treatment beneath the canopy and mowing grass in the 

 alleyway kept understory growth from reachmg any 

 branches. These measures insured that PCs could gam 

 entry into the canopy only by crawling up the tree trunk 

 or by flight into the canopy. 



On April 18 at the tight cluster stage of bud 

 development, a band of white cloth 3 inches wide was 

 wrapped tightly around the trunk of each of seven 

 Mcintosh and seven Red Delicious trees at a height of 

 12 inches above ground. The cloth was firmly stapled 

 to the trunk, after which the cloth was coated with a 

 thick layer of Tangletrap, 2 inches wide. The Tangletrap 

 was maintained free of debris for the duration of the 

 PC season. Adjacent to each Tangletrap-banded tree 

 was a check tree of like cultivar, devoid of Tangletrap. 



Weekly beginning one week after petal fall (May 

 15) and ending when fruit reached 1 inch diameter 

 (June 10), ten fruit were sampled on each of the 14 

 Tangletrap-banded and 14 check trees for presence or 

 absence of PC egglaying scars. 



Results 



Results (Figure 1) show that very little fruit injury 

 occurred on either Tangletrap-banded or non-banded 

 apple trees during the first and second weeks after petal 



fall. By the third week, when fruit averaged about 1/2- 

 inch diameter, there were slightly fewer injured fruit 

 on banded than non-banded trees. The weather was 

 unusually cool and damp during the first 3 weeks after 

 petal fall. During the fourth and fifth weeks after petal 

 fall, temperatures warmed and injury to fruit by PC 

 increased substantially on both banded and non-banded 

 trees. By the fifth week, there was essentially no 

 difference in percent injured fruit on banded and non- 

 banded trees. 



Conclusions 



Findings from this experiment are in agreement 

 with findings of our previous studies. In cool weather, 

 PCs tend to enter tree canopies primarily by crawling 

 up tree trunks. Under such conditions, a band of 

 Tangletrap around the tree trunk can aid (at least 

 slightly) in reducing the number of PCs entering the 

 canopy and thereby reduce damage to fruit. In warm 

 weather, PCs tend to enter tree canopies primarily by 

 flight. Under such conditions, which are the most 

 favorable of all for PC egglaying, a band of Tangletrap 

 around the tree trunk is of little or no help in preventing 

 PC entry into the canopy and hence of little or no help 

 in preventing damage to fiaiit. 



it it it it it 



14 



Fruit Notes, Volume 68, Winter, 2003 



