Abstract:

Objective: This study aims to evaluate the impact of different cultivation management factors on the incidence of jujube black spot (Alternaria alternata) and jujube gall midge (Dasineura jujubifolia) in the main Ziziphus jujuba (red jujube) production areas of Xinjiang, and quantify the relative importance of key factors, so as to provide a scientific basis for green and precise prevention and control of jujube tree pests and diseases. Method: This study was conducted in three major red jujube production areas of Xinjiang (Aksu, Hotan, and Kashgar). Thirty-nine orchards were selected, covering jujube varieties such as Huizao, Junzao, and Dongzao with the age of 7 to 20 years-old. The orchards were subjected to different cultivation management factors such as plant spacing, soil types, intercropping, irrigation, pruning, and fertilization practices. A five-point sampling method was used to investigate the incidence of jujube black spot and jujube gall midge. Data were analyzed using Excel 2016 and SPSS 22.0, and structural equation modeling (SEM) was performed in R language with the Lavaan package to assess the direct and indirect effects of cultivation management factors on jujube pests and diseases. The goodness of model fit was evaluated using the indicators of χ²/df, root mean square error of approximation (RMSEA), standardized root mean square residual (SRMR), goodness-of-fit index (GFI), and comparative fit index (CFI). Result: 1) The incidence of jujube black spot was influenced by both intrinsic factors (variety, tree age, soil type) and cultivation practices (pruning, fertilization, irrigation), with variety being the most important factor (standardized path coefficient = 0.68). Tree age not only directly increased disease incidence, but also indirectly affected it through pruning methods and plant spacing. Precise pruning markedly reduced disease incidence from 7.80% to 2.14%, while optimized fertilization and regular irrigation further decreased incidence by 2.99% and 2.97%, respectively. 2) The leaf-curling rate of jujube gall midge was mainly influenced by cultivar and pruning method, while irrigation regime and tree age had no significant effects. Fertilization practice and intercropping type did not directly affect the leaf-curling rate, but exerted indirect effects through pruning. Planting density (spacing) showed a direct effect on the leaf-curling rate, with the lowest leaf-curling rate (2.77%) observed under the standard spacing. 3) A “Five-Standardized” cultivation strategy for pest and disease resistance in jujube orchards was proposed, including: optimized intercropping (no intercropping or green manure rape), optimized planting density (avoiding high density, 1 m×3 m, 1 m×4 m), optimized irrigation (once every 25 days, 5?8 times per year), optimized pruning (retaining 35?40 fruiting shoots, with once pruning in December, and monthly pruning in summer), and optimized fertilization (3?5 applications per year). Conclusion: The integrated “Five-Standardized” control model for pest and disease resistance in jujube orchards shifts the focus of prevention and control to cultivation management measures such as pruning, fertilization, irrigation, plant spacing and row spacing, and intercropping types, which can be artificially regulated. This method can effectively reduce the occurrence risk of jujube black spot disease and jujube gall midge, decrease the application of chemical pesticides, and facilitate the green and high-quality development of the red jujube industry in southern Xinjiang.

Key words: Ziziphus jujuba tree, cultivation, jujube black spot disease, jujube gall midge, structural equation model