苹果本世纪30年代,Overly等(1931)就开始研究钾肥对苹果品质的影响。他们发现钾和氮能减少贮藏中的腐烂,因而延长了货架寿命。密执安的科学家也发现,含钾低总是与果肉腐败相联系。然而,当钾素营养在苹果生长期保持在最适范围内,对果实的贮藏品质看不出有明显的影响。Drake等(1970)研究了叶片中的氮/钾比与果实着色的关系。在高氮条件下,果 Apple In the 1930s, Overly et al. (1931) began to study the effect of potash on apple quality. They found that potassium and nitrogen reduce decay in storage, thus extending shelf life. Michigan scientists also found that low potassium is always associated with flesh corruption. However, when potassium nutrition is kept within the optimal range during apple growth, there is no obvious effect on the storage quality of the fruit. Drake et al. (1970) studied the relationship between leaf nitrogen / potassium ratio and fruit coloration. Under high nitrogen conditions, fruit