230 ANNUAL REPORT OF THE Off. boc. 



FERTILIZATION AND CULTURAL METHODS FOR APPLE 



ORCHARDS 



By TROF. JOHN 1'. STEWAET, Expt. Hort. , State College, Pa. 



It is my purpose to-night to bring before you results which have 

 followed certain orchard treatments in this State and also in others. 



We have not reached our present knowledge of orchard fertiliza- 

 tion by progress in a straight line. At first, apple trees were run 

 on the forest plan. Fertilization Avas not considered. The trees 

 were grown apparently under the impression that their demands 

 were small and their roots were deep and hence were surrounded 

 by virgin fertility and largely inaccessible anyhow to surface appli- 

 cations. 



Then in 1895 came the work of Director Roberts, of Cornell, in 

 v/hich after a chemical study of a couple of trees he concluded that 

 an acre of apple orchard in full bearing annually removes nearly 

 three times (2.94) as much plant food as fifteen bushels of wheat.* 

 Many similar studies followed,! the movement culminating in the 

 extensive reportj of the Geneva Station in 1905, in which the plant 

 food constituents of all the ordinary tree fruits were given. The 

 feeding area has also been found to be comparatively shallow, so 

 that from these studies alone the conclusion was inevitable that 

 a mature-bearing orchard is at least as exhaustive as any ordinary 

 farm crop and hence should be as regularly fertilized. 



Along with the chemical movement, but reported later, came 

 what might be called a preliminary series of field trials. Fertilizers 

 were applied for various purposes, in some cases to improve color, 

 in others for scab, and in a few cases to affect 3'ield. Scab and fer- 

 tilizers were found to be apparently unconnected. Color showed 

 no consistent improvement from either iron sulfate or potash. In 

 one instance, phosphates greatly improved it,§ and nitrates, wher- 

 ever reported, strongly diminished color. On yield and growth, 

 varying results were obtained, the most consistent gains in the 

 earlier experiments being made by nitrogen, || with one improve- 

 ment reported from potash and none from phosphates alone. Most 

 of the experiments comprised but few trees and were of short dura- 

 tion. Their effect, however, in spite of some inconsistencies, was 

 partly to confirm the conclusions of the chemists, at least in re- 

 spect to the necessity for certain elements. 



Then came the reports of the long-time experiments, one in Eng- 

 land at the Woburn Experimental Farm** and another at Geneva, 

 N. Y.ft In them, little effect was observed from the fertilizers 

 applied, and serious doubt was cast on the value of fertilizers in 

 apple-production. 



♦Amount removed in fruit, leaves and wood. Cornell Bui. 103:537-40. Tlie statement la 

 true if the straw is not Included. Including the straw, the relation Is somewhat less than 

 twice (1.93-) the food removed by this amount of wheat. 



tThe results of some of these are presented by Shutt in the Canada Experimental Farms Report, 

 1896, 164: others in Missouri Station Rpt. 1896, P. 77; and bv Browne, Jr., in Penn. Dept. 

 of Agr. Bui. 53. 



JNew York Geneva Station, Bui. 265:220. 1905. 



lExperiment at Wye College, England. 



II Gains are reported from nitrogen in Cornell Bui. 153, in Mass. Bui. 66, and In Maine Bui. 

 139:53. In the Cornell experiment, nitrates applied on August 11, 1894 are reported to have 

 failed to show important effects until the season of 1896, although the ground was tilled. 



♦♦Reported in 1900. 



tfNew York Geneva Bui. 289. 1907. Nitrogen not applied. 



