采用LAI-2000植物冠层分析仪观察桑树生长变化及测算桑叶产量

Application of Plant Canopy Analyzer LAI-2000 on Investigating Growth Situation of Mulberry and Estimating Yield of Mulberry Leaves

利用LAI-2000植物冠层分析仪对田间生长桑树进行生长过程观察及桑叶产量测定，结果显示：桑树收获条桑后的2个月内，当叶面积指数（LAI）〈1．0时桑树的生长非常缓慢，当LAI〉1．0之后，桑树的生长速度大大加快，直至LAI达到最大值6．0，LAI值越大桑园透光率（DIFN）越小，但两者不呈简单的线性关系；随着桑树的生长，叶片的倾斜角度基本保持36°～45°，绝大多数集中在42°左右。于桑园LAI不同的3个时期测算的桑叶产量与实际产量相比，误差分别为-8．6％、-8．5％和＋1．5％，认为采用该分析仪测算桑叶产量具有方便、快速且无损桑树生长的特点。

We used Plant Canopy Analyzer LAI-2000 to investigate the growth process of mulberry and estimate the yield of mulberry leaves. The results showed that when the leaf area index （LAI） was below 1.0, the growth speed of mulberry was very slow during 2 months after brunch-harvesting. When the LAI surpassed 1.0, the growth speed of mulberry increased quickly. However, when the LAI reached to 6.0, the speed decreased instead. It also showed that the higher the diffuse non-interception （DIFN） of mulberry field was, the lower the LAI, but with not simple linear relationship. The mean tilt angle （MTA） of mulberry kept between 36°- 45°, and mostly around 42° during growth stage. We also found that the error between estimation and actual yield at 3 different periods were -8.6%, -8.5% and ＋1.5%, respectively. The above results indicated that the application of Plant Canopy Analyzer on estimating yield of mulberry leaves had characteristics of convenience, high speed and free of injury.