EFFECTS OF AIR TEMPERATURE DURING SOYBEAN SEED FILLING ON SEED QUALITY

Reproductive development and growth stages of crops are especially important for seed production and affect seed quality. In order to evaluate the effect of planting date via canopy temperature during reproductive growth stages on soybean seed germination and vigor, an experiment was conducted at two locations, experimental farm of seed and plant certification and registration institute in Karaj and experimental farm of agricultural and natural resources center of Moghan, Ardabil, Iran, in 2013. Soybean varieties Williams and L17 were sown the rate of 40 plants/m^2 at May 5, June 5, and July 5. The experiment was conducted as a factorial based on randomized complete block design (RCBD) with three replications. Means comparison of three-way interaction made clear that highest percentage of normal seedling (98.3 %) was gained from L17 that was planted at 5th July in Karaj, furthermore the lowest normal seedling percentage (84.7) was obtained from Williams that was planted at 5th May in Moghan. Means comparison results noticed that the highest final abnormal seedling percentage (7.2 ) was seen in Williams cultivar in Karaj and the lowest rate of it (3.9 percent) was obtained from this cultivar in Moghan. Furthermore the lowest rate of seedling vigor index was obtained from Williams cultivar (89.9) that planted at 5th May in Karaj and L17 cultivar (99.2) that planted at 5th July in Moghan.