Crop Performance and Water Productivity of Transplanted Rice as Affected by Seedling Age and Seedling Density under Alternate Wetting and Drying Conditions in Lao PDR

Abstract

Drought is common under rainfed lowlands in Lao People's Democratic Republic, and with the uncertain onset of rains during the wet season, delay in transplanting results in yield reduction. This study aims to explore ways to ameliorate the negative influence of delayed transplanting on rice crop. A field experiment was conducted for two wet seasons to investigate the effect of seedling age and seedling density on crop performance in terms of grain yield and water productivity. The experiment was laid out in a split-split plot design in four replicates, with seedling age as the main plot, seedling density as the subplot, and varieties as the sub-sub plot. In both years, there were significant seedling age and variety interactions on grain yield. Higher grain yields were observed with older seedlings having stronger tillering propensity. Seedling density did not affect grain yields in both years, but on grain yield components. Shorter duration variety received less supplemental irrigation than longer duration varieties. Late transplanting improved total water productivity but decreased irrigation water productivity due to harvesting delay. The total crop growth duration (from sowing to maturity) was prolonged with transplanting delay. However, the total stay of plants in the main field (from transplanting to maturity) was reduced by 3-5 d for every 10 d delay in transplanting. The results indicated that a good selection of varieties and increasing seedling density improve crop performance and water productivity with delayed transplanting.

Raising Climate-Resilient Embolden Rice (Oryza sativa L.) Seedlings during the Cool Season through Various Types of Nursery Bed Management

“…The prerequisite of a low time in raising seedlings lowered the input use in terms of manpower and irrigation supply. Additionally, early-age transplantation helps in the easy acclimatization of seedlings in the main field, and a longer duration in the nursery bed has greaterintense transplanting shock because of greater root damage probability [55]. Previous researchers also supported that younger seedlings ensured higher panicle count, grain yield and better grain quality [9,22,55].…”

“…Additionally, early-age transplantation helps in the easy acclimatization of seedlings in the main field, and a longer duration in the nursery bed has greaterintense transplanting shock because of greater root damage probability [55]. Previous researchers also supported that younger seedlings ensured higher panicle count, grain yield and better grain quality [9,22,55]. The prevention of direct evaporation from polythene-protected plots might be a reason for low water demand.…”

Water Management for Sustainable Food Production

“…Efficient water use in rice production is a prerequisite to sustaining the world's food security. The objective of Lampayan et al's (2019) [12] study of rice production systems is to test their hypothesis that a delayed transplanting strategy reduces irrigation requirements and increases irrigation water productivity. They tested the hypothesis using a field experiment conducted in two wet seasons in Lao People's Democratic Republic by evaluating the interactive effects of seedling age, seedling density, and variety on post-transplanted rice crop development (e.g., tillering propensity), grain yield, and water productivity.…”

Yield Component Compensation as Affected by Seeding Rates in Dry Direct Seeded Rice

“…When plant densities of 5 -100 plants m −2 were used, a higher grain yield was noted in favor of a greater number of plants per area (Hayashi et al 2006;San-Oh et al 2008;Nakano et al 2012). In addition, Lampayan et al (2019) reported that transplanted seedlings of 25 -75 m -2 densities produced similar grain yields in flooded fields.…”