苹果梨树冠光能利用的研究

STUDY ON LIGHT ENERGY UTILIZATION BY APPLE -PEAR TREE

对苹果梨树光合强度．光分布与花芽形成、座果情况的研究表明：苹果梨树光饱和点５８Ｋｌｘ、光补偿点２Ｋｌｘ，最大光合速率２７．４０ｍｇＣＯ２ｄｍ－２ｈ－１。影响光合作用的主要因子是光照强度、温度和ＣＯ２浓度。在自然生长状况下，冠内光分布的相对光强外区４１．２％、次外区２３．２８％、中区８．１％、内区２．８５％；光照与花芽形成、开花座果成正直线相关，相对光强在３．３％以下为无效区，３．３～１３％为过度区，花芽形成和座果所需的最低相对光强分别为２．０５％和３．７％。相对光强１３％时为产量形成的最低线。产量形成集中分布于树冠外围１ｍ左右的范围内，相对光强在２３％以上。

The net photosynthetic rare, Light distribution, flower_bud formation and fruit bearing of apple -pear tree were studied.The results were as follows:The light saturation point of apple pear tree was 58 Klx, the light saturation point was 2 Klx; The maximum photosynthetic rate was 27.40mg CO 2dm -1 h -1 ;The main factors that effected photosynthesis were light intensity, temperature and CO 2 concentrstion.In the natural growth state.The relative light intesity was 41.2% in the most exterior crown, 23.28% in exterior crown, 8.1% in middle crown,2.85% in central crown. The light intensity was positively related with the flower_bud formation, blssom and fruit bearing.There was an invalid area if the ralative light intensity was below 3.3%.There was an interim area if it was 3.3_13%. The minimum relative light intensity for flower_bud formation and fruit bearing were 2.05% and 3.7%. The minimim relative light intensity for yield formation was 13%. The yield formation was distriduted mainly ont of the crown about one metre. The relative light intensity was above 23%.