纽荷尔脐橙叶片喷施氮磷钾肥的光合响应

Photosynthetic Response of Newhall Navel Orange to Foliage Spraying NPK

为了研究叶面施肥对柑橘光合特性的影响,对纽荷尔脐橙进行叶面喷施NPK、NP、NK、PK、N、P、K和清水(CK)试验。结果表明:N、P、K元素无论是单独喷施或混合喷施,对提高脐橙叶绿素含量都有很好的效果,以NPK混合喷施的效果最好,N元素对柑橘叶片的叶绿素合成有显著的促进作用;各处理的净光合速率都明显高于对照,以混合喷施NPK的提高幅度最大,持久性较强,其他处理比对照增大的顺序为NK>PK>N>P>K;各处理对纽荷尔脐橙的蒸腾速率都有增强作用,在喷肥3 d后表现出降低的趋势,9 d时各处理的Tr仍然高于对照,12 d时只有NPK和P的处理仍然分别高于对照;不同的叶面肥可显著增加纽荷尔脐橙叶片的气孔导度,以NPK的影响最大,各处理的增强作用,在第3天时最大,随着时间的延长其作用逐渐减弱。喷施P和PK的叶片的胞间CO2浓度从第3天开始出现了增大的趋势,其他处理则呈降低趋势,持续降低时间最长的是混合喷施NPK处理。

The effects of foliar fertilization on photosynthesis characteristics of Newhall navel orange were studied,which contain foliar spraying the mixture of NPK,NP,NK,PK,N,P and K,and spraying water （CK） as control.The results showed that the chlorophyll content was increased after spraying N,P,K separately or mixed;y.And the mixed spraying d NPK had the best effect.N had significant promotion effect on chlorophyll synthesis in citrus leaves.The net photosynthetic rate of various treatments were higher than CK,and mixed spraying NPK had the best effect and durability.Other treatments followed the sequence d NK ＞ PK ＞ N ＞ P ＞ K;the tnmspimtion rate was enhanced under every treatment and decreeased three days later,and it was still higher than CK on the ninth day,12 days later only NPK and P tneatments had higher Tr than CK; Stomatal conductance was significantly enhanced with the highest effect of NPK weatment.The potentiation reached the highest on the third day and gradually decweased with time prolonging.Spraying P and PK increased potentiation CO2 concentration on the third day,other treatments showed declining trends,NPK meatment lasted the longest.