Oystershell Scale (Lepidosaphes ulmi (Linnaeus)), Family Diaspididae
Plants Damaged: This scale is a general feeder (polyphagous) and is reported on 85 host plants in 33 families. We have observed it commonly on Acer (maples), Amelanchier (serviceberry), Cercis (redbud), Crataegus (hawthorn), Quercus (oak), and Prunus spp., but is found on many additional species.
Damage Symptoms: Yellowing of foliage and dieback of branches.
Life Cycle: There are univoltine and bivoltine forms found in Maryland. Bivoltine forms have crawlers present in April. Crawlers of the univoltine form are present from May through June.
Monitoring: The adult females of this armored scale look like elongated oysters.
Control: Horticultural oil or Distance at crawler emergence.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Oystershell Scale (Lepidosaphes ulmi (Linnaeus)), Family Diaspididae
Plants Damaged: This scale is a general feeder (polyphagous) and is reported on 85 host plants in 33 families. We have observed it commonly on Acer (maples), Amelanchier (serviceberry), Cercis (redbud), Crataegus (hawthorn), Quercus (oak), and Prunus spp., but is found on many additional species.
Damage Symptoms: Yellowing of foliage and dieback of branches.
Life Cycle: There are univoltine and bivoltine forms found in Maryland. Bivoltine forms have crawlers present in April. Crawlers of the univoltine form are present from May through June.
Monitoring: The adult females of this armored scale look like elongated oysters.
Control: Horticultural oil or Distance at crawler emergence.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Thursday, April 9, 2009
Landscape and Nursery - Plants for Delaware Landscapes Featured at the 2009 UDBG Spring Plant Sale #18
This year, the University of Delaware Botanic Garden spring benefit plant sale features those plants that add to the biodiversity of the landscape and offer food and habitat for wildlife, especially insects and the birds that eat them. Many native plants are featured. This is the 18th in a series on plants being offered at the UDBG spring plant sale that are recommended for Delaware landscapes.
Elderberry. Photo by Richard Webb, Self-employed horticulurist, Bugwood.org.
Carolina Rose. Photo by John D. Byrd, Mississippi State University, Bugwood.org.
Lowbush Blueberry. Photo by R.A. Howard. ©Smithsonian Institution. Courtesy of Smithsonian Institution, Richard A. Howard Photograph Collection. United States, ME.
For more information on the 2009 UDBG Spring Plant Sale go to http://ag.udel.edu/udbg/events/annualsale.html
Elderberry. Photo by Richard Webb, Self-employed horticulurist, Bugwood.org.
Carolina Rose. Photo by John D. Byrd, Mississippi State University, Bugwood.org.
Lowbush Blueberry. Photo by R.A. Howard. ©Smithsonian Institution. Courtesy of Smithsonian Institution, Richard A. Howard Photograph Collection. United States, ME. 
For more information on the 2009 UDBG Spring Plant Sale go to http://ag.udel.edu/udbg/events/annualsale.html
Landscape - Scale Insects: Minute Cypress Scale
This is the seventh in a series on scale insects in the landscape. This post is on the Minute Cypress Scale. Information is from the University of Maryland.
Minute Cypress Scale (Carulaspis minima), Family Diaspididae
Plants Damaged: Arborvitae, Chamaecyparis, Cryptomeria, junipers, spruce.
Damage Symptoms: Yellowing of foliage and dieback.
Life Cycle: One generation per year. Fertilized females overwinter and eggs hatch in May andvcrawlers are present from May through early June. Adult males and females are present in early July.
Monitoring: The scale are usually found on the leaf scales of small branches where they feed on the sap of the host plant. Minute cypress scale looks very similar to the Juniper scale, but the crawler period is two weeks later than Juniper scale.
Control: Horticultural oil applied at a 2- 4% rate can be applied in March. Apply Distance and 1% oil when crawlers emerge.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Minute Cypress Scale (Carulaspis minima), Family Diaspididae
Plants Damaged: Arborvitae, Chamaecyparis, Cryptomeria, junipers, spruce.
Damage Symptoms: Yellowing of foliage and dieback.
Life Cycle: One generation per year. Fertilized females overwinter and eggs hatch in May andvcrawlers are present from May through early June. Adult males and females are present in early July.
Monitoring: The scale are usually found on the leaf scales of small branches where they feed on the sap of the host plant. Minute cypress scale looks very similar to the Juniper scale, but the crawler period is two weeks later than Juniper scale.
