APPLE LEAF AND WEED COMPOSITION DEOENDING ON FERTILISATION

The contents of N, P, K, Mg and Ca in apple leaves, in leaves of Taraxacum officinale and in the total aerial part (stem with leaves) of Erigeron canadensis were compared in the years 1989–1994. ‘Jonathan’ apple trees on M.4 rootstock were planted in 1970. Starting from 1980, different NPK fertilisation was applied, either on entire plots or on herbicide strips or grassed alleyways only.
The following annual doses, in kg.ha¹, were used: (1) N-50, K₂O-100, P₂O₅-25; (2) N-100, K₂O-200, P₂O₅-50 and (3)N-150, K₂O-300, P₂O₅-75. In factorial design, with 3 modes of application, they composed 9 treatments.
The 10th treatment was a non-fertilised check, T. officinale leaves were sampled from alleyways,E. canadensis stems from herbicide strips.
In N content, a close relationship was found between all three plants under study and in P, Mg and Ca concentration between apple leaves and dandelion leaves when all ten treatment were compared.
Less pronounced was the relationship between the composition of E. canadensis aerial parts and apple leaves as well as in case of K in all three plants.
The concentration of P and Mg decreased with increasing doses of NPK, in all plants.
The content of N and K showed an opposite trend, especially in weeds.
With increasing doses of NPK, Ca content decreased in weed tissues but not in apple leaves.
The results of weed analysis may serve as additional source of information about the nutritional status of an orchard, particularly for Ca.
However, weed composition may be altered by local conditions.

III International Symposium on Mineral Nutrition of Deciduous Fruit Trees

J. Lipecki

https://doi.org/10.17660/ActaHortic.1997.448.94