31 



$17.64/A in Previous -Year IPM blocks, and $3.25/A in First-Year 

 IPM blocks. 



It is interesting to note that in 1982, the most favorable 

 cost/benefit ratio existed in 15 1001 Cooperator IPM blocks. While 

 the cost of oil, miticide and aphicide sprays was greater in such 

 blocks compared to the checks, substantial per-acre savings in 

 insecticide materials and application costs, combined with a slight 

 reduction in the value of fruit lost due to insect injury, resulted 

 in an average net benefit from IPM of $56.95 per acre. 



This finding may illustrate the potential value to growers 

 from complete rather than partial implementation of an IPM system. 

 This is particularly true with regard to the use of reduced pesti- 

 cide rates and the need for cooperation between pest manager and 

 grower to insure optimal spray timing. This latter factor is of 

 particular significance inasmuch as IPM spray decisions frequently 

 are made when pest levels have reached an action threshold level. 

 Substantial delays in spray application beyond this point may 

 result in higher levels of injury than if growers had followed a 

 traditional preventative program. 



Pesticide use, insect injury and cost benefit analysis, 1978-1982 . 

 Figure la details trends in dosage equivalents of insecticide 

 used in IPM vs. check blocks since the inception of the Apple IPM 

 pilot program. Check insecticide use remained near the level used 

 prior to IPM program initiation while cooperating IPM blocks have 

 experience an overall 26% reduction in insecticide DE used. Similar 

 results are evident in Figure lb, detailing miticide DE used from 

 1978-1982. In this case, IPM blocks have used an average of 54% 

 fewer such materials than check blocks. 



Fruit injury at harvest was lower in IPM blocks in 3 out of 5 

 years in spite of lower pesticide use, averaging 13°6 less fruit 

 injury than checks. 



Table 6 contains results of cost benefit comparisons performed 

 from 1978-1982. Data from 1980 to 1982 are subsets of all IPM blocks 

 which account for degree of cooperation with specialist recommenda- 

 tions, a parameter which may strongly influence program results. 



Over the 5 year span of the pilot program, highly cooperative 

 IPM growers realized an average net benefit of about $82.00 per 

 acre, exclusive of scouting costs. Private scout consultants 

 presently are offering IPM services to growers for $20-$30 per acre, 

 indicating a potential savings to growers for continued IPM effort. 

 Growers who plan to perform their own scouting will be able to save 

 even this scout/consultant fee and should be able to realize a more 

 favorable net benefit. 



