Mohsen Javaheri - Department of Agronomy, Qorveh Branch, Islamic Azad University, Qorveh, Iran

Sunflower is one of the most important edible oil that growth of annual crops, it is grown over a widely area and is considered a crop adapted to an every environmental conditions, in order to study growth analysis of sunflower under sowing date and cultivars in dry condition a farm experiment was conducted a split plot arranged in a complete randomized block design with three replications in the Dry Research Station. Main plots consist of four level sowing dates with ten-day intervals from (March ۳۰ - April ۳۰) and subplots consist of three cultivars: Record, Zarya and Azargol. In different sowing dates observed that sunflower plants had slow growth in the primary stage afterwards had a quick growth, so in second sowing date sunflower plants had a quick growth with received ۱۲۲۰ growing degree days. Among different cultivars, Record, cultivar had highest crop growth rates and relative growth rate. Record cultivar with ۱۲۵ days had highest growth duration and Zarya with ۱۲۲ days had lowest growth duration so sowing date and cultivar had a significant effect on grain yield, grain yield reduced with delayed in sowing date and Record had a highest grain yield. Results of evaluation total dry matter (TDM) showed that Record cultivar had highest total dry matter also, among different cultivars statistical significant different was observed thus delay in sowing date reduced oil yield and highest oil yield was obtained from Record cultivar.

Crop growth rate, Dry condition, Grain yield, Growth analysis, sunflower