As mentioned above, the fungicide program 

 in Block C was moderately conservative and, 

 although partly based on hygrothermograph and 

 weather monitoring and spore maturity 

 determination, likely could be improved upon. 

 Fungicide use in Block C largely was driven by a 

 perception that the cost:benefit ratio for 

 fungicide use was low. To eliminate the 

 perceived risk, fungicides were often appUed with 

 insecticides and oil sprays. From a high of 11 

 appUcations and over 9 DE in 1984, fungicide use 

 was reduced in 1987 to the fewest number of 

 spray appUcations (6) and the third fewest number 

 of DE (5.0) since we began record-keeping in 

 1979. This situation was at least partly due to 

 the incorporation of a new sterol-inhibiting (SI) 

 fungicide into the program. 



Aphicide use in Block C was essentially nil, 

 with predators providing control in most years. 

 If needed, Anthony Rossi has been able to 

 coordinate application of endosulfan against aphids 

 and first summer generation adult leafminers. 



Harvest survey results (Table 2). Levels of 

 pest injury in Block C were well within 

 acceptable ranges for commercial orchards in 

 spite of the much lower than average i>esticide 

 program. 



As noted in Table 2, disease injury in all 

 years was negligible, reflecting a consistently 

 successful fungicide program even when less than 

 full rates were used. 



Tarnished plant bug was the most frequent 

 injury found in samples. A high infestation in 

 1983 drove average injury up to 2.4%. However, 

 most of the 1983 injury was of the severity and 

 type that would not have affected fruit grade. 

 In 1983, plum ciu-culio injury reached 1.6%. 



In two years, we experienced late season 

 mite buildup. Red mite eggs in the fruit calyx 

 were observed, although this "injury" is not 

 considered serious by most growers and again 

 should have no effect on grade. 



Table 2. On-tree harvest surveys: percent insect, mite, and disease injury, 

 Horticultural Research Center, 1979-87. 



•TPB, tarnished plant bug; PC, plum curcuUo; EAS, European apple sawfly; 

 AMF, apple maggot fly; ERM, European red mite; BER, blossom end rot; 

 SCAB, apple scab; FS, fly speck. 

 **Eggs in calyx of fruit at harvest. 

 ***Data not available. 



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