trees. Select a twig near the periphery of the tree and 

 mark it with piece of flagging. Beginning at this point, 

 walk slowly around the tree counting all flower clusters 

 within the browsing zone (i.e., below the flagging on 

 trunk). Then repeat the count for all clusters above the 

 browsing zone. (Counts of flower clusters take about 

 10 minutes per tree.) 



5. Determine the percentage of tree within the 

 browsing zone as: 



clusters of flowers within zone / (flower clusters 

 within + flower clusters above browsing zone) 



Determine the mean for all trees combined. 



6. Determine harvest and net value of crop. In Fall, 

 immediately after harvest, record the total number of 

 bushels of apples produced and the average selling 

 price per bushel (minus any costs for picking, storage, 

 or transportation). 



7. To determine impact of depredation: 



a. Multiply the number of bushels harvested by 

 the percentage of flower clusters within the browsing 

 zone. This calculation will give the number of bushels 

 produced within the browsing zone. 



b. The number of bushels that would have been 

 harvested within the browsing zone if depredation had 

 not occurred can be determined using the relationship 

 between percentage of buds removed to percentage of 



first crop lost following depredation. This can be 

 calculated as: 



bushels harvested within browsing zone 



[(100-% bud removal) x 100] 



c. Determine bushels of harvest lost by subtract- 

 ing potential harvest before browsing from the actual 

 harvest within the browsing zone. 



The procedure for determining losses in young 

 orchards (1 to 5 years old) is similar to that for mature 

 orchards except that bud counts are made over the 

 entire tree rather than on selected branches, because 

 the entire tree is accessible to deer for browsing. 



Final Note 



Although there is some evidence suggesting that 

 overall tree vigor and potential fruit production may be 

 negatively impacted for several years following initial 

 depredation, these researchers stressed that their 

 method of assessi ng deer browsing impact is applicable 

 only to the first crop following depredation. They could 

 not separate the effects of other confounding factors 

 (seasonal variability within trees, differences in annual 

 weather conditions, etc.) from the effects of depreda- 

 tion when they tried assessing impact on potential 

 production in subsequent years. Research is continu- 

 ing on this aspect of the problem. 



Fruit Notes, Summer, 1990 



25 



