D. K. Kundu

Evaluation of planting methods in irrigated rice

This experiment was done to assess the effect of different direct seeding methods and transplanting of rice (Oryza sativa L.), cv. Naveen on growth, grain yield and its yield components. The water-use efficiency of the production systems, comparative weed growth as well as labour requirements under each method was also studied. The different direct seeding methods of planting like dry seeding by broadcast (DSB), wet seeding by broadcast (WSB), wet seeding by broadcast followed by beushening (WSBB), wet seeding in line (WSL) and wet seeding in spots (WSS) were compared with the traditional transplanting (TPR) method. WSS gave significantly higher yield (11.8%) compared to TPR due to higher tillering, more panicle, and better grain filling. Weed population under DSB, WSB, and WSS were 5, 4, and 2 times more than that under TPR, respectively. Total water requirement for growing rice crop under transplanting, wet seeding and dry seeding methods of planting were 1041.2, 941.5 and 915.0 ha-mm, respectively. Water use efficiency (WUE) was lowest under dry seeding and highest under wet seeding in spots. WSL and WSS showed 9.7 and 24.0% higher WUE, respectively, than traditional TPR method. However, commonly adopted wet seeding method, i.e. wet seeding by broadcast (WSB) showed 10% less WUE than TPR. Wet seeding reduced 5-20% labour requirements compared to TPR. In lines and spots seeding more labourers were required for the sowing, but weeding was found easier and less labour intensive in these methods. The labour requirement of wet-seeded and dry-seeded rice cultivation was also found less coinciding with the peak demand of labourers during the transplanting season. The results clearly indicate that wet seeding spot method of rice planting is an improved method that gives higher yield with less requirement of water and labour and easy weed management than the existing methods.