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.