RD93 (Pum Puang Mueang Sawng Kwae), a Non-glutinous Rice Variety

Abstract

In 2019/2020 major and second rice crops in Thailand occupied paddy field of 60.11 and 6.82 million rai, respectively, of which 88 percent were rainfed areas. With rainfed rice cultivation in the lower northern region, farmers in some areas grow traditional varieties which are tall and susceptible to lodging, and having rice blast and bacterial blight epidemics that lead to yield reduction. To provide alternatives for the farmers, this research aimed at improving rice variety with short plant type, blast and bacterial blight resistance, high yield, lodging resistance and medium amylose content. Crossing was made between Mudgo/BG367-2 and Hawm Surin/SPR88096-17-3-2-2 and Phitsanulok 3 (Mudgo/BG367-2//Hawm Surin/SPR88096-17-3-2-2///PSL3) followed by F₂ to F₇ pedigree selection and rapid generation advance method to obtain a promising line, PSL04088-7-R-3-R-2-R-1-R-2-3. The research had been carried out at Phitsanulok Rice Research Center during 2004 to 2018 through the following crop improvement steps, i.e. 4-row observation, intra- and inter-station yield trials, farmers’ field yield trials, yield stability trials, evaluation on rice disease and insect pests, response to N fertilizer application, analyses for grain physical and chemical quality, milling quality and cooking and eating quality, and the farmers, consumer and rice mill entrepreneurs’ acceptance evaluation. The promising line was subsequently approved by the Varietal Releasing Committee of the Rice Department to be a certified variety, “RD93” (Pum Puang Mueang Sawng Kwae). It is a non-glutinous and photoperiod-sensitive rice with flowering date (50% flowering) around 25-30 October and harvesting date at late November. It has erect plant type, 131 cm height, moderately strong culm, green-colored leaf blade, 29.6 cm panicle length, just exserted panicle, intermediate to spreading panicle type, 184 healthy seeds per panicle (transplanting method), moderate shattering and the average farmer yield of 767 kg/rai. RD93 has straw-colored husk, white dehulled grain, slender grain shape, less chalkiness (0.43), good milling quality with 56.30 percent of whole kernel and head rice, medium amylose content (22.82 percent), soft gel consistency, medium gelatinization temperature, normal cooked rice elongation, creamy white and slightly shiny cooked rice, and soft texture and slightly sticky cooked rice. Remarkable features of RD93 are blast resistance, moderate resistance to bacterial blight, lodging resistance and high yield potential (934 kg/rai). It is recommended for rainfed paddy fields in the lower northern region where farmers require medium maturing rice varieties. Cautions for this variety are susceptible to brown planthopper and whitebacked planthopper.