Evaluation of soybean cultivars and improved lines to photoperiod in field conditions

Photoperiod effects were evaluated on quantitative and qualitative of Soybean lines and cultivars in 2001-2002. Fifteen soybean genotypes were evaluated at Four sowing dates, 5 May, 20 May, 4 June and 18 June in Karaj, sixteen soybean genotypes were evaluated at Four sowing dates, 26 May, 10 June and 25 June and 10 July in Dezfoul, Fifteen soybean genotypes were evaluated at three sowing dates, 4 May, 19 May and 3 June in Moghan. Soybean genotypes were cultivated as base of randomize complete block design in each sowing dates. Phenologic, morphologic, yield and yield components, harvest index and seed oil and protein content were analyzed and means were compared by Duncan's test at 5% probability level. Date of flowering and duration of reproductive stage with growth degree days (gdd), day length (dl) and photo thermal units were fitted by multiple regression method. Karaj: Results showed that all phenologic characteristics were affected by date of cultivation soybean genotypes and bilateral effects. Days to flowering, beginning bloom, beginning pod, beginning seed, end of flowering, full maturity, and reproductive stage duration were significant different in sowing date, soybean genotypes and bilateral effect of them. All morphological characteristics were affected by date of cultivation. There were significant differences in yield and yield components of date of cultivation, soybean genotypes and bilateral effect of them. Number of pod in main stem, number of pod in branches, number of pod in plant, number of seed in main stem, number of seed in branches, number of seed in plant, 100 seed weight, yield and harvesting index were affected by sowing date and genotypes. Comparison of means with Duncan's test showed that the highest and lowest yield were produced at the first cultivation with average of 2600 Kg/hectare and the 4th cultivation date with 1200 Kg /hectare,respectedly.M4 with 2300 Kg/hectare and Elf with 1400 Kg/hectare produced the highest and lowest yield in the experiment. Williams in first cultivation date with 3090 Kg/hectare and Elf in 4th cultivation with 882 Kg /hectare had higher and lower production, respectively. Seed oil and protein percentage holds negative correlation at 0.01 level. In all genotypes, gdd, dl and photo thermal had effective consideration on time of flowering, but Union and Clark were except. Dezfoul: the result showed that there were significant differences in sowing date, soybean genotype and their interaction in all characteristics. Delaying in sowing date cause to postpone time of development stages. Node number, height and branch number were affected by cultivar and sowing time. Yield and yield components were affected by sowing date, significantly. Safiabad, Daglas× SF-1 and T1× Semmes produced the highest yield with 3400 kg/ha. Days to flowering of Safiabad had the highest sensitivity, but Alcatra 1.4, DPX, Essex and T1×Semmes were very sensitive to photoperiod. Moghan: The results showed that sowing date had significant effect on phenological characteristics and yield. Iroquois produced the highest yield with 2700kg/ha