Vol. 14 No. 3
Management of weedy rice (Oryza sativa f. spontanea) by enhancing rice competitiveness
Author(s): K. Anjali, M. Ameena and N. Jose
Abstract: Of late, weedy rice (Oryza sativa f. spontanea) has emerged as a major weed in the traditional and nontraditional rice belts of Kerala. The objective of the study was to investigate the possibility of increasing crop competitiveness to weedy rice by adopting high seed rates of 100,120 and 140 kg ha-1along with two priming techniques viz., water and 2.5% KCl. Among the priming methods tested, hydropriming showed superiority over hardening with 2.5% KCl. Number of grains panicle-1, chaff percentage, grain and straw yield were significantly influenced by high seed rate (100 or 120 kg ha-1) along with hydropriming. Seed rate of 100 kg ha-1 along with hydropriming recorded the highest number of grains (120.02 and 121.76 respectively) per panicle followed by seed rate of 120 kg ha-1 with hydropriming. Better crop stand from hydroprimed seeds sown at 120 kg ha-1resulted in rapid canopy development and gave preliminary advantage to rice plants over weedy rice.Weedy rice count and dry weight showed a decline on sowing of hydroprimed seeds at 100 or 120 kg ha-1, with weed control efficiencies of 52 and 51per cent respectively. The study revealed a positive relation between rice competitiveness and hydropriming of seeds upto 120 kg ha-1. While yield increase of 10 per cent was recorded for hydroprimed seeds at 120 kg ha-1, yield reduction of 39 per cent was recorded at 140 kg ha-1. Hydropriming of seeds at a rate of 100 or 120 kg ha-1 followed by pregermination could be recommended as one of the management practices for enhancing rice competitiveness to manage weedy rice infestation in wet seeded rice.