From combined analysis over the years, it was observed that varietal difference in plant height, days to anthesis and maturity, biomass, grain yield, HI, thousand grain weight, spikes/m2, number of grains/m2 and grains/spike were significant (Table 3). A variety Weaver was shortest (77 cm) and Pastor and Baviacora 92 (104 cm) were tallest followed by Rayon 89 (100 cm). Plant height of other varieties was around 90 plus or minus 5 cm. Among the varieties under study, HD 2329 was early in nature and took 75 days till anthesis, whereas others extruded their anthers in approximately 90 plus or minus 2 days after emergence. Similarly, varieties HD 2329 and Munia/Kauz matured in 124 and 126 days, respectively whereas others showed their physiological maturity in 132 to 135 days after emergence. Therefore, it can be considered that varieties under investigation were of similar maturity group except HD 2329 and Munia/Kauz.
From pooled analysis, variety advanced line, Super Seri named in 1999 recorded significantly higher grain yield (9968 kg/ha) than other varieties and this genotype also yielded 774 kg/ha more in absolute term, which comes to be 8.4 % higher, as compared to second highest yielding cultivar WH 542 (9194 kg/ha). Super Seri also exhibited 23.7 % higher gram yield than the lowest yielding variety Pavon 76 (8056 kg/ha) released in 1976. Varieties like Seri 82, Munia/Kauz, Bacanora 88, Weaver, Baviacora 92, WE 542, UP 2338 and PBW 343 displayed non-significant difference in grain yield, which was in the range of 8800 to 9200 kg/ha. At CIMMYT, in a historic set of 8 cultivars was studied for six years by Sayre et al. (1997) and they reported about 27 % increase in grain yield from Pitic 62 (6680 kg/ha) released in 1962 to Bacanora 88 (8475 kg/ha) released in 1988. While, in the present investigation, yield potential approached to 10 tonne/ha. Even Super Seri gave 9.9 % higher gram yield than Bacanora 88. The estimation of yield potential without netting is a complex phenomenon. It is limited by lodging if irrigation is given during late milk stage, and if not then yield is reduced due to reduction in grain weight (Hobbs et al. 1998). Super Seri (containing Lr19 and Lr26 ) recorded 10.4 % higher grain yield over Seri 82 (Lr26 gene). This finding was in corroboration with Singh et al. (1998) who have conducted experiments at CIMMYT with the use of near isogenic lines and reported 8.2 % increase in grain yield due to Lr19 gene.
Super Seri also exhibited the second highest biomass (18976 kg/ha) and HI (0.462) after Star (19177 kg/ha) and HD 2329 (0.469). The lowest biomass was exhibited by Indian variety HD 2329 (16457 kg/ha), which probably lead to higher HI. In contrast, lowest HI (0.390) was exhibited by Star despite highest biomass production. Varieties Baviacora 92 (47.55 g) and PBW 343 (47.13 g) recorded significantly higher thousand grain weight as compared to other genotypes. The difference between these two varieties is not significant. On the other hand, variety Weaver and WH 542 weighed lowest thousand grain weight (35.3 g). Among the varieties under study, it was observed that genotypes possessing lower thousand gram weight have shown higher number of spikes/m2 and vice versa. The number of productive tillers/m2 was lowest in CPAN 3004 (397) and highest in Weaver (696), which was significantly higher than other varieties. The number of grains/m2 was product of numbers of spikes/m2 and grains/spike, and it ranged from 16555 (Pastor) to 22960 (WH 542). The latter variety showed highest grains/m2 due to lowest thousand grain weight.
Variety Munia/Kauz recorded maximum grains/spike (48.2) followed by Super Seri (47.3) and Bacanora 88. On the other hand, Pavon 76 recorded lowest number of grains/spike (31.8).
The effect of cultivation year was significant for biomass, grain yield, HI, number of grains/m2 and grains/spike, and 1998-99 crop cycle performed higher grain yield as compared to 1997-98. This was possible due to favorable condition during subsequent crop cycle than previous one. From mean of two years, grain yield correlated maximum with HI (r = 0.62, P<0.05) and number of grains/spike (r = 0.60, P<0.05). Therefore, it could be said that increase in gram yield was cumulative effect of the yield attributing parameters.