胡椒园间作槟榔对胡椒光合效应和产量的影响

为揭示槟榔胡椒间作体系中胡椒间作产量优势的光合机理,2009~2012年在海南胡椒与槟榔间作优势区,研究4种间作和单作条件下,胡椒不同生育期完全展开叶的光合有效辐射、净光合速率、气孔导度、蒸腾速率和胞间二氧化碳浓度等光合参数以及叶面积和叶绿素的含量。结果表明:胡椒与槟榔间作明显提高胡椒产量,偏土地当量比(PLER-M)高于其所占面积比例的134%~189%,表现出明显的间作产量优势。分析胡椒光合参数与产量相关关系,发现胡椒灌浆期光合参数与产量显著或极显著正相关,其中气孔导度对产量的正效应最大,以气孔导度为解释变量与因变量产量做回归分析,发现灌浆期对产量的贡献率达52%。胡椒与低密度槟榔间作提高或显著提高了胡椒灌浆期叶片光合作用,增强二氧化碳的固定,这可能是胡椒产量间作优势的主要来源。

Effects of Intercropping on Black Pepper Photosynthesis and Yield in the Black Pepper/Arecanut Intercropping System

In order to reveal the photosynthetic mechanism of black pepper yield advantage in intercropping system, experiments with 5 treatments in pepper and arecanut intercropping advantage region of Hainan Province from 2009 to 2012 was conducted. Photosynthesis parameters such as photosynthetic active radiation, net photosynthetic rate, stomatal conductance and intercellular carbon dioxide concentration of pepper fully expanded leaves at different stages were determined. Leaf area and chlorophyll content were also measured. The results showed that the yield of black pepper increased in black pepper/arecanut intercropping system. Partial land equivalent ratio(PLER-M)was 134%-189% higher than its total area. It showed significantly yield advantages. There was significant or very significant correlations between photosynthesis parameters and yield of black pepper. The stomatal conductance had the highest positive effect on the yield. Using stomatal conductance as the explanatory variable and yield as the dependent variable, 52% yield variation could be explained. Pepper intercropping with low density arecanut increased the pepper leaf photosynthesis and improved carbon dioxide fixation in the filling stage, which could be the main reason of intercropping yield advantage of pepper.