Consideration was given to other diseases in addition to 

 apple scab when choosing fungicides. Most sprays were applied 

 after an apple scab infection had been determined. Intervals 

 between sprays were at least 7 days and fungicides were incorpor- 

 ated with insecticides whenever possible. Occasionally preventa- 

 tive sprays were applied on a management decision basis, rather 

 than a calendar basis. Only fungicides with an adequate kickback 

 action were recommended. 



The end of the primary apple scab season was determined by 

 the end of apple scab ascospore release. Fungicide applications 

 recommended after this time was based on each orchards ' s specific 

 disease problems. In certain orchards, only 1 or 2 fungicide 

 applications, at approximately 1/4 to 1/2 dosage rate, were applied 

 after the primary scab season. Fungicides were no longer applied 

 after infection but rather incorporated with an insecticide or 

 other type sprays. 



Results and Discussion 



The results of 1979 and 1980 IPM programs are compared in 

 Table 1 to demonstrate trends associated with the program. 



Table 1. Cost benefit analysis for fungicide usage and fruit quality 

 on IPM programs in 1979 and 1980. 



1979 1980 



IPM Check IPM Check 



Number of fungicide sprays 10.64 13.00 9.45 10.36 



Dosage equivalents 9.77 11.11 8.11 8.80 



Fungicide cost per acre ($) 74.06 88.68 85.26 94.58 



Percent diseased fruits at harvest 0.99 0.93 0.88 0.90 



Loss to disease per acre ($) 46.28 43.48 50.31 56.30 



IPM net benefit per acre ($) 11.82 15.31 



The reduction in the number of fungicide sprays in the IPM 

 blocks in comparison to Check blocks was 18% and 9% in 1979 and 

 1980, respectively. The amount of fungicide used in the IPM blocks 

 also was reduced by 12% in 1979 and by 8% in 1980. Since the in- 

 cidences of diseased fruit in the IPM and Check blocks were very 

 similar both years, the savings of $11.82 and $15.31 per acre in 

 1979 and 1980, respectively were mainly the result of reduced fungi- 

 cide usage. Savings were greater in 1980 because of inflation even 

 though the reduction in fungicide usage was less than in 1979. 



