FRUIT NOTES - IJIAY, 1941 



W. H. Thies 

 Extension Horticulturist 



Effect of Air Temperatures on Mcintosh Development 



During the last 20 years the date of full bloom of the Mcintosh apple 

 at Amherst has varied from May 3 to 22, or nearly three weeks. The average 

 date of bloom is very near May 14. The duration of bloom has varied from 

 about 3 days to nearly a week. Our dates of harvest are not complete and 

 are not reliable as indicating maturity of the apples. 17e novi pick Mcintosh 

 later than formerly. There is no reason to expect any marked correlation be- 

 tween dates of bloom and of maturity. A little reflection shows why this is 

 true. All plant grovrth and development rests on chemical reactions and obeys 

 the laws of chemical reaction. Within limits the higher the temperature the 

 more speedy the reaction. Y.Tien apple trees bloom early it is because of above 

 average temperatures in early spring. If early bloom is followed by above 

 average temperatures during the growing season, the harvest v/ill be very early; 

 if summer temperatures following early bloom are low, maturity will be near 

 normal. In 1938 Mcintosh v;as in full bloom on May 3 and in 1940 on May 20. 

 The departures from normal temperatures were as follows: 



April May June July August September 



1938 +3.5 -1.5 tl.4 +0.9 +3.8 -2.3 

 1940 -3.6 +0.1 -1.1 -0.2 -1.5 -1.6 



The April departures show why blooming dates were different. '"Je believe that 

 the low summer temperatures in 1940 vrere more effective in causing late ma- 

 turity than the late date of bloom. J. K. Shavj- 



Ringing or Scoring Apple Trees to Hasten Bearing 



About 20 years ago we carried out some experiments at the State College 

 with ringing 8-year-old Viealthy, Oldenburg, and V.'agener trees to hasten bearing. 

 There are two v/ays of carrying out this treatment: (1) Ringing consists of 

 taking out a narrow ring of bark from the trunk or main branch of a tree. This 

 must be rather carefully done. If one wishes to be safe he may tie a sheet of 

 paper around the tree so as to cover the bare ring, though usually this is not 

 necessary. (2) Scoring consists of cutting through the bark of the trunk with 

 a strong knife, making two or three rings, Vidthout removing any of the bark. 

 Either of these processes favors the accumulation of carbohydrates in the top 

 of the tree and frequently promotes fruit bud formation. 



The time of ringing or scoring is important. Inasmuch as fruit bud 

 formation becomes evident in late June or early July, it follows that the op- 

 eration must be performed in late May or early June. Treating trees later is 

 likely to be ineffective and leads to poor yield and weakening of the trees. 

 Treating a tree that has a good to heav^'' crop is not only ineffective in bring- 

 ing about fruit bud formation but also affects tree vigor. Therefore, it offers 

 no promise for promoting annual bearing. Treating trees that are approaching 

 bearing age but have little or no crop is quite likely to be follov/ed by a 

 moderate to heavy crop the next year. It is a special practice for particular 

 conditions and not to be generally recommended. It might be useful on filler 

 trees or where one wishes to get fruit a year or two sooner than he would in 

 the normal course of events. If done at the proper season there is little 

 danger of loss or serious injury to the tree. j. K. Shaw 