Control: Horticultural oil applied at a 2- 4% rate can be applied in March. Apply Distance and 1% oil when crawlers emerge.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Wednesday, April 8, 2009
Landscape and Nursery - Plants for Delaware Landscapes Featured at the 2009 UDBG Spring Plant Sale #17
This year, the University of Delaware Botanic Garden spring benefit plant sale features those plants that add to the biodiversity of the landscape and offer food and habitat for wildlife, especially insects and the birds that eat them. Many native plants are featured. This is the 17th in a series on plants being offered at the UDBG spring plant sale that are recommended for Delaware landscapes.
Flameleaf Sumac. Photo by Chris Evans, River to River CWMA, Bugwood.org
‘Gro-Lo’ Fragrant Sumac. Photo from Oregon State University.
Staghorn Sumac. Photo from the Ohio State Archive, The Ohio State University, Bugwood.org
For more information on the 2009 UDBG Spring Plant Sale go to http://ag.udel.edu/udbg/events/annualsale.html
Flameleaf Sumac. Photo by Chris Evans, River to River CWMA, Bugwood.org
‘Gro-Lo’ Fragrant Sumac. Photo from Oregon State University.
Staghorn Sumac. Photo from the Ohio State Archive, The Ohio State University, Bugwood.orgFor more information on the 2009 UDBG Spring Plant Sale go to http://ag.udel.edu/udbg/events/annualsale.html
Landscape - Scale Insects: Fletcher Scale
This is the sixth in a series on scale insects in the landscape. This post is on the Fletcher Scale. Information is from the University of Maryland.
Fletcher Scale (Parthenolecanium fletcheri (Cockerell)), Family Coccidae
Plants Damaged: Arborvitae (Thuja species), and yews (Taxus) are the two plants this soft scale is commonly found on in Maryland. It has been reported on pachysandra and juniper.
Damage Symptoms: Besides causing yellowing of foliage this scale will produce large amounts of honeydew in spring on which sooty mold grows.
Life Cycle: This scale overwinters as 2nd instar females that mature in May. The overwintering females are oval shaped and flattened in profile. In May the females will swell and become distended. The eggs will hatch into crawlers sometime in June- about the time when catalpa trees bloom.
Monitoring: Examine stems of arborvitae and yews in winter looking for the oval shaped overwintering females. In May and June, look for honeydew and sooty mold.
Control: Distance applied when crawlers appear or a soil injection of imidacloprid (Merit) or dinotefuran (Safari).
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Fletcher Scale (Parthenolecanium fletcheri (Cockerell)), Family Coccidae
Plants Damaged: Arborvitae (Thuja species), and yews (Taxus) are the two plants this soft scale is commonly found on in Maryland. It has been reported on pachysandra and juniper.
Damage Symptoms: Besides causing yellowing of foliage this scale will produce large amounts of honeydew in spring on which sooty mold grows.
Life Cycle: This scale overwinters as 2nd instar females that mature in May. The overwintering females are oval shaped and flattened in profile. In May the females will swell and become distended. The eggs will hatch into crawlers sometime in June- about the time when catalpa trees bloom.
Monitoring: Examine stems of arborvitae and yews in winter looking for the oval shaped overwintering females. In May and June, look for honeydew and sooty mold.
Control: Distance applied when crawlers appear or a soil injection of imidacloprid (Merit) or dinotefuran (Safari).
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Tuesday, April 7, 2009
Turf and Landscape - Know Your Soluble Fertilizers 5
This is the fifth in a series on soluble fertilizers for use in turf and landscapes. This post is on ammonium phosphates, phosphorus fertilizers that also contain nitrogen.
Monoammonium Phosphate is gray granular material containing a range of N and P2O5 levels, from 11-48-0 to 13-54-0. The most typical analysis is an 11-48-0. This material has very good physical properties and a salt index of 0.49. The phosphate portion of this product is almost 100% water soluble. Because of its ammoniacal N content, this product acidifies the soil upon nitrification. This material is produced in small granular form and can be used as a P source in turf and landscape fertilizers.
Diammonium Phosphate is a gray granular material whose most typical analysis is an 18-46-0. The P in this material is almost 100% water soluble and its salt index is 0.64. This material is almost as acidifying as ammonium sulfate. It is used in general fertilizer blends for turf and landscapes.
Adapted from "Selected Fertilizers Used in Turfgrass Fertilization" by J.B. Sartain & J.K. Kruse, University of Florida Cooperative Extension.
Monoammonium Phosphate is gray granular material containing a range of N and P2O5 levels, from 11-48-0 to 13-54-0. The most typical analysis is an 11-48-0. This material has very good physical properties and a salt index of 0.49. The phosphate portion of this product is almost 100% water soluble. Because of its ammoniacal N content, this product acidifies the soil upon nitrification. This material is produced in small granular form and can be used as a P source in turf and landscape fertilizers.
Diammonium Phosphate is a gray granular material whose most typical analysis is an 18-46-0. The P in this material is almost 100% water soluble and its salt index is 0.64. This material is almost as acidifying as ammonium sulfate. It is used in general fertilizer blends for turf and landscapes.
