ANBAR JOURNAL OF AGRICULTURAL SCIENCES

Abstract

GENETIC PARAMETERS OF RAPESEED AS AFFECTED BY PLANTING DATE

N. O. Sarkees* , A. M. Al-Jumaily** , A. A. A. Ali* and R. H. Baker*
* Crop Sci. Dep. - College of Agriculture / Univ. of Baghdad
** Crop Sci. Dep. - College of Agriculture / Univ. of Al-Anbar

Abstract
A field trial was carried out at the experimental farm of the agricultural college, Abu-Ghraib during the growing season of 2003/2004 and 2004/2005 to investigate the effect of sowing dates on yield and yield components of eight rapeseed varieties. A split plot arrangement in randomized complete block design with three replicates was used. Planting dates were assigned at the main plots, where as the varieties were assigned in the sub plots.
The results shoed that phenotypic and genotypic variances and coefficients of variability were varied for all characters studied with difference of planting dates. The values of phenotypic variances and coefficients of variability were larger than the genotypic for all characters in both seasons. Broad sense heritability percentage was higher in the November 27th planting for 1000 seed weight for the first season. While plant height and number of seeds per pot showed higher value in September 28th planting, also number of pods per plant had higher value in the October 18th and November 27th planting of the second season .Higher values of co heritability coefficient was obtained between harvest index and number of branches per plant in the October 18th planting (3.13) of the first season, while higher co heritability coefficient between seed yield and number of pods per plant (10.88) was found in the September 28th planting in the second season. The result showed that most of the values of genotypic correlations were larger than the phenotypic for both seasons. In the first season positive highly significant phenotypic and genotypic correlations were found between seed yield and 1000 seed weight in the October 18th planting (0.785,0.816), November 7th planting (0.799,0.806), and November 27th planting (0.789,0.800) and with harvest index (0.647,0.806) in the October 18th planting. While in the second season positive highly significant phenotypic and genotypic correlations were found between seed yield and plant height in the October 18th planting (0.643 and 0.763), November 7th planting (0.550 and 0.635) and November 27th planting (0.820 and 0.876) and with number of branches per plant (0.599 and 0.835) in the November 27th planting, and with number of pods per plant in the October 18th planting (0.799 and 0.882) and November 27th planting (0.569 and 0.595), and number of seeds per pod (0.667 and 0.708) in the September 28th planting, and with the 1000 seed weight in the November 7th planting (0.694 and 0.789) and November 27th planting (0.590 and 0.638). A positive highly significant genotypic correlation was found between seed yield and harvest index (0.528) and positive significant phenotypic correlation (0.444) in the September 28th planting .Therefore , these traits could be used as criteria to improve seed yield of rapeseed as affected by different planting dates.