| Results and Discussion Estimates of mean values for grain yield per m2, plants per m2, spikes per m2, seeds per m2, days to heading and harvest index from different between and within row spacings are presented in Table 1. Data reveal that maximum yield was reached by all cultivars when spaced 1 cm apart in rows which were spaced 15 cm apart. This represents a seeding rate of 667 seeds per m2. Yield was not significantly reduced, however, when plants were spaced 2 cm apart in 10 cm rows. This is equivalent to a seeding rate of approximately 500 seeds per m2. In other words highest yields were obtained from the parcels with 500-667 plants per m2. Very similar results have been obtained by TSONEV & MOSKOV (1975) with 500-600 seeds per m2 and SIMEONOV & KASIMOV (1978) with 600 seeds per m2. Row spacings and seeding rate had a significant effect on grain yield (Table 2). With decreasing row spacing grain yield increased upto optimum. Likewise highly significant (P>.01) differences among cultivars for the metrical traits were also observed. In addition a significant cultivar x row spacing interaction for yield was observed similar to HARRINGTON (1941) and STOSKOF (1967) with winter wheat. Further more C x S, R x S and C x R x S interactions were significant. A cultivar x density interaction had also been reported by SAKAI & IYAMA (1966) and RULE & FIDDIAN (1974). The number of plants per unit area is a direct, positive linear function of seeding rate. Row spacing and seeding rate had a definite effect on number of plants per unit area. DARWINKEL et al.(1977) reported a parallel increase in plants per m2 with increase in seeding rate. Consistent changes in the number of spikes per m2 with changes in row spacing and seeding rates were observed. C x R, C x S, R x S and C x R x S interactions were significant for this trait. Plant density had a marked effect on number of seeds per m2. Row spacing, seeding rate and their interactions with cultivar had significant effects on number of seeds per m2. Seed number per unit area increased with increasing density upto the optimum plant density, then it showed a tendency towards decreased seed number at the above optimum density (Table 1). Grain production is greatly influenced by the amount of carbohydrates available for ear development. A very distinct decline in crop growth for the higher populations during the later stages of ear development was reported by PUCKRIDGE & DONALD (1969), resulting in reduced amount of carbohydrates available for ear development, a reduction in number of grains per unit area and a subsequent decrease in final grain yield. |
| <-- Back | | | --> Next |