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PROPERTIES MD USES OF FUNGICIDES ON FRUITS - 1947 (In the March issue 

 of Fruit Notes there appeared a detailed statement concerning the newer 

 fungicides, A similar statement covering the older fungicides is here 

 presented), 



BORDEAUX MIXTURE 



1, Common Uses ; Bordeaux mixture 8-8-100 (Copper sulfate-hydrated 

 lime - ivater) is standard for diseases of grapes and strawberries; also 

 for fall or spring dormant spray for peach leaf curl. If a fungicide is 

 needed (it rarely is) at delayed dormant for apple scab control, Bordeaux 

 may be combined with the oil spray for red mite. Bordeaux 2-6-100 is 

 commonly used during mid-bloom (or when one- third of blossoms are open 

 and again at three-fourths bloom) to prevent fire blight blossom infection 

 in apples and pears, 



2, Substitutes: (l) Any of the standard neutral copper fungicidal 

 powders (for use as summer sprays) indicated above but perhaps with less 

 effectiveness against diseases. Examples; basic copper sulfate (BasiC-op, 

 Tribasic); copper oxychloride (Copper A compound); copper oxychloride sulfate 

 (COCS); and yellow copper oxide (Yellow Cuprocide), To equal the Bordeaux 

 8-8-100 formula, each material should be used in sufficient quantity to 

 give 2 pounds of metallic copper to 100 gallons of water. Note; V(hsn the 

 neutral coppers are used as sumraer sprays on grapes, apples, and pears, 

 an equal amount of hydrated spray lime should be added in order to prevent 

 copper injury to loaves and fruits, (2) Copper dusts are still less 

 effective than neutral copper sprays for summer control, 



VffiTTABLE SULFURS 



1, Physical Charactsristics ; Both the dry wottable powders and paste 

 sulfurs represent the solid, elemental form of sulfur. They form true 

 suspensions in water, 



2, Standard Uses ; Standard summer fungicides for apple scab and 

 black rot; for pear scab and leaf blights; and for brown rot of stone fruits 

 and the leaf bli^^hts of plum and cherry, 



3, Fungicidal Properties ; Strictly preventative, not sradicative, 

 v;hen used on above crops, would be eradicants if applied to red raspberry 

 foliage infected v;ith powdery mildew. Under v;eathor and environni'-;ntal 

 conditions highly favorable for apple scab infections, paste sulfurs have 

 given generally better control than dry wottabl^; p>:iwdors; and the finer 

 particlo sulfurs better contr ^il than coarser particle sulfurs, 



4, Injury , Qompatability ; \Yettable sulfurs may cause "sulfur scald" 

 on apples and pears if present an the fruit during periods of high temper- 

 atures, particularly on the sun-exposed side of the tree, V;"hen combined 

 v/ith lead arsenate, they tend to increase the amount nf arsenical injury 

 on apple foliage and fruit (calj-x-end blackening) if a corrective agent 



such as lime or zinc sulfate and lime is not added. Use of combined wettable 



