HOW TO CONTKOL THE PEAR THRIPS. 



15 



sprayed block and some on the plowed block, but the fruit on the 

 latter continued to drop until picking time. The yield upon the 

 various plats is shown diagrammatically in figure 8, and was as follows: 



Plat A yielded 16,254 pounds of green prunes, or 8,127 pounds of 

 dried prunes, from the 300 trees. This made an average jdeld of 

 5,849.92 pounds of green prunes per acre, or 54.166 pounds per tree. 



Plat B yielded 1,032 pounds of green prunes or 516 pounds of dried 

 prunes from the 98 trees, or an average of 1,138.32 pounds per acre, 

 or 10.54 pounds of green prunes per tree. 



Plat C, consisting of 10 acres, was left untreated to serve as a check 

 for comparison, and yielded 860 pounds of green prunes, or 430 pounds 

 of dried prunes, for the 1,080 trees. This gives an average yield of 

 86.4 pounds per acre, or 0.8 pound of green prunes per tree. 



Fig. 8. — Diagram showing yield per acre in green prunes, Curry orchard, 1910: o. Sprayed and plowed, 

 136.08 boxes, value $190.08 per acre; b, plowed block, 26.46 boxes, value $34.02 per aero; c, check block, 

 2 boxes, value $2.59 x)er acre. (Original.) 



Scahbiness. — An examination and count was made of all the fruit 

 from 5 trees on the sprayed block and from 5 trees in the unsprayed 

 block, giving the following results: 



Total 

 number 

 prunes. 



Number 

 clean. 



Num])er 

 scabby. 



Per cent 



free from 



scab. 



Sprayed block.... 

 Unsprayed block. 



10,139 

 S20 



9.831 

 



308 

 826 



It will be seen from the above table that the sprayed fruit was prac- 

 tically free from scab (the 4 per cent that was scabby being only very 

 slightly marked), while the unsprayed fruit was all badly scabl)ed. 



Size of fruit. — Comparisons of the s])rayed and unsprayed fruit 

 when dried showed the former to average 50 prunes to the pound and 

 the unsprayed 60 to the pound, making a difference of $10 a ton, 

 which would pay nearly half the cost of the spraying. 



Value of the crop. — As all of the values of the prune yields for 1910 

 have been figured on a 5-cent basis for prunes averaging 80 to the 

 pound dried, this basis is heie employed, although the crop was sold 

 for more than the above ((notation and premiums were given for the 

 large size and quality of the fruit. 



