Understanding the leaf rolling of paddy and exploring its management options under aerobic rice

Rice is a staple food in the diets of more than half of the world's population. With India's irregular rainfall patterns and continual environmental anomalies, particularly in Kerala, the identification of climate-smart management practices which can withstand drought is critical. In this context, atrial was conducted in the experimental plots to evolve effective water and nutrient management practices under aerobic rice in lateritic soils of Kerala. However, during the experiment in a few treatments, rolling of leaves was observed, and when explored for the reasons, it was due to soil moisture deficit and plant water stress. When compared to other crop species, rice is highly vulnerable to water deficit. In this regard, an attempt has been made to study the leaf rolling pattern in aerobic rice and how this can be managed with a few soil amendments so that rice productivity can be sustained. The results showed that plant growth parameters, relative water content (RWC), membrane leakage (ML) and spectral signatures were significantly affected by the leaf rolling. It was found that leaf rolling affected plants have less RWC and higher ML and are under drought stress. Pearson correlation analysis showed a strong positive correlation (P < 0.05) of key spectral indices with other physiological traits such as RWC and negatively correlated with ML. Moisture absorbent media such as cocopeat, compost, saw dust and vermiculite were attempted as management strategies to overcome this stress. Results showed that among the absorbents attmepted, cocopeat was found to be better in managing the stress. These results suggest that for aerobic rice under lateritic soil, moisture absorbent media such as cocopeat, has to be incorporated so that it can reduce the rate of leaf rolling thereby sustaining the paddy yield.