APPLE ROOTSTOCK STUDIES 



William J. Lord 

 Department of Plant and Soil Sciences 



Recently, A. P. Preston, East Mailing Research Station, Kent, Eng- 

 land, published the results of 15 years' experience with apple trees on 

 all the Malling-Merton (M«M,) clones and Mailing (M.) XXV, and compared 

 their performance with trees on older clonal rootstocks (The Journal of 

 Horticultural Science M-1 (No. 4) :3M-9-3 60, October, 1966). These trials 

 showed that none of the trees on the new clones were as small as those 

 on M.IX. Trees on M.M.106 and M.VII were similar to each other in size 

 and cropping but unlike M.VII, M.M.106, was free from suckering. M.M.lll 

 and M.II made trees of similar size, but Cox on M.M.lll yielded 20% more 

 fruit than on M.II over the 15-year period of the trial; this was not 

 solely an effect of earlier bearing for the difference in yield persisted 

 through years 11 to 15. Trees on M.M.IOM- were larger than those on M.II 

 and M.M.lll were heavy -bearing. 



No large differences in fruit size between trees on different root- 

 stock occurred and in some instances fruit size on the same rootstock 

 varied greatly for different varieties and different soils. This indi- 

 cates that rootstock is not one of the major factors affecting fruit 

 size. Preston pointed out, however, that among the most fruitful root- 

 stocks, trees on M.IX, M.VII, M.II, M.XXV, M.M.106 and M.M.lll all pro- 

 duced relatively large fruits. On the other hand, fruits from the heavy- 

 yielding trees on M.M.104 were smaller than those from trees on M.IX. 

 Fruit from trees on M.M.lll were not smaller than those from M.II, even 

 though yields were higher on M.M.lll. 



Fruit color was recorded and showed only small differences betv\'een 

 rootstocks . 



(M.VII is the common size-controlling rootstock in our orchards at 

 present. A few growers have trees on M.II, but most favor M.VII, because 

 trees may be smaller on this rootstock. There is interest in M.M.106, 

 since it is free of suckering and also it is reported that trees on this 

 rootstock are better anchored than those on M.VII. Editors) 



*************** 



POMOLOGICAL PARAGRAPH 



Paying Apple Pickers by the Bucket . An apple harvest procedure new to 

 the Extension Pomologist, but in use in Appalachia, is that of paying 

 pickers by the bucket rather than by the bulk box. A picking crew which 

 may consist of 10 to 12 men, empty full picking buckets into the same 

 bulk box, A checker, who stands by the box, records the buckets harves- 

 ted by each crew member and also examines the fruit for excessive physi- 

 cal damage. This harvest procedure has merit because the consolidation 

 of the crew simplifies management. 



