Effects of number of seedlings on growth, yield, cost and benefit of 2 rice genotypes in translated fields

Abstract

This experiment was conducted during the dry season of December, 2010 until May, 2011, in the farmer’s irrigated rice fields at Suan Luang village, Pongpawaey Subdistrict, District of Den Chai, Phrae province in Thailand to assess plant growth, yield, cost and benefit of RD14 and San-pah-tawng1 rice genotypes grown in transplanted fields under crop establishment methods using 1, 2, 3, and 4 seedling(s)/hill.  Plant height of RD14 rice genoype was significantly taller than San-pah-tawng1 rice genotype. Grain yield of RD14 rice genotype was significantly higher than San-pah-tawng1 rice genotype; mainly due to RD14 rice genotype having had higher filled grain number per panicle and harvest index. Grain yield was, however, influenced by crop establishment method and rice genotype as RD14 rice genotype grown under crop establishment method using 1 seedling/hill yielded significantly higher than the controlled treatment (crop establishment method of RD14 rice genotype using 4 seedlings/hill). The two rice genotypes grown under crop establishment methods using 4 seedlings per hill had higher costs of production than other crop establishment methods using lesser number of seedlings per hill, mainly due to the higher use of seed rate per hectare for seedling preparation that raised the cost of production. The seeds’ cost for seedling preparation for RD14 rice genotype under crop establishment methods using 1 seedling/hill could be saved by about 75% compared to that crop establishment method using 4 seedlings per hill. The net profit derived from RD14 rice genotype grown under crop establishment methods using 1 seedling/hill was considerably higher by 46% than of the controlled treatment. Therefore, the crop establishment method using 1 seedling/hill for RD14 rice genotype was the most feasible for investment in transplanted rice production indicated by the highest value of benefit-cost ratio (B/C ratio is 1.17) compared to the rest of the treatments.