Morphological, physiological and rice yield in lowland and upland under drought stress

Drought is a significant factor contributing to the reduction in rice production. Therefore, this study aimed to examine the morphological, physiological, and yield responses of rice under lowland and upland planting methods subjected to drought treatment. The experiment was conducted in a greenhouse using a split-plot design with 3 replications. The main plot was water regime treatments, while the subplot was rice varieties. Water regimes included 4 levels, namely lowland planting method (T1), lowland planting method with drought treatment (T2), upland planting method (T3), and upland planting method with drought treatment (T4). Drought stress treatment was applied at 55 DAP (days after planting) by stopping watering until the plants showed a leaf rolling score of level 9 (leaf fully rolled) based on standard evaluation system for rice by IRRI. The plant materials used were 4 rice varieties, such as IPB 3S, Inpago 10, IPB 9G, and IR 64 respectively. The results showed that water regime treatments led to reduced plant height, root volume, and root weight. In upland planting method, IPB 9G produced the longest root length of 78.0 cm. Furthermore, the number of productive tillers and root length showed no significant differences under the treatment. Chlorophyll content, stomatal conductance, and intercellular CO2 levels were significantly affected by drought. Flowering age, panicle length, grains per panicle, and the weight of 100 grains were also affected. Based on observation, Inpago 10 had a faster flowering age of 90.33 DAP. The highest panicle length, grains per panicle, and rice yield per pot were produced by IPB 9G, suggesting the potential for cultivation in lowland, upland, and drought-affected environments.