Adapted from "Selected Fertilizers Used in Turfgrass Fertilization" by J.B. Sartain & J.K. Kruse, University of Florida Cooperative Extension.
Landscape - Scale Insects: Japanese Maple Scale
This is the fifth in a series on scale insects in the landscape. This post is on the Japanese Maple Scale. Information is from the University of Maryland.
Japanese Maple Scale (Lopholeucaspis japonica (Cockerell)), Family Diaspididae
Plants Damaged: Japanese maple scale is showing up in more and more landscapes and nurseries lately. Look for this scale on Japanese maple, American red maple, dogwood, zelkova, lilac, yellowwood, pyracantha, privet, holly, euonymus, redbud, stewartia, cherry, magnolia, Itea, and styrax.
Damage Symptoms: This armored scale feeds directly on plant cells, not in the phloem tissue like soft scale insects. Heavy populations cause a slow decline of the tree. If high populations have resulted in dead branches on trees, prune these out before crawler hatch to reduce the number of scales potentially moving onto other branches and trees.
Life Cycle: The life cycle is poorly understood. The male and females overwinters as immatures and mature in early spring. There are two generations per year. The 2 generations overlap and crawlers are present from May through October.
Monitoring: Look for the white to gray, narrow oyster shell shaped female covers on twigs and main branches. Use a hand lens to look for the light purple crawlers. They should be out in late May or early June. Activity peaks in June to early July, and then we have a second crawler period in late July to mid September
Control: Applications of 1% horticultural oil and Distance should be made when crawlers are detected. This should have about 2 - 3 week residual activity. At that time monitor your plants again to see if crawlers are still active. The twice-stabbed lady bird beetle provides some biological control of this scale.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Japanese Maple Scale (Lopholeucaspis japonica (Cockerell)), Family Diaspididae
Plants Damaged: Japanese maple scale is showing up in more and more landscapes and nurseries lately. Look for this scale on Japanese maple, American red maple, dogwood, zelkova, lilac, yellowwood, pyracantha, privet, holly, euonymus, redbud, stewartia, cherry, magnolia, Itea, and styrax.
Damage Symptoms: This armored scale feeds directly on plant cells, not in the phloem tissue like soft scale insects. Heavy populations cause a slow decline of the tree. If high populations have resulted in dead branches on trees, prune these out before crawler hatch to reduce the number of scales potentially moving onto other branches and trees.
Life Cycle: The life cycle is poorly understood. The male and females overwinters as immatures and mature in early spring. There are two generations per year. The 2 generations overlap and crawlers are present from May through October.
Monitoring: Look for the white to gray, narrow oyster shell shaped female covers on twigs and main branches. Use a hand lens to look for the light purple crawlers. They should be out in late May or early June. Activity peaks in June to early July, and then we have a second crawler period in late July to mid September
Control: Applications of 1% horticultural oil and Distance should be made when crawlers are detected. This should have about 2 - 3 week residual activity. At that time monitor your plants again to see if crawlers are still active. The twice-stabbed lady bird beetle provides some biological control of this scale.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Monday, April 6, 2009
Greenhouse - Iron & Manganese Toxicity
Iron and manganese toxicity can be a problem in some greenhouse crops if pH drops too low. The following is an article on the subject.
Check the pH of growing media to adjust pH if necessary. Zonal geranium, American marigold, and all types of impatiens are susceptible to iron/manganese toxicity, a nutritional disorder associated with low growing medium pH. Symptoms show as speckling (numerous very small brown spots) on the leaves of geraniums and marigolds, usually beginning on the edges. Maintain the pH within the range of 6.0-6.6 to prevent toxicity. If the pH drops below this range, the risk for toxicity increases because at low pH too much iron and manganese becomes available to the plants. Note that ivy geraniums require a lower pH (5.5-6.0) and more iron than zonal geraniums.
Common causes of iron/manganese toxicity include: acidic growing medium pH, use of acid-forming fertilizers (e.g., 20-10-20, 15-6-17, 15-15-15), inappropriate use of acid injection, and unnecessary use of supplemental micronutrient fertilizers. Watering with acidified water and fertilizing with iron chelates benefit plants like petunia and calibrachoa, but are not recommended and will cause problems on species sensitive to low pH and iron toxicity.
