树冠直接覆膜对清见橘橙树冠内环境因子的影响

以清见橘橙(Citrus sinensis*Citrus unshiu Marc)为材料,研究了果实越冬期间直接覆盖薄膜的树冠内环境因子的变化.结果表明,覆膜可显著提高树冠内温度,2007-2008年试验期间的日平均温度在覆膜树冠上部为11.5℃,中部为10,5℃,下部为9.0℃,对照为8.3℃;2008-2009年试...

Effects of film covering on environmental factors inside the canopies of Kiyomi tangor trees

Kiyomi tangor(Citrus sinensis ×Citrus unshiu Marc) trees were covered by polyethylene film from Dec.2007 to Mar.2008,from Dec.2008 to Mar.2009 in Beibei of Chongqing in order to investigate the changes of environmental factors inside the film-covered tree canopies.Results showed that film-covering significantly increased the temperature inside the tree canopies.During the 2007-2008 experimental period,the average daily temperatures of the upper,middle and bottom part of tree canopies covered by polyethylene film were 11.5 ℃,10.5 ℃ and 9.0 ℃,respectively,while the uncovered trees(control) was 8.3 ℃.During the 2008-2009 experimental period,the average daily temperatures of the upper,middle and bottom part of tree canopies covered by polyethylene film were 11.0 ℃,10.2 ℃ and 9.6 ℃,respectively,and the control was 9.3 ℃.Inside the film-covered tree canopies,the daily temperatures on sunny days increased greater than those on rainy or overcast days.In most cases,the daily average relative humidity inside the film-covered tree canopies was markedly lower than those of the control before March,whereas an opposite trend was noted in March.Compared with the control,photosynthetic active radiation(PAR) at the upper and middle part of the tree canopies covered by film was reduced 23.7%-58.0% and 38.4%-74.1%,respectively,and the largest PAR decline happened in the morning.Fruit drop rate of film-covered trees declined significantly,and the accumulative fruit drop rate of the film-covered trees was only 1/4-2/5 of that of the control during the experimental periods.