关键词: 小麦, 叶面积指数, 生长性状, 产量, 产量结构, 植被指数

Abstract:

In order to provide the basis for using MODIS vegetation index to monitor wheat growth and estimate yield, the variance analysis of growth characteristic, yield and yield components of two varieties of spring wheat was carried out by using the observation data of two varieties of spring wheat from 1994 to 2012 in Yongning Agrometeorological Experiment Station of Ningxia, then the samples with no significant difference between the two varieties of spring wheat were selected to establish the relationship between LAI at different growth stages and plant height, density, yield, panicle number per unit area, grain number per spike and 1 000 grain weight.   The results show that LAI could reflect the changes of the plant height, density and the number of panicles per unit area at different development stages. The plant height could be estimated by using LAI from the heading to milking stage, the plant density could be monitored by LAI from the trefoil to milky stage, and the monitoring effect was best from the jointing to milking stage. The number of effective panicles per unit area could be estimated by LAI from the heading to milking stage, which was best at heading stage. LAI from the heading to milking stage could reflect the change of wheat yield better. The vegetation index, which can be constructed by wheat canopy hyperspectral measurement value or by MODIS Terra/Aqua data, could be used to estimate LAI, and then the yield could be estimated by the relationship between LAI and yield. The wheat growth could be monitored by the relationship between LAI and plant height and  density of wheat if LAI was estimated by remote sensing vegetation index at different growth stages. LAI retrieved from MODIS vegetation index was relatively stable during the heading to early filling stage and it could be used to estimate the wheat density, yield and yield components.

Key words: wheat, LAI, growth characters, yield, yield components, vegetation index