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Weeds and Pests
Plant Disease Control Chemicals:
Plant Disease Control Chemicals:
Always attempt to control disease problems with cultural practices; pruning, better watering regime and methodology, proper nutritional balance, and resistant cultivar selection. If and when chemicals are needed, select the least toxic to affect control. The application of dormant (superior) oil and lime-sulfur to dormant fruit and deciduous trees is an excellent sanitizer to begin with. Beyond that here are the recommended sprays for most disease problems:
Bordeaux mixture - a copper based fungicide in combination with lime. Copper is the only material that is toxic to the pathogen, and, in sufficient concentrations could be to the plant as well. Bordeaux can be used as a concentrated dormant spray, and is made by mixing 10 pounds of copper sulfate, 10 pounds of hydrated lime, and 100 gallons of water (formula: 10:10:100). Being too "hot" to use on trees in leaf, the compound is usually formulated as 8:8:100, or for actively growing plants a formula like 2:2:100, or 2:6:100 may be used. If plants are sensitive to Bordeaux, then the concentration of lime can be increased accordingly (i.e. 2:24:100).
Lime-Sulfur - created by boiling lime and sulfur together. This and Bordeaux mixture can control a wide range of fungal diseases in most woody and herbaceous plants. Tomatoes, melons and grape are sensitive to sulfur containing materials. Avoid using when temperatures are high.
Dithiocarbamates - include thriam, ferbam, maneb, zineb, and mancozeb. All control a wide range of seed and bulb treatment for vegetables, flowers, and grasses, and also for foliage diseases like rusts in lawns. Zineb is sold as Dithane Z-78, and is an excellent foliar and soil fungicide for the control of leaf spots, blights, fruit rots of vegetables, flowers, trees, and shrubs.
Chlorotahalonil - is sold under many trade names (i.e. Bravo) is used to control everything from Botrytis on greenhouse tomatoes to numerous leaf spots, blights, downy mildews, rusts, scabs, and rots, plus more on all horticultural plants.
Captan - an excellent fungicide for control of leaf spots, blights, fruit rots, vegetables, and turf. It has also been used as a seed protectant for those same crops. It can also be used to repel seed eating birds.
Benomyl - aka - Tersan 1991 and others, is a safe broad-spectrum fungicide. It is particularly effective against scab of apples, powdery mildew, and fruit rots in general. It is highly effective against Sclerotinia, Botrytis, Fusarium, and Verticillium. Thiophanate methyl (aka - Fungo & TopsinM) in the same family as beonmyl, is used on turf to control powdery and downy mildews, as well as a broad spectrum of other Botrytis diseases, leaf spots and scabs. It can also be used as a soil drench to control soil-borne pathogens attacking ornamental plants.
Antibiotics - Streptomycin or streptomycin sulfate is sold to control fire blight on pome fruit trees and as a soil drench to control geranium root rot caused by Xanthomonas spp.
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