新温185号核桃果实不同生育时期叶片光谱特征及其对氮磷钾的敏感性

Leaf Spectral Characteristics and Its Sensitivity to N,P,K in Fruit Different Fruit Growth Periods of Juglans regia‘Xinwen185'

【目的】分析果实不同生育时期叶片光谱反射率对氮（N）、磷（P）、钾（K）的响应,探寻采用叶片光谱指数监测和诊断N、P、K的敏感期,为新温185号核桃树体简便快捷的非破坏性营养监测与诊断提供最佳时间窗。【方法】基于＂3414＂肥料效应田间试验,利用Unispec-SC光谱仪测定新温185号核桃在不同N、P、K施肥水平下果实速生生长期、硬核期、脂化期、成熟期叶片光谱反射率。【结果】新温185号核桃果实不同生育时期叶片光谱反射率依赖于波长,在360-1 100 nm波长范围内受大气吸收干扰和仪器噪声影响很小;果实不同生育时期叶片光谱反射率对N、P、K肥的响应有所差异;在不同N、P、K施肥水平下,新温185号核桃果实速生生长期叶片光谱指数（ND705）与硬核期、脂化期、成熟期之间均存在极显著差异（P〈0.01）。【结论】果实速生生长期是新温185号核桃树体N、P、K营养元素光谱监测与诊断的敏感时期。

[Objective]The sensitive stage of leaf spectral index used for nitrogen （N）, phosphorus（ P）, potassium （K）monitoring and diagnosis was explored by analyzing effect of N ,P,K on leaf spectral reflectance in different fruit growth periods in order to provide the best temporal window for noninvasive, simple and rapid nutritional monitoring and diagnosis of Juglans regia＇Xinwen185＇. [ Method] Based on ＂3414＂ fertilizer effect field experiments, leaf spectral reflectance in the fruit rapid growth period, hardcore period, fat change peri- od, mature period under diverse N, P, K fertilization levels were measured with Unispee - SC. [ Result ] The leaf spectral reflectance of J. regia＇Xinwen185＇in fruit different growth periods relied on the wavelength, and it was slightly influenced by atmospheric absorption interference and noise of instrument in 360 - 1 100 nm wavelength range; the leaf spectral reflectance of fruit different growth periods responded differently to N, P, K fertilizer; the differences of leaf spectral index NDTo5 in fruit rapid growth period compared to hardcore period, fat change period and mature period were highly significant（P 〈 0.01 ） under different N, P, K fertilizer levels. [ Conclusion ] The fruit rapid growth period was the most sensitive stage for spectral monitoring and diagnosis of nitrogen, phosphorus and potassium nutritional elements of J. regia ＇ Xinwen185＇