抄録
Indigenous glutinous rice varieties have recently been replaced with an improved variety, RD6, in Northeast Thailand. The good cooking quality and high yielding ability of RD6 have induced many farmers to plant it in their paddy fields. Productivity per planted field in the surveyed village has increased due to the planting of RD6 as well as the adoption of power tillers, subsidiary irrigation and fertilizers. This variety, a panicle-number type, tends to increase yields more easily than the old varieties when planted densely in the appropriate season with judicious fertilizer management under conditions of no drought and no inundation. Nevertheless, the instability of rice production caused by flood and drought is yet to be resolved in rain-fed cultivation. Planting RD6 in an unsuitable area normally fails to produce a good harvest. More improved varieties for rain-fed cultivation should be released in this region.