摘要
【目的】研究基于盛花期冠层高光谱数据的苹果花量估测技术,为植株花果管理和生产力预测技术的建立奠定基础。【方法】以5年生M9无性系砧木‘米奇嘎啦’苹果(Malus pumila‘Mitch Gala’)、树形为高纺锤形的植株为试材,在盛花期采集植株冠层可见-近红外高光谱图像,人工统计供试植株花量,比对分析基于原始光谱反射率(original reflectance spectra,OS)与Savitzky-Golay平滑法(savitzky-golay smoothing,SG)、正态变量标准化(standardization of normal variables,SNV)、标准化(Normalize)、一阶求导(first derivation,lst Der)、二阶求导(second derivation,2nd Der)共5种预处理的高光谱数据的偏最小二乘法(partial least squares method,PLS)模型,以及基于载荷系数法(x-loading weight,x-LW)提取的特征波长的PLS模型、人工神经网络(the back-propagation neural network,BPNN)、最小二乘支持向量机(the least squares support vector machines,LS-SVM)等模型对单株单位面积花量实时估测精度的影响。【结果】苹果树单株花量与单株单位面积花量具有较高的相关系数,表明采用冠层单位面积花量替代单株总花量进行树体花量估测可行。单株单位面积花量与植株冠层光谱反射率在紫外-可见光波长(308—700 nm)呈极显著正相关,在近红外波长(750—1 000 nm)相关性不显著。基于全波长,以Normalize预处理光谱建立的PLS模型对单株单位面积花量的预测效果最好,校正集决定系数(R_c^2)和预测集决定系数(R_p^2)分别为0.794和0.804,校正集均方根误差(RMSEC)和预测集均方根误差(RMSEP)分别为0.084、0.062,预测相对误差(RE%)为3.940。基于特征波长的BPNN模型稳定性差,而LS-SVM模型的建模效果较好,R_c^2和R_p^2分别为0.826和0.804,RMSEC和RMSEP分别为0.077、0.064,RE%为12.160。【结论】基于Normalize预处理的PLS模型对高纺锤形苹果树冠层单位面积花量的预测效果最优,同时,本研究利用高光谱成
[Objective] To study a technology for estimating the number of apple flowers which is based on the hyperspectral image information of a canopy at full-bloom stage, in order to lay a foundation for the establishment of the technologies used for the management and the productivity prediction of the flowers and fruits of a plant. [ Method] The 5-year-old Malus pumila ＇Mitch Gala＇ trees with M9 clonal rootstocks in the shape of high spindles were studied. The visible and near infrared hyperspectral images of the canopy at full-bloom stage were collected, and the number of the flowers of the trees was selected and then counted manually Finally, comparatively analyze the effects of the Partial Least Squares （PLS） models based on the original reflectance spectra （OS） and the spectra pretreated by five kinds of methods including savitzky-golay smoothing（SG）, standardization of normal variables （SNV）, Normalize, first derivation（1^st Der）, second derivation（2^nd Der）, the PLS, the back-propagation neural network （BPNN） and the least squares support vector machines （LS-SVM） based on characteristic wavelengths obtained by x-loading weight （x-LW） on the accuracy of the real-time estimation of the amount of flowers per unit area per tree. [ Result ] Both the number of flowers per tree and the number of flowers per unit area per tree have high correlation coefficients, which means using the number of flowers per unit area of the canopy as a substitute for the total number of flowers per tree to predict the number of flowers of all the trees is feasible. The number of flowers per unit area per tree had a very significant positive correlation with the reflectivity of the trees＇ canopy in the ultraviolet and visible wavelength （308-700 nm）, but the correlation between the two was not significant in the near-infrared wavelength （750-1 000 nm）. Based on full wavelength, the PLS model based on spectra pretreated by Normalize predicts the number of flowers per unit area per tree most
出处
《中国农业科学》
CAS
CSCD
北大核心
2016年第18期3608-3617,共10页
Scientia Agricultura Sinica
基金
国家科技支撑计划(2014BAD16B02-2
2008BAD92B08-7-4)
国家国际科技合作专项(2013DFA11470)
重庆市科技支撑示范工程(cstc2014fazktpt80015)
