4 - 



in the spring. or by failing to apply N by mid-April. These 

 symptoms were present in many of our peach orchards in May and 

 early June of 1977. Some growers asked if urea sprays would bene- 

 fit growth. Unfortunately, foliar sprays of N to peach trees are 

 ineffective. Peach leaves do not absorb N as efficiently as do 

 apple leaves. 



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



FACTORS AFFECTING SHAPE OF APPLES 

 AND INCREASING THEIR LENGTH WITH PROMALIN* 



W.J. Lord and Duane Greene 

 Department of Plant and Soil Sciences 



Shape of apples is known to be influenced by both climatic and 

 non-climatic factors. The elongated shape and the 5 lobes at the 

 calyx end of Delicious apples are particularly distinctive; thus, 

 there is interest in studying the factors influencing their shape 

 and the possibility of modifying that shape by chemical means. 



Climatic Factors 



Delicious grown in Massachusetts are longer some years than 

 others and within a given year their shape will vary considerably 

 among orchards. Shape of apples depends on cell division and 

 cell elongation, both of which occur within 3 to 4 weeks after 

 bloom, and is governed by growth hormones in the tree. 



In 1914 J. R. Shaw in Massachusetts reported on the relationship 

 between shape of Ben Davis and Baldwin apples and the temperature 

 following bloom; the cooler the temperature, the more elongated 

 the apple. He concluded that during the post-bloom period, temper- 

 ature variations between the 6th and 16th day after full bloom 

 fitted the observed variations in shape more closely than during 

 any other period. 



Non-climatic Factors 



As most growers know, distribution of seeds in fruit influences 

 shape. Apples with small numbers of seeds are frequently lopsided, 

 with the less fleshy side being the one lacking seeds. M.N. 

 Westwood and L.T. Blaney, in Oregon, found that rootstocks, crop 

 density, cluster position, and strain can also influence fruit shape 

 (Non-climatic factors affecting the shape of apple fruits. Nature 

 200:802-803, 1963). In studies with Delicious, fruit from trees 

 on M.l, M.2, M.16 and seedling roots were longer than those harvested 

 from trees on M.9, M.4 and M.7. Both crop load and fruit location 

 affected the shape of Golden Delicious. Those from trees with a 

 light crop (whether the result of heavy thinning or light bloom) 

 were longer than fruit from trees with a heavy crop. The "king" 

 fruit were longer than side-bloom fruit. Fruit shape differed 

 significantly among the 3 Delicious strains studied, with those 

 from the "regular" Delicious trees being flatter than those from 



*Trade Name 



