Improving the Growth of Newly 

 Planted Apple Trees 



Wesley R. Autio and Duane W. Greene 



Department of Plant & Soil Sciences, University of Massachusetts 



Daniel R. Cooley 



Department of Plant Pathology, University of Massachusetts 



It is well accepted that to be profitable an orchard 

 enterprise must receive returns from new plantings as 

 early in the life of those trees as possible. Rootstocks and 

 cultivars are major factors determining the age at which an 

 orchard begins to pay for itself. Site preparation and 

 cultural practices prior to, during, and after planting also 

 influence the age at which a tree comes into production. 



At the University of Massachusetts Horticultural 

 Research Center in Bclchertown we generally do not 

 obtain a desirable amount of growth the year of planting, 

 and it must be recognized that to obtain early returns and 

 maintain high profitability throughout the life of a block it 

 is necessary for the trees to grow well and produce a good 

 fruiting framework in the years just after planting. Site 

 preparation techniques, such as cover cropping, organic 

 matter incorporation, and installation of irrigation or 

 drainage, are known to improve growth. We decided to 

 study planting and post-planting techniques which may 

 offer some benefit to tree growth. 



Level of Nitrogen Fertilizer 



In 1986 four plantings were established at the Horti- 



cultural Research Center. The first planting (Marshall 

 Mclntosh/M.9) assessed the effects of different levels of 

 nitrogen fertilizer applied soon after planting. It was 

 postulated that additional growth could be obtained if 

 nitrogen was applied at higher rates than usually recom- 

 mended. In 1986 individual trees received either 0.5, 1.0, 

 1.5, or 2.0 pounds of ammonium nitrate in split applica- 

 tions two weeks apart approximately two weeks after 

 planting. Treatments were repeated in 1987; however, the 

 2.0-pound rate was decreased to 1.5 pounds because of 

 tree injury noticed in 1986. Trunk circumference was 

 measured at planting and after the 1986 and 1987 grovving 

 seasons. Total shoot growth was measured after the 1986 

 and 1987 growing seasons. Data are reported in Table 1. 

 In 1986, increasing the amount of ammonium nitrate 

 beyond the standard rate of 0.5 pound decreased trunk and 

 shoot growth. Even in 1987, the second leaf, growth was 

 decreased when the rate of application was increased. We 

 can postulate that root injury occurred in 1986 which 

 carried over to 1987, and that we cannot attempt to 

 improve tree growth with increasing nitrogen applications. 

 Furthermore, these results suggest that we should re- 

 examine our present recommendation of 0.5 pound of 



