■10- 



processes based on levels of pest populations as determined by the 

 above techniques will be forthcoming in a future issue of Fruit 

 Notes . ) 



Fruit injury at harvest was determined in each IPM and check 

 block on the basis of on-tree surveys of 800-2200 fruit per block 

 (100 fruit per tree from each of 2 trees adjacent to trapping 

 stations). In addition, we sampled at harvest fruit injury from 

 another block in each IPM orchard of similar tree size and varietal 

 composition. Injury in these blocks was determined by on-tree sur- 

 veys of 1000 fruit per block (100 fruit per tree from trees randomly 

 located within the block) . 



Results 



Fruit Injury . Injury at harvest was divided into 2 categories: 

 (a) permanent damage to the skin or flesh of the fruit; and (b) 

 damage to the skin which could be removed by washing (i.e., woolly 

 apple aphids (WAA) in the stem cavity, sooty mold (SM) , or white 

 apple leafhopper (WAL) excrement) . 



Overall, permanent damage was 6% less in IPM blocks than in 

 same orchard non-IPM blocks, and 23°o less than in check blocks 

 (Table 1). Removable injury was 95% less in IPM blocks than in 

 same orchard non-IPM and 93% less than in check blocks. 



Specifically, as in 1978, TPB was the most damaging fruit pest 

 in Massachusetts commercial apple orchards, with IPM blocks averag- 

 ing slightly less injury than check or same orchard non-IPM blocks. 

 We believe that this reduction in TPB fruit injury in IPM blocks was 

 due to better timing of spray applications rather than differences 

 in pest pressure, since trap captures of TPB were nearly identical 

 (13.3 per trap in IPM blocks vs. 13.6 per trap in check blocks). 

 We attempted to develop a TPB damage grading index so as to determine 

 how much of this TPB injury would result in down-grading of fruit 

 value. Preliminary indications are that 321 of TPB injury would 

 grade through as U.S. Fancy fruit, 52% would grade U.S. #1 and 16% 

 would be culled. We plan to continue this work in 1980. 



Fruit injury as well as trap captures of EAS were down substan- 

 tially from 1978, with virtually no difference between IPM and check 

 blocks. Plum curculio (PC) injury was about the same as in 1978. 

 Injury from PC was higher in IPM than check blocks due mainly to 

 substantial injury (1.6%) in one orchard. San Jose Scale injury to 

 fruit was considerably less in IPM than check blocks, where, as in 

 1978, scale was the second most damaging pest. Apple maggot fly 

 (AMF) captures were down substantially from 1978, perhaps due to 

 interference of dry weather with fly emergence from pupae. Trap 

 captures were slightly higher in check blocks, as was injury at 

 harvest from this pest. First captures of AMF in an abandoned or- 

 chard in Northboro, MA occurred the week of June 1, while first 

 captures in a commercial orchard occurred July 12. This difference 



