Assessing the Yield of a High Yielding Rice Variety, Byaw Htun, Planted Using the Cut-stem Transplant Method and Cultivated in a Deep-water Area, Bago Region, Myanmar

Abstract

Among the five rice ecosystems in Myanmar, submerged and deep-water areas occupy 13.5% of the total cultivated area. If flooding occurs, most rice varieties elongate and lay flat after the water recedes. In such a situation, the lodged stems are cut and transplanted without roots. This cut-stem transplant (CST) method is practiced locally in Ywa Houng village, Thanatpin Township in the Bago Region, using deep-water rice (DWR) varieties such as Pawsan and Yoesein in deep-water areas. However, a high yielding variety, Byaw Htun, is cultivated in the shallow-water areas by using direct seeding (DS) or the normal transplanting (NT) method. Unusual levels of flooding in 2018 resulted in almost all of the fields being subject to deeper water conditions than normal in Ywa Houng village. The highest flood level occurred on 19th July, with a 45cm depth recorded, in what is normally a shallow area (normally less than 25cm depth) and the flood peaked for about 25days. Hence, transplanting of Byaw Htun was delayed until the 10% heading stage in the nursery. Thus, farmers tested the CST method in place of NT method in Byaw Htun. This study examined to clarify the growth and yield of CST method for the Byaw Htun variety. Byaw Htun CST plants exhibit plant growth and yields comparable to those of DS plants. In addition, the yield of Byaw Htun CST was similar to, or higher than those of Pawsan and Yoesein CST. However, the harvesting of Byaw Htun CST took place far later than that of DS areas. Consequently, it was found that CST can be applied for Byaw Htun varieties when the plants were damaged by flooding, but due to delays in harvesting, the application of this method should be considered in relation to any subsequent crops to be cultivated.