苹果幼园连续多年间作甘薯易出现缺钾症我们对卢龙县连续４—７年间作甘薯的３０个长富２苹果幼园调查看出，这些果园的苹果幼树均有不同程度地缺钾症。轻度缺钾的长富２苹果幼树，表现新梢较短、较细，新梢中部和中下部叶片变成黄色逐渐向顶部和基部叶片发展，开花较少，... Apple kindergarten for many years for many years prone to potassium deficiency potassium deficiency we Lulong County for 4 to 7 consecutive years as a sweet potato 30 Chang Fu 2 apple seedlings survey found that these young apple trees have different levels of potassium deficiency potassium disease. Slightly potassium-deficient Chang-Fu 2 apple young trees, the performance of shoots shorter, thinner, middle and lower shoots of young shoots turn yellow gradually to the top and base leaf development, flowering less, ...