ROLE OF SEEDLING AGE ON GROWTH AND RICE YIELD 1- GROWTH PROPERTIES AND BIOLOGICAL YIELD

Abstract

A field experiment with two factors was carried out at the Rice Research station in Al-Mishkab during 2008 and 2009 seasons to study the effect of seedling age on growth and biological yield of some rice cultivars.The design was split plot with RCBD arrangement in four replicates. The statistical analysis showed that the early seedlings ages i.e.(20 and 27)days led to a significant increase in the panicle length ,flag leaf area, and biological yield compared with two late ages (34 and 41) days,Treatment of seedling ages (20 and 27) days gave highest value than other treatments ,of panicle length (23.2,23.3 cm),(21.7, 22.1 cm), flag leaf area (29.6,30.3 cm2),(21.4 , 20.5 cm2), biological yield (9.87 , 10.06 tn.ha-1), (9.91 , 9.76 tn.ha-1) in both seasons respectively , However a significant reduction of number of days from sowing to 50% anthesis (106.6, 108.0 day) ,(110.6 , 110.7), number of days sowing to physiological maturity(139.3, 140.8 day) ,(139.5, 139.6 day) in both seasons respectively , was found in these two early ages .Seedlings ages had no significant effect on plant height, in both seasons.Cultivars showed significant differences in most studied characters. local cultivar Anber33 gave highest values number of days from sowing to 50% anthesis (111.4 , 113.6 days), number of days sowing to physiological maturity(143.9,141.6days), plant height(139.5, 100.2 cm), panicle length (26.5,25.2cm), flag leaf area(37.4 , 22.1 cm2)in both seasons respectively., biological yield (10.32 tn.ha-1 )in first season. .