Abstract
Manuring with controlled-release fertilizer was studied to reduce the fertilizer application rate in ‘Miyagawa wase’ unshu over a period of five years. Reduction in the frequency from twice to once at each fertilization, a 20% reduction in the quantity of nitrogen ingredients, and 40–50% reduction in the quantity of phosphoric acid and potassium ingredients had no influence on the tree growth, yield, or fruit quality in wase unshu throughout the experimental period. The results suggest that controlled-release fertilizers can improve the fertilizer efficiency and reduce the labor required reguired for fertilization management in the cultivation of ‘Miyagawa wase’ unshu.
