INFLUENCE OK 81»RAYS ON THE FRUITING OF THE TREES. 115 



COMrAKATIVE VALUE i)F 81'UAVS IN ItELA'IlON To KKIII. 

 (Pl«. XIII, XIV, und XV.) 



A review of tlic preceding table will .show that no account ha.s been 

 taken there of the peaches thinned from the trees, and for this reason 

 the results given in dollars and cents for the ditt'erent rows can not be 

 taken as representing the full coniiMU'ative value of the sprays us(^d. 

 The value of a spray in controlling curl, so far as (juantity of fruit is 

 concerned, should be l)ased upon its power to prevent the fall <jr loss 

 of fruit from th(! disease. A spray may enable a tree to set more 

 fruit than it can carr}'^ to maturity in a favorable season, but the value 

 of the spray should not be decided from the amount of the crop aft<^r 

 (binning. This will be evident from a consideration of the fact that 

 in many years the trees may not set more [x-aches than can be propyrly 

 matured without thinr)ing. In such cases it would be the .spray that 

 enabled the trees to set and hold the greatest number of peaches in 

 the i>resence of curl which would jjrove of the highest value to the 

 grower. A le.ss effective spray W(jul(l not enable the trees to set and 

 hold a full crop. It is thus seen that the comparative value of .several 

 sprays rests in th(Mr power to prevent the fall of the greatest num- 

 ber of peaches from di.sea.se, this being, of course, where other influ- 

 ences of th(^ spiays are equal. Thinning is nece.s.sary only when the 

 trees can not carry all the fruit .set, or when it is desired to improve the 

 size and quality of the fruit, and it bears no direct relation to the 

 value of a .spray in preventing curl. 



In view of the preceding facts, a table has been prepared embodying 

 tho.se features of the fruit records by which the comparative value (;f all 

 the sprays used may be determined. 



To show the full comparative value of all influences of each .spray 

 upon the fruit, it has also been necessary to consider the quality as 

 well as the number of peaches and weight of Same. To obtain the 

 ultimate comparative value of the sprays the writer has been obliged 

 to treat the thinned peaches as if matured, a.ssigning them the .same 

 value, in proportion to number, as the matured fruit. There is also 

 one other calculation in the table which requires explanation. A con- 

 siderable percentage of the better (piality of fruit was picked while 

 .still immature. This fruit is tabulated as that for the Oakland can- 

 nery. It was noce.s.sary to gather this fruit while still hard so that it 

 would arrive at the Oakland cannery in good condition. By weighing 

 a large number of matured peaches and an equal number of peaches 

 as picked for the Oakland cannery it was learned that the Oakland 

 fruit should be increased by 11 per cent to make it equal in weight to 

 mature fruit. This has been done, so that the quantity, quality, and 

 full comparative value of all fruit considered could be accurately 

 determined. 



