Downy mildew disease

Figure 16.1 Effect of Acacia arabica gum treatment on germination and seedling vigor of pearl millet under laboratory conditions (a) Effect of Acacia arabica gum treatment on control of downy mildew disease of pearl millet caused by Sclerospora graminicola under green house conditions (b) and field conditions (c).

There, the fungicidal activity was detected and an optimization program carried out [88] that finally led after three years of work and the preparation of over 700 analogs [88b] to an optimized structure, famoxadone for patents see [89]. In-vivo structure-activity relationships have been reported with the oomycetes Phy-tophthora infestans and Plasmopara viticola [88]. Famoxadone was announced in 1996 as a broad spectrum fungicide for the control of diseases caused by Ascomy-cetes and Basidiomycetes in various crops and particularly against downy mildew diseases caused by oomycetes in potato, vines and vegetables [90]. 

Raj, S.N., Sarosh, B.R., and Shetty, H.S. 2006. Induction and accumulation of polyphenol oxidase activities as implicated in development of resistance against pearl millet downy mildew diseases. Fund. Plant Biol., 33 563-571. 

Sarathchandra, R. G., Jaj, S. N. 2004. A chitosan formulation Alexa induce Downy Mildew disease resistance and growth promotion in pearl millet. Crop Protection 23 881-888. 

Intercropping (seep.259) a disease-susceptible variety with a resistant one in the vegetable plot is a technique that is also looking promising, on a field scale at least. Research trials have shown that lettuces susceptible to downy mildew can be protected if, in the row, each plant alternates with one of a resistant lettuce variety. 

FUngal diseases Black, sunken patches on leaves farleft) are caused by the fungal disease downy mildew. Plok off Infeoted leaves and dispose of them Immediately next year, be sure to rotate crops. Leek rust Heft) need not spell disaster for your orops, but In future years, look for leek oultivars that offer some resistance to this fungal Infeotlon. 

Lettuce is the most pest- and disease-prone member of the Asteraceae. Common pests include slugs, cutworm, leaf aphids, and root aphids. Linder cover, downy mildew and gray mold (botrytis) can be a problem, especially in cool, damp conditions. Cultivars with resistance to aphids, downy mildew, and various physiological disorders are available. For more advice and information, see the A-Z of Plant Problems ipp.320-341). 

Escape Shorter crop growth period and/or early ripening to be able to avoid the critical infestation period, or to have enough yield before the infestation becomes too severe (potato/late blight onion/downy mildew carrot/carrot fly) One or more monofactorial and multifactorial, durable resistance traits against pest and disease affecting yield and/or quality (scab/apple, late blight/potato, lettuce/downy mildew, yellow and brown leaf rust/wheat) weed competition by an allelochemical ability... 

Urech, P.A., Schwinn, F., and Staub, T. 1977. CGA 48988, a novel fungicide for the control of late blight, downy mildews and related soil-borne diseases. Proc. Br. Crop Prot. Conf., 9th 2, 623-6731. 

Uses as fungicide to control late blights of potatoes and tomatoes downy mildews of hops, vines, lettuce, onions, soybeans and other crops many diseases in flowers and ornamentals and often used in combination with other fungicides, etc. 

Fluopicolide [217] is a Bayer CropScience fungicide for the control of oomycete diseases such as downy mildew, damping-off, and late blight in vegetables, cucumber, tomatoes, cereals, and coffee. 

Leaves with light-colored spots on upper leaf surfaces. Cause Downy mildew. Leaves infected with this fungal disease have spots covered with white fuzzy growth on the undersides. Spray plants with copper when symptoms first appear. 

Heads with black spots on surfoce. Cause Downy mildew. Control this fungal disease by spraying plants with a baking-soda-and-soap spray (1 teaspoon baking soda, 1 teaspoon liquid dish soap, 1 quart water) or copper at the first sign of disease. Repeat weekly if weather is wet. Prevent problems by planting Cloud Nine , which is somewhat tolerant of downy mildew. 

Leaves mottled yellow between veins leaf undersideS ave purple spots. Cause Downy mildew. A S the disease progresses, older leaves turn brown and die and younger leaves become infected. Treat plants with a dilute solution of copper spray to control see the caution on page 213 before spraying. Prevent problems by planting tolerant cultivars such as Fanci-pak , Liberty , Poinsett 76 , and Slicemaster . 

Ripening fruit clusters infected with downy mildew may have a mix of hard, reddish green, infected berries and soft, juicy, healthy berries. The fuzzy coating on fruit apparent early in the season may not be present. For information on controls for these diseases, see Leaves with a white powdery coating on the upper surfaces below for powdery mildew symptoms for downy mildew, see Leaves with white, cottony growth on undersides below. 

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