ASSESSMENT OF RICE VARIETIES FOR SEMI-DRY CULTIVATION IN THE SOUTHERN AGRO-CLIMATIC ZONE OF TAMIL NADU

Abstract

Rice production under semi-dry, rainfed conditions is frequently affected by limited and variable soil moisture. An on-farm field experiment was conducted in Piranthamangalam village, Ilayangudi block, Sivaganga district, Tamil Nadu, during the rabi seasons of 2022–2023 and 2023–2024 to compare the performance of five rice variety and nutrient-management treatments under semi-dry cultivation. The experiment comprised five treatments and five replications in a randomized block design: BPT 5204 under farmers’ practice (T1); CO 55 with Azophos and ZSB14 (T2); RNR 15048 with Azophos and ZSB14 (T3); CO 51 with Azophos and ZSB14 (T4); and Jothi with Azophos and ZSB14 (T5). Growth, maturity, grain-yield and economic parameters were recorded. Treatment T2 recorded the highest plant height (112.7 cm), number of tillers per plant (32) and grain yield (58.3 q ha−1), representing an 18.5% increase over the farmers’ practice (49.2 q ha−1). Treatment T4 recorded the shortest time to maturity (110 days). The highest reported net return (Rs. 59,488 ha−1) and benefit cost ratio (2.78) were also recorded for T2. Under the conditions of this on-farm evaluation, the CO 55-based treatment recorded the highest grain yield and reported economic return. These findings indicate the potential of this treatment for semi-dry rice cultivation in the study area; validation across additional locations and seasons is required.