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1988～1989年,在浙江林学院果园调查了成年桃树叶幕结构、光能分布和光合强度。结果表明,5月中旬之前,叶幕已占全树最终叶片总面积的82.20％,生长高峰期叶片日平均生长量可达2.80m~2,桃叶面积系数在5～6之间。叶面积系数与新梢平均长相关最为突出。整个生长季节叶幕光能分布与叶面积系数呈极显著负相关。叶幕光强的日变化,随自然光强的变化而改变,以午间为最大,离午间越久的时刻则越小。叶幕纵剖面日平均透光率的总趋势是:叶幕上层和中心区大,下层和两侧小。田间条件下桃树光合作用的光饱和点为64.0klx,光补偿点为4.0klx,上层叶幕光合强度可达12.100mgCO_2dm~(-2)h~(-1),下层只有上层的51.24％,气温与叶幕光合强度有密切关系,炎热干燥季节明显下降。高温季节低光强叶幕区光合强度超过高光强区,因之在盛夏下层叶幕的同化作用不可忽视。
From 1988 to 1989, the leaf structure, light energy distribution and photosynthetic intensity of adult peach trees were investigated in the Orchard of Zhejiang Forestry College. The results showed that by the middle of May, leaf curtain had accounted for 82.20% of the total leaf area of the whole tree. The average daily growth of leaves reached 2.80m ~ 2 and the leaf area coefficient was between 5 ~ 6. Leaf area coefficient and the average shoot length the most prominent. There was a significant negative correlation between leaf light energy distribution and LAI during the whole growing season. Leaf light intensity diurnal changes, with the natural light intensity changes, noon to maximum, the longer the time from midday to the smaller. The general trend of daily average transmittance of leaf profile is: the upper and the middle of the leaf curtain are large, the lower and the two sides are small. Under field conditions, the light saturation point of peach tree photosynthesis was 64.0klx, the light compensation point was 4.0klx, the photosynthetic intensity of the upper leaves was 12.100mgCO_2dm -2 h -1, the lower layer only 51.24% of the upper layer, Temperatures and leaf photosynthetic intensity are closely related to the hot and dry season decreased significantly. The photosynthetic intensity of low light intensity leaf curtain area in high temperature season exceeded the high light intensity area, so the assimilation effect of lower leaf curtain in midsummer can not be neglected.