Evaluation of seeding rates of rice nursery on seedling vigour and its effect on crop productivity under system of rice intensification

Four seeding rates (25, 30, 35 and 40 g/m2) of rice in nursery were tested for seedling vigour recorded at 10, 17 and 24 DAS at Malan during 2013 and 2014. The seedling vigour so obtained in nursery was subsequently evaluated in field during kharif 2013. Thus twenty four treatments comprised of combinations of three seedling ages (10, 17 and 24 days) and two spacings (20 × 20 cm and 20 × 15 cm) in main plots and four seedling vigour from four seeding rates (25, 30, 35 and 40 g/m2) in sub plots were evaluated in split plot design. Seedling shoot length under all seeding rates (25-35 g/m2) was significantly higher compared to check (40 g/m2) during 2013. In the next year, shoot and root length (30-35 g/m2), tiller per seedling and leaves per seedling (25-30 g/m2) of 24 days nursery was significantly higher over check (40 g/m2). Plant height, tillers, leaves and dry matter accumulation were significantly higher when younger seedlings aged 10 and 17 days were used. The crop raised using 10 days old seedlings matured 3-5 days earlier than 24 days old seedlings. Wider spacing resulted in more plant height, tillers, leaves and dry matter accumulation. Seedlings from 25, 30 and 35 g seed/m2 resulted in significantly taller plants than 40 g/m2. The seeding rate, seedling age and plant spacing did not significantly influence rice productivity thereby permitting flexibility to the rice farmers in the adoption of these factors.