SPBAYING 27 



SPRAYING 



27. Blight, rot, and scab are fungous diseases of orchards 

 which decrease the yield and quality of the fruit grown. 

 Bordeaux mixture is used for killing fungous growths, such 

 as black rot and scab of apples. To make a solution for 

 spraying, dissolve 4 Ib. of freshly slaked lime and 4 Ib. of 

 copper sulphate in 50 gal. of water. If chewing insects that 

 destroy plants by eating the leaves are also to be destroyed, 

 add J Ib. of Paris green or 3 Ib. of arsenate of lead paste to 

 the Bordeaux mixture. A sufficient amount to spray one 

 tree is 2^- gal. 



28. A Paris-green solution, consisting of Ib. of Paris 

 green mixed with 50 gal. of water, is used to destroy insects 

 that chew the leaves of potatoes. 



EXERCISE 



1. In the spring of 1910 the Kentucky Experiment 

 Station took as a subject for demonstration an orchard in 

 Hardin County which had never been sprayed. A single 

 row of trees extending through the orchard was sprayed 

 twice with Bordeaux mixture, once immediately following 

 the blooming period, and again 12 da. later. One sprayed 

 Maiden Blush tree yielded 7 bu. of apples, 4J bu. of which 

 graded " firsts," the remainder " seconds." One unsprayed 

 tree of the same variety in the next row yielded 4 bu. of 

 apples, \ bu. of which graded firsts. When firsts were 

 selling at 800 a bushel and seconds at 400, what was the 

 difference in the market value of the fruit grown on the 

 two trees ? 



2. When the yield and the quality of the fruit in the 

 above problem is an average for sprayed and unsprayed 

 trees, what will be the difference in yield in two orchards 



