Response of Some Fall and Spring Type Rapeseed Cultivars to Normal and Late Planting Date

The present study aimed to the effect of late and normal sowing date on agronomic characteristics of some spring and fall rapeseed cultivars was evaluated during two years.

A field experiment in a split plot based on a randomized complete block design was carried out with four replications at the research station of Islam abad-gharb. Main factor was planting date in two levels including September 27 and October 17 and sub factor was rapeseed cultivars including Okapi, Talaye, hyola 401, Zafar, RGS003 and sarigol.

The results of variance analysis showed that the effect of late planting was significant only on days to flowering and plant height. Grain yield decreased by 34.4% and 29.85%, due to the delay in planting date in the first and second year of the experiment, respectively. This decrease was due to the effect of late planting date on yield components, so that decrease in the number of pods per plant as the most important component of grain yield in rapeseed in the first and second years of the experiment was 32.7 and 30.2%, respectively. The results showed that the cultivars had significant differences for number of days to flowering, flowering duration, number of days to physiological maturity, plant height, number of pods per plant, grain yield and seed oil percentage. The mean of the data showed that Okapi and Talayeh as fall type cultivars had the highest grain yield with 5096 and 4906 kg ha-1 respectively.

Okapi and Talaie are suitable cultivars for the study area. Also, any delay in planting causes yields reduced compared to normal conditions. However, considering other existing issues can be ignored reduction in performance.