Estimating rice leaf area index at North Iran

Leaf Area Index (LAI)، is a key component in estimating crop yield and environmental stresses. Given the importance of accurate determination of these parameters، the present study was aimed to estimate the LAI of rice plant. For this purpose، 20 paddy fields were selected. The data required to perform the operations in the study area were corrected by land impressions (direct method) and measured by AccuPAR (indirect method). Field work to gathering LAI were taken at intervals of 16 days from seedling stage to the flowering stage of rice plants. The results showed that the lowest and highest levels of LAI belongs to seedlings and flowering stages، respectively. The leaf area obtained by both methods، were almost the same for each farm during different stages of plant growth. Consistent with the obtained values by both methods، indicate that the index can be calculated from a derived empirical relationship. Based on this empirical formula for every stage of plant growth، weka3. 7 software was adopted to calculate the mentioned relationship.