根外追肥对银杏光合作用的影响

Effect of Foliage Spray on Photosynthesis in Ginkgo biloba L.

为解决银杏育苗中土壤养分供应不足导致光合作用差、幼苗生长较弱的问题,试验拟采取根外追肥方式供给银杏养分,提高其光合效率促进生长。以3年生银杏幼苗为试材,设置T1(CK)、T2(0.50%尿素和0.50%过磷酸钙)、T3(0.50%尿素和0.50%磷酸二氢钾)、T4(0.50%尿素、0.50%磷酸二氢钾、0.10%微量元素)4个处理,田间小区试验设计,3次重复。结果表明:银杏不同月份净光合效率不同,追肥种类不同对净光合速率的影响不同,整个试验期间T4处理净光合速率均显著高于对照;根外追肥可以提高银杏叶片的蒸腾速率,T3、T4与对照相比差异显著,T3、T4之间无显著差异;除7月份之外,其余月份T4处理气孔导度始终处于最高值,与对照相比差异显著,其次为T3处理,T2处理对提高银杏气孔导度效果不显著;胞间CO2浓度除7月份之外,T4处理均处于最低值,与对照相比差异显著;根外追肥可以影响银杏叶片水分利用效率。综合分析认为,T4处理对提高银杏叶片光合效率效果最佳。

In order to study the problems of poor photosynthesis and weak seedling growth of Ginkgo biloba L.which are caused by soil nutrient deficiency in seedling stage, a test was conducted to supply nutrient for Ginkgo biloba L. by foliage spray to improve the photosynthetic efficiency and promote plant growth. 3-year-old Ginkgo biloba L. seedlings were taken as the test materials, the author set 4 treatments as T1（CK）, T2（0.50%urea and 0.50% superphosphate）, T3（0.50% urea and 0.50% KH2PO4） and T4（0.50% urea, 0.50% KH2PO4 and 0.10% trace elements）, and a field experiment design that repeated 3 times. The results showed that thenet photosynthetic efficiency of Ginkgo biloba L. was different in different months, the influence of differenttypes of fertilizers on net photosynthetic rate was different, and the net photosynthetic rate of T4 treatmentthroughout the whole trial period was significantly higher than that of the control. Foliage spray could improvetranspiration rate of Ginkgo biloba L. leaf, T3 and T4 were significantly different from the control, and therewas no significant difference between T3 and T4. The stomatal conductance of T4 treatment was always at thehighest value except in July and it had significant difference compared with that of the control, the second wasthat of T3 treatment. The effect of T2 treatment on Ginkgo biloba L.＇s stomatal conductance was not significant.The intercellular CO2 concentration of T4 treatment was at the lowest value except in July and it wassignificantly different from that of the control; foliage spray could influence the water use efficiency of Ginkgo biloba L. In conclusion, T4 treatment had the best improvement effect on the photosynthetic efficiency of Ginkgo biloba L.