Effects of Chemical Fertilization on Brassica pekinensis Tipburn Disease and Yield in Hexi Corridor of Gansu

In order to reduce chemical fertilizers use and increase vegetable quality and yield, adopting dual quadratic rotary combinative design with three factors and five levels, we selected Brassica pekinensis, a major vegetable in HeXi Corridor of Gansu, to conduct a study concerning the relationship between the fertilization and tipburn disease control and production, and a final regression model was established. The results showed that higher N,P₂O₅ or K₂O fertilization was the major factor causing the occurence of tipburn disease increase and production drop for Brassica pekinensis. A reasonable fertilization combination should be as follows:N:420.9 kg·hm^-2~474.7 kg·hm^-2,P₂O₅:155.2 kg·hm^-2~321 kg·hm^-2,K₂O:150.0 kg·hm^-2~160.0 kg·hm^-2; the appropriate N:P₂O₅:K₂O ratio was 1:0.40~0.42:0.30~0.33.