锥栗不同树形对冠层光照及产量品质的影响

Effect of different tree shape on canopy light and yield and quality of Castanea henryi

以‘华栗3号’锥栗为试材,采用田间调查法系统研究了锥栗3种主要树形的枝类组成、冠层内相对光照强度、叶片质量、果实产量和品质等指标.结果表明,开心形树冠整体光照条件良好,各层光照分布均匀一致,无效光区比例最低(27.78%),枝量主要集中在树冠中、上层,分别占全树的45.52%和36.04%;自然圆头形树冠光照相对较差,各层光照分布不均匀,无效光区比例最高(36.11%),枝量主要集中在中、下层,分别占全树的34.96%和40.11%;3种树形的长、中、短枝的比例变化不大,均以短枝为主,短枝比例分别占73.06%(小冠疏层形)、70.81%(自然圆头形)和66.47%(开心形).开心形树冠上层的叶片比叶重最大值为15.77 mg·cm-2,显著高于自然圆头形和小冠疏层形;而自然圆头形树冠中下层的SPAD值显著高于开心形和小冠疏层形.开心形结果部位主要集中在光照条件较好的中、上部位,占单株产量的69.48%,而自然圆头形结果部位集中于相对光照强度急剧下降的下部,二者的单株产量差异不显著,但均显著高于小冠疏层形.开心形树冠下层果实的单粒质量、可溶性糖含量、还原性糖含量和淀粉含量分别为6.45 g、6.92%、0.62%和60.56%,均显著高于小冠疏层形和自然圆头形.综上可知,开心形树形结构合理,光照条件好,品质高,增产潜力大.

In order to explore the suitable tree and tree structure of Castanea henryi variety‘Huali 3＇. TES-1335 digital illuminance meter and field survey method were used to study the following traits of three kinds of tree shapes： the branch composition,the relative light intensity in the canopy,the leaf quality,fruit yield and quality indicators. The results showed that： in open heart shape of tree,overall illumination condition was good,the distribution of light in each layer was uniform,and the ratio of the ineffective light area was the lowest（ 27.78%）. The branches were mainly concentrated in the middle and upper layers,which were 45. 52% and36.04%,respectively. In natural round shape of tree,the crown was relatively poor in light,the distribution of illumination was uneven,and the proportion of ineffective light areas was the highest（ 36.11%）. The branches were mainly concentrated in the middle and lower layers,accounting for 34.96% and 40.11% of the total tree respectively. The proportion of long,middle and short branches of the 3 tree species changed little. They were mainly short branches,and the proportion of short branches accounted for73.06%（ small crown sparse shape）,70.81%（ natural round head shape） and 66.47%（ open heart shape）. The maximum value of specific leaf weight on the top of open heart shape of tree was 15.77 mg·cm-2,which was significantly higher than that of natural round head shape and small crown sparse shape of tree. The SPAD value of the middle and lower layers of the crown of natural round head shape was significantly higher than that of open heart shape and small crown sparse shape. The fruiting position of open heart shape of tree was mainly concentrated in the upper and middle parts with better light conditions,accounting for 69.48% of the yield per plant. The fruiting position of natural round head shape of tree was concentrated on the lower part with relatively weak light.There was no significant difference in yield per plant between the two species,but all of them were significantly higher than those of small crown sparse shape of tree. The single slice weight,soluble sugar content,reductive sugar content and starch content of the fruit of the lower canopy of open heart shape of tree were 6.45 g,6.92%,0.62% and 60.56%,respectively,which were all significantly higher than that of small crown sparse shape and natural round head shape of tree. In conclusion,the open heart shape of tree is reasonable,its light condition is good,the fruit quality is high,and the yield potential is great.