Preventing iron/manganese toxicity starts with adequate liming of the growing medium to the pH range of 6.0-6.6 before planting. “High” pH reduces the availability of iron and manganese. After planting, fertilizers with low potential acidity (e.g.,Cal-Mag 15-5-15, 15-5-25, 15-0-15) should be applied to susceptible species to raise or maintain desirable pH. Regular pH monitoring should be done and, if necessary, liquid limestone can be used to raise the pH of the growing medium. Many geranium growers treat their plants with liquid limestone as a routine preventive treatment. The label for Cleary’s Limestone F suggests using a 100:1 injector to dilute and apply 1 gallon of product. Two applications of 2 qt./100 gal. flowable lime applied 1 week apart has a similar effect to a single drench with 4 qt./100 gal. The effectiveness of liquid limestone depends on the volume applied/depth the solution reaches. Foliage should be rinsed after the liquid limestone is applied to remove any residue.
Research at North Carolina State University indicated that there are three possible causes for the sudden pH decline associated with micronutrient toxicities. The causes are phosphorus deficiency, high production temperature and high light intensity. For more information see the recently published article: Sudden Substrate pH Decline.
Reprinted from "pH, Iron/Manganese Toxicity Spring Crops" by Douglas Cox, University of Massachusetts; Leanne Pundt, University of Connecticut; and Tina Smith, University of Massachusetts in the New England Greenhouse Update http://www.negreenhouseupdate.info/greenhouse_update/?p=2560
Check the pH of growing media to adjust pH if necessary. Zonal geranium, American marigold, and all types of impatiens are susceptible to iron/manganese toxicity, a nutritional disorder associated with low growing medium pH. Symptoms show as speckling (numerous very small brown spots) on the leaves of geraniums and marigolds, usually beginning on the edges. Maintain the pH within the range of 6.0-6.6 to prevent toxicity. If the pH drops below this range, the risk for toxicity increases because at low pH too much iron and manganese becomes available to the plants. Note that ivy geraniums require a lower pH (5.5-6.0) and more iron than zonal geraniums.
Common causes of iron/manganese toxicity include: acidic growing medium pH, use of acid-forming fertilizers (e.g., 20-10-20, 15-6-17, 15-15-15), inappropriate use of acid injection, and unnecessary use of supplemental micronutrient fertilizers. Watering with acidified water and fertilizing with iron chelates benefit plants like petunia and calibrachoa, but are not recommended and will cause problems on species sensitive to low pH and iron toxicity.
Preventing iron/manganese toxicity starts with adequate liming of the growing medium to the pH range of 6.0-6.6 before planting. “High” pH reduces the availability of iron and manganese. After planting, fertilizers with low potential acidity (e.g.,Cal-Mag 15-5-15, 15-5-25, 15-0-15) should be applied to susceptible species to raise or maintain desirable pH. Regular pH monitoring should be done and, if necessary, liquid limestone can be used to raise the pH of the growing medium. Many geranium growers treat their plants with liquid limestone as a routine preventive treatment. The label for Cleary’s Limestone F suggests using a 100:1 injector to dilute and apply 1 gallon of product. Two applications of 2 qt./100 gal. flowable lime applied 1 week apart has a similar effect to a single drench with 4 qt./100 gal. The effectiveness of liquid limestone depends on the volume applied/depth the solution reaches. Foliage should be rinsed after the liquid limestone is applied to remove any residue.
Research at North Carolina State University indicated that there are three possible causes for the sudden pH decline associated with micronutrient toxicities. The causes are phosphorus deficiency, high production temperature and high light intensity. For more information see the recently published article: Sudden Substrate pH Decline.
Reprinted from "pH, Iron/Manganese Toxicity Spring Crops" by Douglas Cox, University of Massachusetts; Leanne Pundt, University of Connecticut; and Tina Smith, University of Massachusetts in the New England Greenhouse Update http://www.negreenhouseupdate.info/greenhouse_update/?p=2560
Landscape - Scale Insects: Euonymus Scale
This is the fourth in a series on scale insects in the landscape. This post is on the Euonymus scale. Information is from the University of Maryland.
Euonymus Scale (Unaspis euonymi (Comstock), Family Diaspididae
Plants damaged: Boxwood, camellia, and evergreen euonymus – especially Euonymus japonica.
Damage Symptoms: Yellowing of foliage and dieback of twigs and general thinning of infested plants.
Life Cycle: This armored scale overwinters as 3rd instar females. Crawlers appear in May and continue for 4 – 5 weeks. Second generation adults are out in July with crawlers present from August through September. The females are dark brown, oyster shell shaped and usually found on the stems. Males are smaller, white and mostly found on the leaves.
Monitoring: Look for chlorotic foliage with yellowing spotting or banding on the needles. Look for overwintering scale on the needles.
Control: A mixture of 1% horticultural oil and Distance does a great job of controlling this scale. Dinotefuran (Safari) applied as a soil drench also works well.
Euonymus scale. Photo from Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Euonymus Scale (Unaspis euonymi (Comstock), Family Diaspididae
Plants damaged: Boxwood, camellia, and evergreen euonymus – especially Euonymus japonica.
