Factors Affecting EBDC Fungicide 

 Residues in Apple Fruit 



Daniel R. Cooley 



Department of Plant Pathology, University of Massachusetts 



Stephen Wood 



New England Fruit Growers' Council on the Environment 



John Schneider 



Very fine Products, Inc., Technical Department 



Apple growers, researchers, and food processors 

 are deeply concerned with the prohlems presented hy 

 the loss of EBDC fungicides. In general, these concerns 

 may he summarized by saying that the loss of the 

 EBDCs as an option will compel growers to use more 

 pesticides in their apple pest management programs 

 (see "Effects of the Loss of EBDC Fungicides on Apple 

 IPM in New England" in this issue). Here we examine 

 the results of a use pattern/residue survey done in 

 1988 in cooperation with a number of New England 

 apple growers. 



The survey was intended as a preliminary study of 

 how use of the EBDCs and captan (and at that time, 



daminozide) might affect residues in apple fruit. Sev- 

 eral growers throughout New England were contacted 

 by the New England Fruit Growers Council on the En- 

 vironment and asked to sample blocks and send infor- 

 mation about those blocks to us. The growers were 

 instructed to sample randomly throughout a given 

 block. Samples were obtained from 28 blocks. The 

 unwashed, raw samples were sent to the Veryfine 

 Technical Laboratory, where they were assigned an ID 

 number. Each block sample was split into two groups, 

 bagged in plastic, and boxed. Half of each sample was 

 then sent to the National Food Processors Laboratoiy 

 in Washington, D.C. for captan/EBDC residue analy- 



Number of 

 Applications 



12 



1 



8 



No residue detected 



Residue detected 



I I I I 



nil i inn i i I ii |i ri 1 1 1 ti 



in i nim i i in lines si 



9 1113 

 Orchard Block 



15 17 19 21 23 25 27 



Figure 1. The number of EBDC applications made for the 1988 season, compared with the EBDC residue 

 on apple samples. Where detectable, the amount of residue increases from left to right; blocks which had 

 no detected residues are represented in the white background, and blocks with a detected residue are in 

 the shaded background. 



22 



Fruit Notes, Winter, 1990 



