azinphosmethyl or phosmet to trees in the eighth 

 interior row and to orchard trees bordering plots on 

 either side. 



Weekly from petal fall until harvest in September, 

 100 fruit m each of rows 1, 3, 5, and 7 of each plot 

 were sampled for mjury by PC and AM. In addition, 

 two unbaited sticky red sphere traps were hung toward 

 the center of each row of each plot to monitor AM. 

 Finally, at harvest, 100 fruit in each of rows 1,3, 5 and 

 7 of each plot were sampled for injury by summer LR 

 and internal Lepidoptera. 



Results 



Incidence of each pest type, as averaged across all 

 samples of fruit or traps in rows I, 3, 5, and 7 of each 

 plot, is given in Table 1. As in 2001, results for 2002 

 show no significant differences among any of the four 

 treatments (all-row versus perimeter-row sprays of 

 Guthion versus Avaunt) in incidence of fruit injury by 

 PC, trap captures of AM, Iruit injury by AM, fruit injury 

 by summer LR, or fruit injury by internal Lepidoptera. 



Injury by PC in 2002 was sufficiently great to 

 justify comparison of PC damage to fruit on perimeter- 

 row trees with damage to fruit on interior trees. 

 Combined date for all-row plus perimeter-row sprays 

 of Guthion revealed that injury to fruit on perimeter- 

 row trees (row 1) averaged about 10 times greater 



(1.275%) than the mean amount of injury to fruit on 

 trees in row 3, 5, and 7 (0.125%). These data suggest 

 that PCs which immigrate into orchards after a petal 

 fall spray has been applied confine their activity to 

 peripheral-row trees and infrequently penetrate into 

 interior rows of orchards. 



Figure 2 displays combined data for each pest for 

 2001 and 2002. All-row sprays of Avaunt were 

 approximately equal to all-row sprays of Guthion in 

 protecting against PC, AM, summer LR and internal 

 Lepidoptera. For both PC and AM, perimeter-row 

 sprays of Guthion performed as well as all-row sprays 

 of Guthion in providing plot-wide control. For PC and 

 especially for AM, perimeter-row sprays of Avaunt 

 were not as effective as all-row sprays of Avaunt in 

 providing plot-wide control. For both summer LR and 

 internal Lepidoptera, perimeter-row sprays were not 

 as effective as all-row sprays in providing plot-wide 

 control in the case of Guthion as well as Avaunt. 



Conclusions 



There were no statistical differences among any 

 of the four treatments evaluated here in ability to 

 control target pests in either 2001 or 2002. Indeed, 

 combined data for both years indicate that all-row 

 sprays of Avaunt were approximately as effective as 

 all-rows sprays of Guthion in ability to confrol PC, 



Table 1 . Effectiveness of Guthion versus Avaunt against pest insects when applied to all rows 

 versus the two perimeter rows of seven-row plots in five commercial apple orchards in 

 Massachusetts in 2002. Values represent data averaged across all samples taken in rows 1, 3, 5 

 and 7 of plots. 



Incidence of pest 



Pest 



Plum curculio (% fhiit with injury)* 

 Apple maggot (no. captured per sphere)* 

 Apple maggot (% fruit with injury)* 

 Summer leafrollers (% fruit with injury)* 

 Internal Lepidoptera (% fruit with injiu^)* 



"No statistically significant differences among treatments at odds of 19: 1 . 



Fruit Notes, Volume 68, Winter, 2003 