Damage Symptoms: Yellowing of foliage and dieback of twigs and general thinning of infested plants.
Life Cycle: This armored scale overwinters as 3rd instar females. Crawlers appear in May and continue for 4 – 5 weeks. Second generation adults are out in July with crawlers present from August through September. The females are dark brown, oyster shell shaped and usually found on the stems. Males are smaller, white and mostly found on the leaves.
Monitoring: Look for chlorotic foliage with yellowing spotting or banding on the needles. Look for overwintering scale on the needles.
Control: A mixture of 1% horticultural oil and Distance does a great job of controlling this scale. Dinotefuran (Safari) applied as a soil drench also works well.
Euonymus scale. Photo from Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Sunday, April 5, 2009
Landscape and Nursery - Plants for Delaware Landscapes Featured at the 2009 UDBG Spring Plant Sale #16
This year, the University of Delaware Botanic Garden spring benefit plant sale features those plants that add to the biodiversity of the landscape and offer food and habitat for wildlife, especially insects and the birds that eat them. Many native plants are featured. This is the 16th in a series on plants being offered at the UDBG spring plant sale that are recommended for Delaware landscapes.
Wild red cherry, also known as pin cherry. Photo by Robert W. Freckmann, University of Wisconsin - Stevens Point
Swamp Azalea. Photo by Jim Stasz @ USDA-NRCS PLANTS Database
For more information on the 2009 UDBG Spring Plant Sale go to http://ag.udel.edu/udbg/events/annualsale.html
Wild red cherry, also known as pin cherry. Photo by Robert W. Freckmann, University of Wisconsin - Stevens Point
Swamp Azalea. Photo by Jim Stasz @ USDA-NRCS PLANTS Database For more information on the 2009 UDBG Spring Plant Sale go to http://ag.udel.edu/udbg/events/annualsale.html
Landscape - Scale Insects: European Fruit Lecanium
This is the third in a series on scale insects in the landscape. It is a description of the European Fruit Lecanium. Information is from the University of Maryland.
European Fruit Lecanium (Parthenolecanium corni), Family Coccidae
Plants Damaged: This soft scale occurs on many shade tree species including hawthorn, red maple, pyracantha, and other plants in the rose family. The European fruit lecanium is a common soft scale insect pest of shade trees and other woody ornamental plants in Maryland (and Delaware). This species feeds on a wide range of host plants and is considered polyphagous. Populations of this pest build up quickly so monitoring for this pest on potential host plants is important.
Damage Symptoms: Feeding damage may cause curled, chlorotic foliage that may drop prematurely. Smaller infested branches are weakened due to feeding injury or in some cases may be killed. Also, when this soft scale species is feeding on leaves and twigs, a large quantity of honeydew is secreted.
Life Cycle: The 2nd instar females overwinter on the branches. The females will start to swell-up in May and crawlers emerge in late May to early June. Nymphs move out onto foliage where they feed in summer and migrate back to the stems and trunk to overwinter.
Monitoring: Look for sooty mold growing on the honeydew excreted on the foliage and branches. Inspect branches using a 10 -16X magnifier for crawlers
Control: Distance and 1% horticultural oil applied when crawlers are active gives good control. Another option is soil applications of imidacloprid or dinotefuran as a soil drench.
European Fruit Lecanium. Photo by Raymond Gill, California Department of Food and Agriculture, Bugwood.org
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
European Fruit Lecanium (Parthenolecanium corni), Family Coccidae
Plants Damaged: This soft scale occurs on many shade tree species including hawthorn, red maple, pyracantha, and other plants in the rose family. The European fruit lecanium is a common soft scale insect pest of shade trees and other woody ornamental plants in Maryland (and Delaware). This species feeds on a wide range of host plants and is considered polyphagous. Populations of this pest build up quickly so monitoring for this pest on potential host plants is important.
Damage Symptoms: Feeding damage may cause curled, chlorotic foliage that may drop prematurely. Smaller infested branches are weakened due to feeding injury or in some cases may be killed. Also, when this soft scale species is feeding on leaves and twigs, a large quantity of honeydew is secreted.
Life Cycle: The 2nd instar females overwinter on the branches. The females will start to swell-up in May and crawlers emerge in late May to early June. Nymphs move out onto foliage where they feed in summer and migrate back to the stems and trunk to overwinter.
Monitoring: Look for sooty mold growing on the honeydew excreted on the foliage and branches. Inspect branches using a 10 -16X magnifier for crawlers
Control: Distance and 1% horticultural oil applied when crawlers are active gives good control. Another option is soil applications of imidacloprid or dinotefuran as a soil drench.
