轮台白杏果实不同生育期叶片光谱特性及对氮磷钾的敏感性

目的]通过分析果实不同生育期叶片光谱反射率对N、P、K的响应,探寻采用叶片光谱指数诊断N、P、K的敏感期,为轮台白杏简便快捷的非破坏性营养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光谱仪测定轮台白杏在不同N、P、K施肥水平下果实膨大期、着色期、成熟期、收后期叶片光谱反射率.结果]轮台白杏果实不同生育期叶片光谱反射率变异依赖于波长,变异最小的波段位于可见光范围,且光谱反射率呈现膨大期＞成熟期＞收后期＞着色期.在不同N、P、K施肥水平下,轮台白杏果实不同生育期叶片光谱指数(ND705)之间均存在显著差异(P＜0.05)或极显著差异(P＜0.01).结论]果实着色期是轮台白杏N素叶片光谱营养诊断的敏感期,果实膨大期是P、K素叶片光谱营养诊断的敏感期.

Leaf Spectral Characteristics and Its Sensitivity to N,P, K in Different Fruit Growth Periods of Armeniaca vulgaris 'Luntaibaixing'

【Objective】Sensitive stages of leaf spectral index used for N,P,K diagnosis were explored by analyzing the effect of N,P,K on leaf spectral reflectance in different fruit growth periods to provide the best temporal window for noninvasive,simple and rapid nutritional diagnosis of Armeniaca vulgaris ’Luntaibaixing’.【Method】Based on "3414" fertilizer effect field experiments,leaf spectral reflectance in the fruit swollen period,fruit coloured period,fruit mature period,fruit harvest period under diverse N,P,K fertilization levels were measured with Unispec-SC.【Result】The variation of leaf spectral reflectance of A.vulgaris ’Luntaibaixing’ in different fruit growth periods relied on the wavelength,the smallest variance which appeared in the visible light range and the leaf spectral reflectance was fruit swollen period>fruit mature period>fruit harvest period>fruit coloured period.The difference of leaf spectral index ND705 in different fruit growth periods under diverse N,P,K fertilization levels were significant or extremely remarkable.【Conclusion】The fruit coloured period was the most sensitive stage for spectral nutritional diagnosis of nitrogen and the expanding period was the most sensitive stage for spectral nutritional diagnosis of phosphorus and potassium of A.vulgaris ’Luntaibaixing’.