Abstract:

【Objective】 To enhance the ability of walnut to resist leaf scorch disease by taking the regulation of tree nutrient level as the entry point in the hope of providing a theoretical basis for the scientific prevention and control of the disease.【Methods】 The changes of mineral elements in healthy, mild, moderate and severe walnut leaf scorch disease production gardens and walnut leaf leaves after different fertilization treatments were systematically compared.【Results】 Differences in leaf mineral element contents in walnuts with different pathogenesis levels were compared.In terms of a large number of elements, the contents of N, P, K and Ca in the leaves of healthy garden were significantly higher than those in medium garden and heavy garden (P<0.05); The Mg content in the leaves of the healthy garden was significantly lower than that in the diseased garden (P<0.05); In terms of trace elements, the contents of Fe, Mn and Cu in the leaves of the healthy garden were significantly higher than those in the morbidity garden (P<0.05); The contents of Cl, Na and Zn were significantly lower than those in the morbidity garden (P<0.05); The contents of Na and Cl in healthy soil were significantly lower than those in moderate and heavy gardens (P<0.05); Principal component analysis revealed that N and K were positive in PC1 and PC2 so they were positively correlated, which played a major role in focal leaf scorch.After fertilization treatment, the combination of reasonable root application N, K and leaf spraying N and K was the best, the incidence rate of which was reduced to 8%, and the nitrogen and potassium content in soil and leaves increased significantly.【Conclusion】 The occurrence of walnut leaf scorched is closely related to low content of N and K and high content of Cl, and reasonable supplementation of N and K can effectively prevent and control walnut leaf scorch disease.

Key words: walnut; leaf scorch disease; mineral elements; fertilization

摘要：

【目的】分析树体营养水平调控增强核桃抗焦叶病能力,为核桃焦叶病科学防控提供理论依据。【方法】通过系统比较健康、轻度、中度、重度核桃焦叶病生产园以及不同施肥处理后核桃样园和核桃叶片中矿质元素含量变化。【结果】核桃不同发病程度叶片矿质元素含量之间差异比较:大量元素为健康园叶片中N、P、K、Ca含量显著高于中度园和重度园(P<0.05),而健康园叶片中Mg含量显著低于发病园(P<0.05);微量元素:健康园叶片中Fe、Mn、Cu含量显著高于发病园(P<0.05),Cl、Na和Zn含量显著低于发病园(P<0.05)。核桃不同发病程度土壤矿质元素含量之间差异比较:大量元素为健康土壤中TN、TP、TK、AN、AP、AK含量显著高于中度园和重度园(P<0.05);微量元素为健康土壤中Fe、Cu、Zn含量显著高于中度园和重度园(P<0.05)。健康土壤中Na、Cl含量显著低于中度园和重度园(P<0.05)。N和K在PC₁和PC₂中均为正值,并且呈正相关,对焦叶病发挥主要作用。施肥处理后,合理的根施N、K和叶喷N、K相结合效果最佳,发病率降到8%,并且土壤和叶片中的氮钾含量都显著上升。【结论】核桃焦叶病的发生与N、K含量低和Cl含量高有密切关系,合理补充N、K可有效防控核桃焦叶病。

关键词: 核桃, 焦叶病, 矿质元素, 施肥