Leaf area index measurement by AccuPAR instrument in wheat

In order to measuring the leaf area index (LAI) of wheat canopy by AccuPAR at field condition, an experiment was conducted using seven wheat cultivars (Arya, Darya, Kuhdasht, Shiroudi, Tajan, Taro and Zagros) under irrigated and rainfed conditions during 2008-2009 at Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. This experiment was conducted as a Randomized Complete Block Design with four replications. LAI measuring was done by two methods, direct (destructive sampling) and non-destructive by AccuPAR from tillering stage to the canopy closure stage. The results showed that there was no significant difference between cultivars and the two conditions as aspect of equation coefficients, so one equation is usable for all cultivars under both conditions (LAI = 0.54 + 1.13 × LAI AccuPAR, R2=0.70). This equation can be used for estimation of actual LAI from calculated LAI by the AccuPAR.