Effect of harvesting time on yield and yield compnents of oilseed rape cultivars in Sistan region

In order to study the effect of harvesting time on yield and yield components of oilseed rape, an split–plot experiment on the basis of randomized complete block design with three replications was conducted in Zahak Agircultural Research Station of Zabol during two cropping seasons (2002-2003 and 2003-2004). Two cultivars Sarigol (pf/7047) and (Hyola 308) were main plots and seven harvest times T1: harvest in 10% seed color change in siliques of main stem, T2: harvest three days after T1 stage, T3: harvest six days after T1 stage, T4: harvest nine days after T1 stage, T5: harvest twelve days after T1 stage, T6: harvest fifteen days after T1 and T7: harvest eighteen days after T1 stage were sub plots of the experiment. The Results showed significant differences on siliqua number in plant, 1000 seed weight, seed yield and oil yield from aspect of harvest time. Delay in harvest time caused decrease in seed yield, siliqua number in plant and 1000 seed weight. T3 had 33% and 32% higher yield than T6 and T7, respectively. Cultivars had significant differences for seed number in siliqua, seed yield, oil percent and oil yield. Hyola 308 with 3553 kgha-1 had 21% more yield than Sarigol. Oil percentage did not show significant difference in different harvest times. Oil yield changes in different harvest times followed the same manner as did seed yield. Other traits did not also show differences. Considering the results, harvesting 3-6 days after 10 percent seed color change in main stem siliques(30-40 % seed color change, approximately) and use of early maturity hybrids or cultivars are recommended for Sistan area and similar regions