Anthracnose on Dogwoods and Other Trees

Transcription

1 Anthracnose on Dogwoods and Other Trees Several cultural practices are recommended for control. Healthy trees can fight off the infection. To reduce stress, apply 3-4 inches of mulch around the base of the tree covering the roots. Keep the mulch 3-4 inches from the tree trunk itself. Water only during dry periods. Fertilize only moderately and only if necessary, avoid high nitrogen fertilizers, which promotes the growth of succulent sprouts that are more susceptible to the disease. Plant trees in the sun and plant resistant varieties. Fungicides are only suggested if the disease is persistent after cultural practices have been used without improvement. Apply fungicides at label rates and directions, beginning at bud break or first sign of disease in the spring. Fungicide options include: Neem oil (Garden Safe Fungicide): repeat applications at 7- to 14-day intervals. Chlorothalonil (Daconil Weather Stik, Daconil Ultrex, Fertilome Landscape & Garden Fungicide): repeat applications at 7- to 14-day intervals. Mancozeb (Dithane DF Rainshield, Mancozeb DG, Dithane T/O Rainshield, Pentathlon LF, Protect T/O): repeat applications at 7- to 10-day intervals. Propiconazole (Banner Maxx, Fertilome Liquid Systemic Fungicide, Fungonil Lawn & Garden Disease Control): repeat applications at 14- to 28-day intervals. Propiconazole is the preferred fungicide for dogwoods. Bagworms on Evergreen Trees The insect is most easily identified by the bag or case the caterpillar builds around itself on the plant that it is feeding from. The bag is made from silk that the worm weaves along with bits of the host plant s leaves. When fully mature the caterpillars bag may be 1 ½- 2 inches long. The female will lay 300-1,000 eggs inside the bag. The eggs hatch from late-may to mid June. The larvae are most susceptible to treatment mid to late June.

2 Pest Control Timing of Treatment Remarks Bagworm The first two treatments are organic and safe for the environment. Light infestation Remove and burn bags Bacillus thuringensis (Bt) August to May Treat when larvae are young mid-late June Overwintering eggs remain inside the bags until hatching in late May. Destroy the bags; eggs will hatch from bags thrown on the ground. Lightly misting the foliage is sufficient. Mist blower treatments are effective. Pemethrin Malathion Apply when bags are less than ½ inch. May in coastal Virginia. Avoid using in public areas Control is much less effective if applied later than mid-june Pest Control Timing of Treatment Remarks Oak Borer Peach Apple/fruit tree borer and mock orange Treat trunk to ground in early June Treat trunks and soil around base in July and repeat in 6 weeks Heavy infestations in evennumbered years. Round-headed and flatheaded borer Imidcloprid Treat bark of trunk and branches in early May, June and early July Imidcloprid as soil drench before infestation in April Dogwood Borer Treat bark of trunk and branches in mid-may and repeat in 6 weeks

3 For Pine Bark Beetles Virginia Tech Recommends Have dead or heavily infested limbs or trees removed in winter when the beetles are dormant. Burn all refuse. Do not keep wood chips as eggs may remain in the pieces under the bark. Look in the yellow pages under Tree(s) for arborists that are licensed and certified, and include insect management or control in their listing. Pest Control Timing of Treatment Remarks Bark Beetles (Conifers) Treat unhealthy, weakened, or damaged trees in early April, early June, and August if near infested trees. Also effective in preventing spread if sprayed on infested trees or wood before beetles emerge, or in preventing infestations in uninfested wood that is cut but cannot be disposed of immediately. Thoroughly wet all of the bark. Healthy vigorous trees are not likely to be attacked and do not require spraying. Beetles will not reinfest or attack wood or trees dead more than one year. Sanitation Throughout the year, particularly during the growing season, when trees begin dying or wood is cut. Prune out large, dying, or recently dead branches. Dispose of susceptible wood, slash, and bark from stumps by burning. Beetles will not reinfest or attack wood or trees dead longer than one year. Fabraea maculate or Fabraea Leaf is caused by a fungus. Follow label Directions Table Recommended Protectant Pesticides Pesticide Amount of pesticide to use in different amounts of water 1 5 gallons 10 gallons 25 gallons 50 gallons gallon Special Purpose Pesticides (SPP) Captan 50% 2.0 tbsp2 1.6 oz 3.2 oz 0.5 lb 1.0 lb Wettable Powder Malathion 50% 2.0 tsp 1.6 fl oz 3.2 fl oz 8.0 fl oz 1.0 pt Emulsifiable Concentrate Ferbam 76% 1.5 tbsp 1.2 oz 2.4 oz 6.0 oz 12.0 oz Wettable Powder3 Immunox 1.55%4 1.0 tbsp 2.5 fl oz 5.0 fl oz 12.5 fl oz 25.0 fl oz (rates for apples and stone fruits) M-Pede 49% 2.5 fl oz 13 fl oz 26 fl oz 0.5 gal 1.0 gal Liquid5 Sevin 80S6 1.0 tbsp 1.0 oz 2.0 oz 5.0 oz 10.0 oz Sulfur 95% 1.0 tbsp 5.0 tbsp 1.6 oz 4.0 oz 8.0 oz Wettable Powder % WP tsp tbsp oz oz oz