European Fruit Lecanium. Photo by Raymond Gill, California Department of Food and Agriculture, Bugwood.org
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Saturday, April 4, 2009
Landscape - Scale Insects: Cottony Camellia/Taxus Scale
This is the second in a series on scale insects in the landscape. It is a description of the Azalea bark scale. Information is from the University of Maryland.
Cottony Camellia/Taxus Scale (Pulvinaria floccifera), Family Coccidae
Plants Damaged: Taxus yews, camellia, holly, rhododendron, Japanese maple, English ivy, and mulberry.
Damage Symptoms: Yellowing of foliage and dieback of plant in severe infestations. This soft scale produces large amounts of honeydew on which sooty mold will grow.
Life Cycle: Adult females are oval and yellowish tan. This scale can reproduce quickly with over 1,000 eggs per female. There is one generation a year. Crawlers begin to appear in mid- June. The scale tends to accumulate on the undersides of foliage.
Monitoring: Look for sooty mold and honey dew on the foliage. Examine the undersides of leaves for the white cotton-like sacs.
Control: Wait for eggs to hatch and then treat with the insect growth regulator Distance or oil. Soil injections of imidacloprid (Merit in the landscape, Marathon in nurseries) can be applied in April.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Cottony Camellia/Taxus Scale (Pulvinaria floccifera), Family Coccidae
Plants Damaged: Taxus yews, camellia, holly, rhododendron, Japanese maple, English ivy, and mulberry.
Damage Symptoms: Yellowing of foliage and dieback of plant in severe infestations. This soft scale produces large amounts of honeydew on which sooty mold will grow.
Life Cycle: Adult females are oval and yellowish tan. This scale can reproduce quickly with over 1,000 eggs per female. There is one generation a year. Crawlers begin to appear in mid- June. The scale tends to accumulate on the undersides of foliage.
Monitoring: Look for sooty mold and honey dew on the foliage. Examine the undersides of leaves for the white cotton-like sacs.
Control: Wait for eggs to hatch and then treat with the insect growth regulator Distance or oil. Soil injections of imidacloprid (Merit in the landscape, Marathon in nurseries) can be applied in April.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Turf and Landscape - Know Your Soluble Fertilizers 4
This is the fourth in a series on soluble fertilizers for use in turf and landscapes. This post is on triple superphosphate, a phosphorus fertilizer.
Concentrated Superphosphate also known as triple superphosphate, is gray granular material containing 46% water and citric acid soluble phosphate (P2O5 ) of which the water-soluble portion is generally around 85%. This material has very good physical properties and is often used as a conditioner in complete mix fertilizers. The salt index is very low (0.21) and there is no overall effect on soil reaction. Concentrated superphosphate granules are large and are not typically used in golf green fertilizers, but may be found in lawn and fairway grade fertilizers. In most tests with fertilizer P sources, no turfgrass response differences have been observed between sources.
Reprinted from "Selected Fertilizers Used in Turfgrass Fertilization" by J.B. Sartain & J.K. Kruse, University of Florida Cooperative Extension.
Concentrated Superphosphate also known as triple superphosphate, is gray granular material containing 46% water and citric acid soluble phosphate (P2O5 ) of which the water-soluble portion is generally around 85%. This material has very good physical properties and is often used as a conditioner in complete mix fertilizers. The salt index is very low (0.21) and there is no overall effect on soil reaction. Concentrated superphosphate granules are large and are not typically used in golf green fertilizers, but may be found in lawn and fairway grade fertilizers. In most tests with fertilizer P sources, no turfgrass response differences have been observed between sources.
Reprinted from "Selected Fertilizers Used in Turfgrass Fertilization" by J.B. Sartain & J.K. Kruse, University of Florida Cooperative Extension.
Friday, April 3, 2009
Landscape and Turf - Soil Health
The following is information on soil health, a term used to describe those biological, chemical, and physical characteristics of soils that promote good plant growth.
According to the Cornell Soil Health group, “soil health describes the capacity of a soil to be used productively without adversely affecting its future productivity, the ecosystem or the environment.” Soil health emphasizes the integration of biological with chemical and physical measures of soil quality that affect plant growth and the environment.
From a biological standpoint, soil health relates directly to the root environment and organisms that inhabit the soil. A healthy soil will be one that has few limits to root growth; supports high numbers of beneficial soil organisms such as earthworms; supports a diverse microbial community with high levels of beneficial bacteria, fungi, actinomycetes, protozoa, and nematodes and low levels of plant pathogens (such as root rot fungi, bacterial and fungal wilt organisms, soft rot bacteria, and plant parasitic nematodes). In a healthy soil, plant root systems explore a large portion of the soil volume, plants are under reduced stress, and pest problems are minimal. A healthy soil will also support mineralization or organic matter by soil microorganisms at levels appropriate to the climate.
