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PLANT DISEASE TREATMENT <br />Maximum Application Rates, Appli cation Interval, and Season Maximum Application Rates are <br />listed below. Weight of Copper Sulfate Crystals in lbs is followed by weight expressed as metallic <br />copper, e.g ., 1 lb Copper Su lfate Crysta ls equals 0 .25 lb metallic copper. <br />Apple: Fireblight-Mix 5 lbs of Copper Sulfate Crystals in 100 gals of water and spray uniformly . <br />Apply in dormant season up to silver tip stage. After si lver tip, severe burn will occur on any <br />exposed green tissue. Do not m ix lime to make a Bordeaux spray for th is treatment Do not <br />exceed 641bs (16 lbs metallic copper) per acre per year. D ormant use: Make one application at <br />no more than 32 lbs (8 lbs metallic copper) per acre. Silver tip use: Make one application at no <br />more than 24 lbs (6 lbs metallic copper) per acre. <br />Grape (Dormant): Powdery Mildew-Apply in spring before bud-swell and before any green <br />tissue is present. Use 4 lbs of Copper Sulfate Crystals per 100 gals of water. Apply in a high <br />volume spray of 300 gals water per acre. Direct spray to thoroughly wet the dormant vine , <br />especially the bark of the trunk, head or cordons. Do not apply more than 12.0 lbs (3 .0 lbs <br />metallic copper) per acre per application. Minimum retreatment interval is 3 days. Do not exceed <br />80 .0 lbs (20.0 lbs metallic copper) per acre per year. <br />Potatoes: To enhance vine -kill and suppress late blight-apply 10 lbs per acre in 10 to 100 <br />gals of water (ground equipment) or in 5 to 1 0 gals (aerial equipment) with Diquat at vine-kill to <br />enhance vine desiccation and suppress late blight. Additional applications can be made with <br />Diquat if needed to within 7 days of harvest. Copper Sulfate Crystals may be applied alone until <br />harvest to suppress late blight. NOTE: This product can be mixed with Diquat for use on <br />potatoes in accordance with the most restrictive of label limitations and precautions. No label <br />dosage rates should be exceeded. Do not apply more than 10 lbs (2.5 lbs metallic copper) per <br />acre per application. Minimum retreatment interval is 5 days. Do not exceed 100 lbs. (25 lbs <br />metallic copper) per acre per year. <br />BORDEAUX SPRAY MIXTURE <br />Understanding Bordeaux Formulations: If the Bordeaux mixture instructions read 10-10-100, the <br />first figure indicates the number of lbs of Copper Sulfate Crystals. The second figure is the lbs of <br />hydrated spray lime and the third figure is the gallons of water to be used . Use as a full coverage <br />spray. In the instruction below, weight of copper sulfate in lbs is followed by weight expressed as <br />meta llic copper, e.g., 1 lb Copper Sulfate Crystals equals 0.25 lb metallic copper. <br />Preparation of Bordeaux Spray Mixture: Fill a tank 1/4 full with water. Then, with agitator <br />running, mix in Copper Sulfate Crystals through a copper , bronze, stain less steel or plastic <br />screen. Add water so the tank is 3/4 full. Mix in the hydrated spray lime through the screen and <br />finish filling the tank with water. <br />Alm ond, Apricot, Peach, Nectarine: Shot Hole Fungus-Prepare a 10-10-100 Bordeaux and <br />apply as a dormant spray in late fall or early sprin g . Do not apply more than 32 lbs copper <br />sulfate (8 lbs metallic copper) per acre per application . Minimum retreatment interval is 7 days. <br />Do not exceed 72 lbs (18 lbs metallic copper) per acre per year. <br />Almond, Apricot, Cherry, Peach, Nectarine, Plum, Prune : Brown Rot Blossom B lig ht- <br />Prepare a 10-10-100 Bordeaux and apply when buds begin to swell (late dormant). Do not apply <br />more than 32 lbs (8 lbs metallic copper) per acre per application . Minimum retreatment interval is <br />7 days . Do not exceed 72 lbs (18 lbs metall ic copper) per acre per year. <br />Blueberries: Bacterial Canker (Not for use in California)-Prepare and apply an 8-8-100 <br />Bordeaux mixture in the fall before heavy rains begin and again 4 weeks later. Do not apply more <br />than 8.4 lbs (2.1 lbs metallic copper) per acre per application. Minimum retreatment interval is 7 <br />days. Do not exceed 33.6 lbs (8.4 lbs metallic coppet) per acre per year. <br />Bulbs (Easter Lil y): Botrytis Blight-Prepare a 10-10-100 Bordeaux mixture and apply as a <br />foliar spray to 1 acre. Apply for thorough coverage beginning at the first sign of disease and <br />repeat as needed to control disease at 7 to 1 0 day intervals. Use the shorter intervals during <br />periods of frequent rains or when severe disease cond itions persist. Avoid spray just before <br />flower cutting season if residues are a problem. Do not apply more than 10 lbs (2 .5 lbs metallic <br />8 <br />6.3.A. - Page 131