Improving the Growth of Newly Planted Apple Trees

Abstract

Increasing the N application rate (in the form NH 4 NO 3 to newly planted `Marshall McIntosh'/M.9 apple (Malus domestica, Borkh.) trees beyond 76 g N per tree per year reduced growth in the first two growing seasons. Peat moss or composted manure mixed into the planting hole of `Royal Gala'/M.26 increased growth in the first growing season after planting. The soil-active fungicides, fosetyl-Al and metalaxyl, increased trunk and shoot growth of `Royal Gala'/M.26 in the first season after planting. Mulching enhanced growth of `Gala'/M.26 only in the third season after planting, a season during which the region experienced a drought. Mulching significantly increased bloom on `Gala'/M.26 2 years after planting. The growth of `Royal Gala'/M.26, `Marshall McIntosh'/M.26, and `Ace Delicious'/M.26 was not affected by planting technique planting by hand in 61-cm augered holes vs. planting with a mechanical tree planter. Chemical names used N-(2,6-dimethyl-phenyl)-N-(methloxyacetyl)alanine methyl ester (metalaxyl); aluminum tris (O-ethyl phosphonate) (fosetyl-Al); 1,1'-dimethyl-4-4'-bipyridinium ion (paraquat); isopropylamine salt of N-(phosphonomethyl) glycine (glyphosate).