两种密度模式下核桃生产性能差异研究

Study on the Difference of Production Performance of the Two Density Types of Walnut

【目的】研究新疆核桃生产中两种主要密度模式下主栽品种‘温185’的群体结构、光合特性,为生产实践中核桃种植密度调整、稳产增产、提高果品质量提供理论依据。【方法】采用LAI-2000冠层仪、SPAD-502叶绿素仪、Li-6400便携式光合测定系统、FMS-2叶绿素荧光仪,对两种主要密度模式下主栽品种‘温185’的群体结构、生理指标、光合性能分阶段性进行测定,对比分析两种密度模式下各生育阶段冠层结构差异、光合性能及产量品质差异。【结果】两种密度模式LAI值在树体进入花芽分化期后存在显著差异,5 m×3m模式介于2.7~5.6,5 m×6 m模式介于1.1~4.2;5 m×3 m密度模式LAI值超过合理限值,枝叶形成相互遮荫,冠层内部、中下部叶片受光不足,CO2饱和点、光补偿点、光饱和点均低于5 m×6 m密度模式,生育后期叶片早衰,群体光合能力随之下降,产量、单果重等5 m×6 m密度模式、出仁率在后期不能持续保持,树势早衰、残次果率较高。【结论】5 m×6 m密度模式有较为良好的群体结构和健康生理指标,群体内部光环境良好,在生产中能够维持较长时期持续群体光合的能力,对提高产量和提高质品质更为有利。

【Objective】In order to provide theoretical basis for planting density adjustment,stable yield increase and fruit quality improvement for guiding production practice,the population structure,physiological index and photosynthetic characteristic of the main- planting walnut variety＇Wen 185＇under two types of planting densities in Xinjiang.【Method】Using the varieties of canopy structure,photosynthetic rate,the effects on canopy structure and photosynthetic rate were determined by using LAI- 2000 plant canopy analyzer,SPAD-502 chlorophyll meter,Li- 6400 portable optical measurement system,and FMS- 2 chlorophyll fluorescence detector,respectively; fruit yield and quality were analyzed in two types of planting densities at all growth stages.【Result】After entering flower bud differentiation period,the clear difference of walnut＇s LAI value existed in two types of planting densities. LAI value of 5 m × 3 m mode was between 2. 7 and 5. 6,and the LAI value in 5 m × 6 m mode is between 1. 1 and 4. 2. LAI value in 5 m × 3 m mode exceed in the reasonable range,and the walnut＇s branches and leaves shaded each other,which led to lack of light inside the canopy and lower leaves CO2 saturation point and light compensation point in this mode were lower than 5 m × 6 m mode. In addition,leaf senescence,photosynthetic capacity decreased,yield and single fruit weight were also lower than 5 m × 6 m mode; Kernel rate in the later could not continue to maintain,as well as tree vigor premature senility,and higher defective fruit rate.【Conclusion】5 m × 6 m density model for the walnut plants has a relatively good population structures and healthy physiological index and maintain the ability of continuous photosynthesis in the practice,which are favorable for enhancing yield and qualities.