Effect of potash on yield and quality of apple trees in Shaanxi province

IPNI-1997-CHN-SN3

28 May 2001

1998 Annual Interpretive Summary


The effects of potassium application on yield and quality of the main fruit trees in Shaanxi province, 1998

Inadequate K supply is limiting both the yield and quality of agricultural products in Shaanxi. This is especially observed in fruit trees. In 1997, 715,333 ha of fruit trees were planted...602,667 to apple, 60,000 to pear and 15,333 to kiwi fruit. The ratio of fertilizer N-P2O5-K2O consumption in Shaanxi province is currently unbalanced at 1-0.25-0.08. In 1997 and 1998, three fixed site trials on apple, one on pear, and one on kiwi fruit compared different varieties and rates of K fertilizer while using the same N and P rates. Potash applications of 260 to 1,494 kg K2O/ha (0.6 to 1.2 kg K2O/tree) increased yields of Fuji apple, Qingguan apple, pear, and kiwi fruit by 5.5 to 30.2, 18.5 to 26.3, 21.4 to 25.5, and -2.2 to 52.2 percent, respectively. Potash application also improved internal and external fruit quality and regulated tree vegetative and reproductive growth. Potassium chloride plus S was the first choice for apple and pear, while K2SO4 was the best source for K and S in kiwi fruit. The KCl significantly reduced the incidence of disease-infected fruit, especially black-spot disease of pear. The potential for large increases in K consumption in Shaanxi is very positive. SHAANXI-03