Studies on the foliar sprays of nutrient elements in apple trees

Abstract

Field and pot experiments were carried out during 1953_??_1958 to ascertain whether phosphate, potash and a foliar fertilizer containing nitrogen, phosphorus and potassium could be absorbed through apple leaves by foliage spray. The principal results obtained are summarized as follows. (1) Apple trees were able to absorb phosphorus and potassium through leaves by foliage spray of 0. 5 per cent mono-ammonium phosphate solution and of 0.5_??_1.6 per cent potassium sulphate solution. (2) Nitrogen, phosphorus and potassium in the foliage fertilizer could be absorbed through apple leaves by foliar spray. As to nitrogen and phosphorus in the foliage fertilizer, absorption began five hours after the spraying and as for potassium it was ten hours. (3) Sprays of the foliar fertilizer during middle in May to late in August increased the growth of young apple trees. (4) Sprays of the foliar fertilizer during middle in May to late in August reinvigorated an extremely weakened apple trees injured by the root. rot (Rosellinia necatrix and Helicobasidium mompa TANAKA)and suffered from the potassium deficiency. (5) The concentration of the foliage fertilizer for practical use to apple trees was 0.2 to 0.4 per cent. Spray solution of the foliar fertilizer mixed with lime sulphur caused burning of leaves, however, any burning of leaves, did not occurred mixing of the foliar fertilizer with Bordeaux mixture or with lime sulphur added ferric sulphate.