From a chemical standpoint, healthy soils will be at a proper pH (6.0-6.8 in most soils); have a high cation exchange capacity; have optimal levels of calcium, magnesium, and potassium held on exchange sites; contain optimal but not excessive levels of other mineral nutrients needed by plants, have high levels of organic matter in various levels of decomposition and high levels of stable humus; support aerobic mineralization processes; and be free of toxic minerals from natural sources (such as high free aluminum levels) or from toxic chemical contaminants.
From a physical standpoint, healthy soils will have high levels of stable aggregates in the topsoil (creating a stable granular structure); an optimal mix of pore sizes (macropores and micropores) so that it is well aerated in root zone, well drained, but also has a high available water holding capacity; and a low bulk density relative to the soil texture. They will be free of compaction which limits root growth. Healthy soils are highly permeable to water and not prone to crusting.
Gordon Johnson, Extension Horticulture Agent, UD, Kent County.
According to the Cornell Soil Health group, “soil health describes the capacity of a soil to be used productively without adversely affecting its future productivity, the ecosystem or the environment.” Soil health emphasizes the integration of biological with chemical and physical measures of soil quality that affect plant growth and the environment.
From a biological standpoint, soil health relates directly to the root environment and organisms that inhabit the soil. A healthy soil will be one that has few limits to root growth; supports high numbers of beneficial soil organisms such as earthworms; supports a diverse microbial community with high levels of beneficial bacteria, fungi, actinomycetes, protozoa, and nematodes and low levels of plant pathogens (such as root rot fungi, bacterial and fungal wilt organisms, soft rot bacteria, and plant parasitic nematodes). In a healthy soil, plant root systems explore a large portion of the soil volume, plants are under reduced stress, and pest problems are minimal. A healthy soil will also support mineralization or organic matter by soil microorganisms at levels appropriate to the climate.
From a chemical standpoint, healthy soils will be at a proper pH (6.0-6.8 in most soils); have a high cation exchange capacity; have optimal levels of calcium, magnesium, and potassium held on exchange sites; contain optimal but not excessive levels of other mineral nutrients needed by plants, have high levels of organic matter in various levels of decomposition and high levels of stable humus; support aerobic mineralization processes; and be free of toxic minerals from natural sources (such as high free aluminum levels) or from toxic chemical contaminants.
From a physical standpoint, healthy soils will have high levels of stable aggregates in the topsoil (creating a stable granular structure); an optimal mix of pore sizes (macropores and micropores) so that it is well aerated in root zone, well drained, but also has a high available water holding capacity; and a low bulk density relative to the soil texture. They will be free of compaction which limits root growth. Healthy soils are highly permeable to water and not prone to crusting.
Gordon Johnson, Extension Horticulture Agent, UD, Kent County.
Landscape - Scale Insects: Azalea Bark Scale
This is the first in a series on scale insects in the landscape. It is a description of the Azalea bark scale. Information is from the University of Maryland.
Azalea Bark Scale (Acanthococcus azaleae), Family Erioccicdae
Plants Damaged: This scale is a pest of azaleas and rhododendrons. This scale has been reported on hawthorn, Andromeda, poplar, willow and ornamental cherry trees.
Damage Symptoms: Azalea bark scale has become recognized as a prominent pest of azaleas. Infested plants usually appear chlorotic and unthrifty. Infested plants are often covered with sooty mold, a black fungus that grows on the honeydew excreted by the azalea bark scales as they feed. Eventually twigs may die back.
Life Cycle: As the female azalea bark scale matures, it secretes white, waxy threads, which become felted or matted into a thick covering over its entire body. Females lay eggs in this white wax. As the female lays eggs, its body shrivels gradually as the egg sac fills with eggs. Eggs are laid in May. They hatch in central Maryland in late May to early June. Individual crawlers are active and moving for 12 – 24 hours. New crawlers continue to emerge over a couple of weeks. There are two generations in Maryland. This new generation matures during the summer and produces eggs in September. Mature females tend to feed in crotches and on twigs. Adult males, two-winged and tiny, tend to feed on the leaves. Azalea bark scale overwinters as immatures in the forks of the twigs.
Control: If the population is low and damage is minimal, look for beneficial insects which do a good job controlling this insect. If necessary, apply a dormant spray for overwintering nymphs on twigs. In summer when crawlers are active, you can use a summer rate (0.5 – 1.0%) of horticultural oil for control.
Azalea bark scale. Photo from the United States National Collection of Scale Insects Photographs Archive, USDA Agricultural Research Service, Bugwood.org
Azalea bark scale crawler activity.
Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Azalea Bark Scale (Acanthococcus azaleae), Family Erioccicdae
Plants Damaged: This scale is a pest of azaleas and rhododendrons. This scale has been reported on hawthorn, Andromeda, poplar, willow and ornamental cherry trees.
