-14 



On the basis of these results, we've calculated (see Table 2) 

 that with the average reduction in number of insecticide applications 

 (3) in the IPM orchards, these growers saved between $173.70 and 

 $322.50 (depending on material and rate) on insecticides alone in 

 each 10-acre IPM block. 



TABLE 2. Savings Attributable 

 IPM Orchards for the 

 Comparisons Based on 



to Decreased Insecticide Usage in 

 Two Most Commonly Used Materials. 

 3 Applications Saved. 



Chemical Cost^/Lb. Rate/100 Gal. Savings/A^ 



Savings/10-A Block 

 1 Applic. 3 Applic, 



Guthion 

 Imidan 



$4.30 

 $1.93 



1/2 lb. 



5/8 lb. 



3/4 lb. 



1 lb. 



1-1/4 lb. 



$ 8.60 

 10.75 



5.79 

 7.72 

 9.65 



$ 86.00 

 107.50 



57.90 

 77.20 

 96.50 



$258.00 

 322.50 



173.70 

 231.60 

 289.50 



Does not include aphicide use, costs of labor, gasoline or equip- 

 ment . 



^ Costante, J. 1978. Insecticide guide for control of major pests 

 and cost comparison. Univ. of VT (mimeo) . 



X 



Based on 400 gal. /A dilute for IPM orchards 



Table 3 gives a list of the major apple- infesting pests. This 

 list was based on an on-tree harvest survey of 2,000 fruits per 

 orchard (100 fruits per tree on each of 20 trees) . In both the IPM 

 and check orchards, TPB accounted for the greatest percentage of fruit 

 injury. (However, we found no good relation between TPB trap captures 

 and TPB injury levels at harvest.) In the IPM orchards, EAS ranked 

 second in terms of injury level. (We found that EAS trap captures 

 and EAS injury levels are highly related, and for this reason we will 

 be able to even more accurately time and predict need for insecticide 

 applications aimed against EAS next year.) In the check orchards, 

 San Jose' scale and green fruitworms caused more injury than EAS and 

 other pests except plum curculio. We attribute better control of GFW 

 in the IPM orchards to our careful monitoring of the presence of the 

 larvae. In the IPM orchards, we attribute the excellent control of 

 AMP with minimum insecticide usage to the information obtained from 

 AMF captures on the unbaited spheres. Captures of AMP on these 

 spheres were considerably greater and much better related with AMF 

 injury to fruit at harvest than were captures on the baited spheres 

 on Zoecon yellow rectangles. In one IPM orchard, no mature female 

 AMF were captured until August 14, and few CM were captured. Based 

 on our recommendations stemming from these trap captures, no insecti- 

 cide was applied between June 6 and August 16. The result: no fruit 

 injury whatsoever from AMF, CM, or any other fruit pest except early 

 season TPB. We found almost no codling moth and leafroller injury 

 on fruits at harvest in any of the other orchards. 



