PJB-2018-639
Diurnal variation in physiological responses of aerobic-adapted rice varieties under different mulching strategies
Intan Filzah Mahmod, Mohd Zuwairi Saiman, Muhamad Shakirin Mispan, Syed Shahar Barakbah and Normaniza Osman
Abstract
Rice consumes more water compared to other crops. Therefore, rice varieties that are able to adapt non-flooded (aerobic) condition could be an advantage to conserve water. Furthermore, the ground cover rice production system using mulching technique can be effectively reduced water stress for aerobic rice cultivation. In this study, the diurnal physiological responses of aerobic-adapted Malaysian rice (Oryza sativa L.) varieties MRQ74 and MR253 were investigated under different mulching strategies, i.e. plastic mulch (PM), rice straw mulch (SM), and no mulch (NM). Photosynthesis rate (A), transpiration rate (E), stomatal conductance (gs), water use efficiency (WUE) and stomatal limitation (Ls) were measured at tillering and maturation stages of the rice plants. The latter stage have shown significant differences (ANOVA, p≤0.05) on the parameters studied, in which A was highest in PM (197 µmol m-2 s-1) followed by SM (146 µmol m-2 s-1) and NM (86 µmol m-2 s-1) in MRQ74. Interestingly, the result showed a unimodal diurnal curve for A in both tillering and maturation stages, which indicates that the midday depression of A did not present. This suggests that the mechanism improves the ability of rice plant to adapt in aerobic condition. Furthermore, mulching treatments demonstrated an improved WUE on both MRQ74 and MR253 during maturation stage. At tillering stage, PM treatment increased WUE about 75% higher compared to NM during the midday. This study shows that mulching treatment such as PM and SM can be implemented to improve aerobic rice cultivation and subsequently sustaining rice production in water limited area.
To Cite this article:
Mahmod, I.F., M.Z. Saiman, M.S. Mispan, S.S. Barakbah and N. Osman. 2020. Diurnal variation in physiological responses of aerobic-adapted rice varieties under different mulching strategies. Pak. J. Bot., 52(6): DOI: http://dx.doi.org/10.30848/PJB2020-6(14)
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