Damage Symptoms: Azalea bark scale has become recognized as a prominent pest of azaleas. Infested plants usually appear chlorotic and unthrifty. Infested plants are often covered with sooty mold, a black fungus that grows on the honeydew excreted by the azalea bark scales as they feed. Eventually twigs may die back.
Life Cycle: As the female azalea bark scale matures, it secretes white, waxy threads, which become felted or matted into a thick covering over its entire body. Females lay eggs in this white wax. As the female lays eggs, its body shrivels gradually as the egg sac fills with eggs. Eggs are laid in May. They hatch in central Maryland in late May to early June. Individual crawlers are active and moving for 12 – 24 hours. New crawlers continue to emerge over a couple of weeks. There are two generations in Maryland. This new generation matures during the summer and produces eggs in September. Mature females tend to feed in crotches and on twigs. Adult males, two-winged and tiny, tend to feed on the leaves. Azalea bark scale overwinters as immatures in the forks of the twigs.
Control: If the population is low and damage is minimal, look for beneficial insects which do a good job controlling this insect. If necessary, apply a dormant spray for overwintering nymphs on twigs. In summer when crawlers are active, you can use a summer rate (0.5 – 1.0%) of horticultural oil for control.
Azalea bark scale. Photo from the United States National Collection of Scale Insects Photographs Archive, USDA Agricultural Research Service, Bugwood.org
Azalea bark scale crawler activity.Information from "Scales Commonly Encountered in Maryland Landscapes and Nurseries" by Stanton Gill, Extension Specialist in IPM for Nurseries and Greenhouses,and Suzanne Klick and Shannon Wadkins, Technicians, Central Maryland Research and Education Center University of Maryland Cooperative Extension.
Thursday, April 2, 2009
Greenhouse - Pilotus exaltatus 'Joey'
The following are pictures and descriptions of one of the newer flowering annuals for greenhouse production from Australia originally.
Pilotus exaltatus 'Joey' is a sun and heat loving plant native to Australia. It has a unique flower and can be used in gallon pots or mixed combos. From seed it is a 16 week crop, and from plugs a 10 week crop. This is a day neutral plant, and no plant growth regulators are necessary.
Information and pictures from the April 11, 2008 edition of the Greenhouse TPM/IPM Weekly Report from the University of Maryland Cooperative Extension Central Maryland Research and Education Center.
Pilotus exaltatus 'Joey' is a sun and heat loving plant native to Australia. It has a unique flower and can be used in gallon pots or mixed combos. From seed it is a 16 week crop, and from plugs a 10 week crop. This is a day neutral plant, and no plant growth regulators are necessary.
Information and pictures from the April 11, 2008 edition of the Greenhouse TPM/IPM Weekly Report from the University of Maryland Cooperative Extension Central Maryland Research and Education Center.
Wednesday, April 1, 2009
Greenhouse and Nursery - Pavement Ants
Pavement ants are an occasional pest in greenhouses and nurseries. The following is more information.
Pavement Ants, Tetramorium caespitum
Pavement ants can damage plants in the greenhouse. They have been found causing damage on vinca, petunia, marigold, and pansy crops in the past but could attack most plants. They feed on the roots and girdle the stems of plants causing them to collapse.
Identification: The pavement ant is dark brown with light colored legs. They have 12-segmented antennae with a 3- segmented club. On females, the thorax has a pair of small spines on the dorsal side. The males do not have these spines. The pedicel (area between thorax and abdomen) is 2-segmented.
Control: DuraGuard ME has a label for use in greenhouses and nurseries and will control ants. Apply this as a soil drench.
Pavement Ant. Photo from the University of Maryland.
Information adapted from the March 28, 2008 edition of the Greenhouse TPM/IPM Weekly Report from the University of Maryland Cooperative Extension Central Maryland Research and Education Center
Pavement Ants, Tetramorium caespitum
Pavement ants can damage plants in the greenhouse. They have been found causing damage on vinca, petunia, marigold, and pansy crops in the past but could attack most plants. They feed on the roots and girdle the stems of plants causing them to collapse.
Identification: The pavement ant is dark brown with light colored legs. They have 12-segmented antennae with a 3- segmented club. On females, the thorax has a pair of small spines on the dorsal side. The males do not have these spines. The pedicel (area between thorax and abdomen) is 2-segmented.
Control: DuraGuard ME has a label for use in greenhouses and nurseries and will control ants. Apply this as a soil drench.
Pavement Ant. Photo from the University of Maryland.Information adapted from the March 28, 2008 edition of the Greenhouse TPM/IPM Weekly Report from the University of Maryland Cooperative Extension Central Maryland Research and Education Center
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