4 1Do not exceed the label rate for any material on any crop. 2A teaspoonful (tsp) or a tablespoonful (tbsp) in this publication refers to a level standard measuring teaspoon or table spoon. 3 Ferbam provides good control of black rot of grapes. It should be added to the general purpose mixture for cedar and quince rust control of apple (early pink to June 10), ferbam should be used on peaches and nectarines during the dormant stage (November or early March) for peach leaf curl control. 4 Immunox may be used to supplement Captan in the GPM for rust and mildew management on apples, peaches, nectarines, cherries, apricots, plums, prunes, and grapes. See following Spray Materials section for disease control spectrum and usage restrictions for each crop. 5 If mites become a problem on apple, peach, or grape, use two sprays of M-Pede at 7-day intervals. 6 Sevin can be used beginning in early June if Japanese beetles become a problem (minor foliar feeding is acceptable). Do not use before this period since it will thin some varieties of apples. 7 Sulfur can be added to the GPM for powdery mildew control on apple. It is sold in concentrations of 52-95%. 8 Systemic Fungicide 3336 WP 50% wettable powder is available as Dragon Systemic Fungicide 3336 WP and Cleary s 3336 WP for use on backyard (non-commercial) fruit trees such as apple, apricot, cherry, nectarine, peach, plum, and prune trees. This fungicide replaces Benlate, which is no longer registered for use. Do not apply 3336 WP within 24 hours of harvest.

5 Trees Moderately Difficult to Transplant Bare Root* (*With the remaining species,we have had limited success even with good after care. Transplanting in fall increases success.) Scientific Name Alnus glutinosa Amelanchier spp. Betula spp. Celtis occidentalis Cercis canadensis Corylus colurna Crataegus crus-galli inermis Crataegus viridis Eucommia ulmoides Prunus subhirtella var. autumnalis Quercus robur Tilia tomentosa Zelkova serrata J Common Name European Alder Serviceberry Birch Hackberry Redbud Turkish Filbert Thornless Cockspur Hawthorn Winter King Winter King Hawthorn Hardy Rubber Tree Higan Cherry English Oak Silver Linden apanese Zelkova Trees Difficult to Transplant Bare Root * (*With the remaining species,we have had limited success even with good after care. Transplanting in fall increases success.) Scientific Name Carpinus spp. Crataegus phaenopyrum Ginkgo biloba Liriodendron tulipifera Nyssa sylvatica Ostrya virginiana Quercus alba Quercus coccinea Quercus imbricaria Quercus macrocarpa Quercus muehlenbergii Quercus prinus Taxodium distichum Ulmus Frontier Ulmus parvifolia Common Name Hornbeam Washington Hawthorn Ginkgo Tulip Tree Tupelo American Hophornbeam White Oak Scarlet Oak Shingle Oak Bur Oak Chinkapin Oak Chestnut Oak Baldcypress Frontier Elm Lacebark Elm Source Cornell University,

6 Trees Easy to Plant Bare Root Scientific Name Acer campestre Acer x freemanii Acer miyabei Acer platanoides Acer pseudoplatanus Acer rubrum Acer saccharum Acer truncatum Catalpa speciosa Cercidiphyllum japonicum Cladrastis kentukea Cornus mas Cornelian Cornus foemina Fraxinus spp. Gleditsia triacanthos Gymnocladus dioicus Koelreuteria paniculata Maackia amurensis Malus spp. ple Parrotia persica Platanus x acerifolia Prunus Accolade Prunus sargentii Prunus serrulata Prunus virginiana Pyrus calleryana Pyrus ussuriensis Quercus bicolor Quercus palustris Quercus rubra Robinia pseudoacacia cultivars: Globosum, Bessoniana, Sorbus alnifolia Sorbus intermedia / aria Syringa reticulata Tilia americana Tilia cordata Tilia euchlora Ulmus americana Common Name Hedge Maple Freeman Maple Trident Maple Norway Maple Sycamore Maple Red Maple Sugar Maple Shantung Maple Northern Catalpa Katsura Tree Yellowwood Cherry Dogwood Gray Dogwood Ash Honeylocust Kentucky Coffee Tree Goldenrain Tree Amur Maackia Persian Parrotia London Plane Tree Accolade Flowering Cherry Sargent Cherry Japanese Flowering Cherry Canada Red Chokecherry Callery Pear Ussurian Pear Swamp White Oak Pin Oak Northern Red Oak Black Locust Purple Robe, Pyramidalis, Twisty Baby Korean Mountain Ash Whitebeam Mountain Ash Japanese Tree Lilac Basswood Littleleaf Linden Crimean Linden and elm American Elm hybrids hybrids except Frontier Source Cornell University,