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Effect of doses and location of NPK fertilization on the mineral composition of Jonathan apples

Joanna Szwedo

Department of Pomology
Agricultural University
Leszczyńskiego 58, 20-068 Lublin, Poland

In 1980-1994 Jonathan apple trees on M 4 rootstock were fertilized with varied NPK doses: a low dose of 50 kg N + 25 kg P2O5 + 100 kg K2O) ha-1, a medium one of 100 kg N + 50 kg P2O5 + 200 kg K2O ha-1, and a high dose of 150 kg N + 75 kg P2O5 + 300 kg K2O ha-1. Each dose was applied annually one the entire area of the experimental plots (tree rows and interrows) or only in strips of herbicide fallow in tree rows 1.5 m in width. The sward in the interrows was mown and mulched on the ground. Non-fertilized trees constituted the control. In 1982-1994 the effect of NPK doses and their location on the content of mineral constituents in the apples was investigated. The greatest differences in N, K, and P content occurred between the fertilized treatments and the control, i.e. an increase in N and K content and decrease in that of P were affected by the fertilization, especially by the highest NPK dose. Within the fertilized treatments differences in the content of these constituents in the apples were smaller. The level of Ca and Mg did not depend upon NPK fertilization. The level of N, K, Ca, and Mg in the apples was similarly affected by overall fertilization and by that applied to the strips of herbicide fallow in the tree rows. The content of P was greater in the case of fertilization applied to the tree rows.

Szwedo J., 1996. Effect of doses and location of NPK fertilization on the mineral composition of Jonathan apples. Folia Horticulturae 8/2: 3-11.