Effect of row spacing and sowing rate on seed production of lucerne (Medicago sativaL.) cv. Grasslands Oranga

Abstract

Present address: Ministry of Jihad-e-Sazandagi, Tehran, Iran.Abstract The effects of row spacing (15, 30, 45, and 60 cm) and sowing rate (1, 3, 6, and 12 kg/ha) on lucerne seed yield and its components were investigated at Massey University, Palmerston North, New Zealand, over two seasons. In the first year, seed yield from the 15 cm row spacing was significantly lower than that from the 30, 45, and 60 cm row spacings, whereas sowing rate had no effect on seed yield. In the second year crop, row spacings did not significantly affect seed yield, but the seed yield from the 1 kg/ha sowing rate was significantly greater than that for other sowing rates because harvestable racemes/m 2 and thousand seed weight were significantly increased. Seed yield over 2 years of the experiment was highest at the 1 kg/ha sowing rate and for the 30 and 45 cm row spacings. However, there were no significant interactions between row spacing and sowing rate for seed yield. The average seed yield for all treatments was 127 and 187 kg/ha for the first and second year respectively. Neither row spacing nor sowing rate had any effect on the quality of harvested seed.

Using path analysis to determine lucerne (Medicago sativaL.) seed yield and its components

“…Abu-Shakra et al (1977) showed that seed yield was significantly affected by the number of forage harvests prior to seed production, and this effect was mainly associated with variation in the number of fertile stems per plant and pods per raceme. Abu-Shakra et al ( 1969) and Askarian et al (1995) reported similar effects as a consequence of different row spacing. According to Fougereux et al (1997) little is known about the factors that are responsible for differences in physiological quality between seed lots at harvest.…”

“…Taylor & Marble (1986) reported a positive correlation between seed yield and seeds per pod among environments differentiated primarily by water supply. In contrast, Askarian et al (1995) and Kowithayakorn & Hill (1982) found that the number of seeds per pod was an unimportant yield component, when the principal source for yield variation was plant density. Genter et al (1997) showed that the number of seeds per pod was significantly reduced by plant defoliation at flowering, though the effect was small (4.1 seeds versus 4.5 for the non-defoliated control plants).…”

The effect of row spacing on alfalfa seed and forage production under irrigated Mediterranean agricultural conditions

“…In Argentina, seed production is generally favoured by spacing the rows 0·8–1·0 m apart, although in the Buenos Aires province, the typical row spacing is 0·5–0·75 m Echeverría et al ., ). In New Zealand, seed yields ranged from 127 to 187 kg ha −1 and were found to be lower in the first year of production in rows spaced 15 cm apart compared with wider rows (30, 45 and 60 cm), but these effects were not seen in the second year (Askarian et al ., ). These trials, like our investigation, also combined seed and forage production.…”

“…There was no significant impact on the other yield components, namely the number of racemes per shoot, pods per raceme, seeds per pod and the seed weight (Tables and ). Quite similar results were reported for experiments carried out in New Zealand, where the plant density was shown to have a significant effect on the number of stems per m 2 and the number of racemes per stem, but not the number of pods per raceme or seeds per pod (Askarian et al ., ). The impact of stem density on alfalfa seed yield was also observed in Australia by Downes ().…”

A new procedure for evaluating lucerne genotypes for semi‐arid land in west China

“…Plant density of lucerne varied markedly with time (Willman & Gao 1996), and is known to be an important factor in population persistence (Askarian et al 1995), because competition between plants affects their ability to acquire water and nutrients. In this trial, persistence of each cultivar was defined by observing the decline in density with time.…”