不同时期施钾肥对油桃幼树光合特性的影响

Effects of Potassium Fertilizer Applied at Different Stages on the Photosynthetic Characteristics of Young Trees in Greenhouse

以沪油018幼树为试材,研究了设施条件下钾肥施用时期对幼树光合特性的影响。结果表明:与对照相比,不同时期施钾肥后,叶片净光合速率(Pn)均有不同程度地提高,而果实膨大期施钾肥效果最明显。进一步研究发现,施钾可降低叶片气孔导度(Gs)、气孔限制值(Ls)和蒸腾速率(Tr);同时,提高了叶片胞间CO2浓度(Ci)和叶表温度(Tleaf)。

To explore the effects of potassium fertilizer applied at different time on the photosynthetic characteristics, young nectarine trees in greenhouse were trained to central leaders and planted at in-row spacing of 1m with 2m between rows. The results showed that; compared with control, fertilizer-applying at different growth stages improved Leaf net photosynthesis (Pn) to some degrees, and particularly applying potassium 150 gram per plant at fruit-fast-enlarging stage elevated Pn most prominently. It was further revealed that applying potassium chloride significantly increased leaf Intercellular CO2 concentration (Ci) and Temperature of leaf thermocouple (Tleaf), while obviously reduced leaf Conductance to H2O (Gs) and Limited value of stomatal (Ls) compared with control. Moreover, leaf transpiration in treatment was lower than that in control.