Morpho-agronomic Evaluation of Rice (Oryza sativa L.) Variety IR28 in Wangdue-Punakha Valley

Abstract

Rice is a staple food in Bhutan, which provides 55% of the dietary calorie supply. However, domestic rice production meets only 45% of the total requirement. One of the ways to achieve rice self-sufficiency level is to cultivate high yielding varieties, which play a crucial role in enhancing production and livelihoods of farmers. In 2008, 78 entries of rice germplasm, including IR28, were introduced from the International Rice Research Institute in the Philippines. IR28 underwent seven years of vigorous evaluation both on-station and on-farm. Onstation evaluation was done at RDC Bajo research farm followed by on-farm trials in the midaltitude geogs of Wangdue-Punakha valley. The main objective of such evaluation was to screen and select potential rice varieties for release and promotion in the country. Currently, Bhutan has only 23 released varieties and there is a need to identify more through research and extension. With emerging threats from the vagaries of climate change and associated risks, there is a need to increase the genetic base of rice in the country. IR28 was evaluated both onstation and on-farm using RCBD with three replications. IR28 was assessed as the best entry in terms of yield, grain quality, and overall farmers’ acceptance. The evaluation trials at RDC Bajo showed that it produced grain yield of 4–6 t/ha. From the agronomic, morphological, and grain quality aspects, IR28 was rated as the best variety by farmers. Therefore, IR28 is now
proposed for release in the mid-altitude regions of the country.