RESPONSE OF SIX BREAD WHEAT GENOTYPES TO DIFFERENT SOWING DATES | ||
| Egyptian Journal of Agricultural Research | ||
| Article 11, Volume 86, Issue 3, September 2008, Pages 957-971 PDF (3.52 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejar.2008.209029 | ||
| Author | ||
| ABDEL-SALAM M. M. MENSHAWY | ||
| National Wheat Research Program, Field Crops Research Institute, Agricultural Research Center, Giza, Egypt | ||
| Abstract | ||
| Six bread wheat ( Triticum aestivum L) genotypes were selected from previous screening trails at Sakha Agric. Res. Station based on yield potentiality and adaptability for different sowing dates. These genotypes were evaluated in field experiment under six sowing dates, planted at two-week intervals, started from October 26 in two consecutive seasons 2004/05 and 2005/06. Results indicated that sowing wheat in the last ten days of November recorded the highest number of days to heading, number of kernels spike-1 and grain and straw yields in both seasons. Meanwhile, the early or late sowing date declined the records of these characters in the two seasons. The earliest sowing date, October 26 recorded the highest number of days to maturity and heaviest 1000-kernel weight, while, delaying sowing time reduced these characters. Giza 168 was the earliest genotype in days to heading in both seasons and Line 3 was the latest one. Sakha 94 was the earliest genotype in maturity. The highest grain yield was obtained from Sakha 94 and Line 1 in the first and second season, respectively. The late genotypes in heading date were more suitable to early planting, so, Line 3 might be more adapted to early sowing. Meanwhile, Sakha 94 was more adapted to late sowing than the other genotypes. Phenotypic stability of the six genotypes across 6-sowing dates and 2-years with respect to grain yield was estimated. The regression coefficients (b1) of all genotypes were not significantly different from unity. Therefore, stability of genotypes in this case is predicted on the basis of the other two parameters, i.e., stander deviation from regression (S2d) and average yield over all environments. Line 1, Giza 168 and Sakha 94 gave the highest yield over the grand mean with the regression coefficients; 1.10, 0.99 and 0.97, respectively, and they were not significantly different from regression coefficient. Line 1 is expected to give good yield under favorable environmental conditions, where it had the highest average of grain yield and regression coefficient (b, > 1.0). Giza 168 and Sakha 94 had above average grain yield, their regression coefficients were close to unity (b = 0.99 & 0.97) with non-significant standard deviation, indicating wide adaptation and stability for grain yield across the tested environments. | ||
| Keywords | ||
| Wheat; Sowing dates; Agronomic characters; Stability parameters; Regression coefficient | ||
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