调亏灌溉对滴灌核桃树光合特性及产量的影响

Effect of Regulated Deficit Irrigation on Photosynthetic Characteristics and Yield of Drip Irrigation Walnut Trees

研究调亏灌溉对滴灌核桃树叶片光合特性及产量的影响,找到核桃树最适宜调亏的生育期,对发展核桃产业具有科学指导意义。本试验分别在萌芽期(Ⅰ)、开花坐果期(Ⅱ)和萌芽期开花坐果期(Ⅰ+Ⅱ)进行调亏,分析不同调亏程度及复水后核桃树叶片的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO-2浓度(Ci)指标及产量变化情况。调亏灌溉下,与正常灌水相比,开花坐果期调亏的叶片Tr和Gs显著降低(P<0.05)。与充分灌水相比,萌芽期亏水于开花坐果期复水的叶片Tr、Gs和Ci显著降低(P<0.05);果实膨大期复水的叶片光合特性都增大,随着调亏度的增大而减小。调亏灌溉对果实产量均起到正作用,开花坐果期轻度调亏和萌芽期开花坐果期轻度调亏的单株产量较高。综合试验分析表明,确定开花坐果期轻度调亏为核桃树最适宜的调亏处理。

Studying the effects of regulated deficit irrigation on the photosynthetic characteristics and yield of walnut leaves under drip irrigation and finding the optimal growth period of regulated deficit in walnut trees are of scientific guiding significance for the development of walnut industry.The regulated deficit irrigation experiment was respectively carried out in the germination stage(Ⅰ),flowering and fruit bearing periods(Ⅱ),germination stage and flowering and fruit bearing periods(Ⅰ+Ⅱ).And the net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),intercellular CO2 concentration(Ci)indicators and yield changes of walnut leaves after different adjustment and rehydration were analyzed.The results showed that:under regulated deficit irrigation,compared with normal irrigation,the Tr and Gs of the regulated deficit at flowering and fruit bearing periods were significantly reduced(P<0.05);compared with normal irrigation,the water deficit during the germination period and the rehydration during the flowering and fruiting period significantly reduced the Tr,Gs and Ci of the leaves(P<0.05);the photosynthetic characteristics of the leaves in the fruit swelling stage were all increased,and decreased with the increase of regulation deficit;regulated deficit irrigation had a positive effect on fruit yield,and the yield per plant was higher for the treatment of slightly regulated in the flowering and fruiting bearing periods and the treatment of slightly regulated in the germination stage and flowering and fruiting bearing periods.The comprehensive experimental analysis showed that the mild regulation in flowering and fruiting period was the most suitable deficit treatment for walnut trees.