-15- 



Number of fungicide sprays varied from 8 to 14 among the 

 IPM orchards, witli dosage equivalents ranging from 7,95 to 

 11.68 (Table 2). The lower number of fungicide sprays and 

 dosage equivalents were due to efficient timing of fungicide 

 applications aimed especially at apple scab. (Fungicides were 



Table .3. Cost benefit analysis of fungicide usage and fruit quality 

 for control orchards in the IPM program in 1981. 



Orchard Number Dosage Control orchards 



of Equiv. % diseased Fungicide $ loss to 



fungicide- fruits at cost per disease 



sprays harvest acre per acre 



applied as protective sprays just prior to predicted long wetting 

 periods while sprays were withheld prior to predicted shorter wet- 

 ting periods, applying kickback sprays only when wetting periods 

 and temperature suggested infection periods--as measured by hygro- 

 thermographs .) Increased number of fungicide applications', without 



Table 4. Cost benefit analysis of fungicide usage and fruit quality 

 for IPM programs 1978 through 1981. 



1978 1979 1980 1981 



IPH' Control IPM Control IPM' Control IPM Control 



No. /fungicide 



sprays 11.80 12.5 10.64 13.00 9.45 10.36 11.00 13.00 



Dosage 



equiv. 12.04 12.18 9.77 11.11 8.11 8.80 9.63 12.04 



Fungicide cost/ 



acre ($) -^ - 74. 06 88.68 85.26 94.58 106.72 140.00 



% diseased 



fruits at 



harvest 3.45 1.32 0.99 0.93 0.85 0.40 0.77 0.20 



Loss to disease/ 



acre ($) - - 46.28 43.48 50.31 56.30 35.28 9.79 



IPM benefits per acre ($) 11.82 15.31 7.79 



— — . . _, _ _ 



Data not taken. 



