10 



EXPERIMENT STATION BULLETIN 



number of sprays are related and the conclusions are similar. The per- 

 centage of farms having unsatisfactory control was greater in the group 

 with small application of spray material. The data in Figure 6 indicate 

 the position of individual orchards as to gallons of spray and control 

 ratings 4 . 



Amount of calyx spray and control 



Since all operators apply the calyx to all trees every season, the 

 amount of spray applied at this time is thought to be a good measure of 

 the practice on each farm as to the amount of material applied in one 

 spray application. Seventeen operators applied five gallons or less per 

 mature-tree equivalent, 15 applied between six and 10 gallons, and eight 

 used more than 10 gallons. Forty-seven per cent of those applying less 

 than five gallons, 40 per cent of those applying between six and 10 gal- 

 lons, and none of those applying more than 10 gallons had unsatisfactory 

 control. However, three orchardists applying less than five gallons ob- 

 tained excellent control. On the other hand, six of those applying be- 

 tween six and 10 gallons had unsatisfactory control. In Figure 7 the po- 

 sition of individual farms with respect to amount of calyx applied and 

 control ratings is indicated 5 . 



NUMBER OF ORCHARDS 



14 

 12 

 10 



8 



6 



~m 



8 



PER CENT OF ORCHARDS 



100 



80 



60 



40 



CONTROL 

 I VERY GOOD 

 [GOOD 



[unsatisfactory 



20 



20 

 40 

 60 

 80 



1 



I 



1= LESS THAN 5 SPRAYS, LESS THAN 10 GALLONS CALYX SPRAY USED 

 2- 5 OR MORE SPRAYS, LESS THAN 10 GALLONS CALYX SPRAY USED 

 3=- 5 OR MORE SPRAYS, 10 OR MORE GALLONS CALYX SPRAY USED 



Figure 8. — Control ratings of 40 orchards applying varying numbers 

 of sprays and varying amounts of calyx spray per season 



4 The coefficient of correlation between gallons of spray applied per mature-tree equivalent dur- 

 ing the season and control ratings is: r — .57. 



5 The coefficient of correlation between gallons of calyx spray per mature-tree equivalent and 

 control ratings is: — .54. 



