Influence of Maturity Duration on Grain Yield of Rice under Direct-seeded Condition in the Tropics

Abstract

Background: The optimum maturity duration for maximum grain yield of non-photosensitive rice (Oryza sativa) under direct-seeded condition in the tropics was studied. Information on such studies conducted using near-isogenic rice lines are lacking. Change in yield with maturity duration was explained using yield components. Methods: The experiment was conducted in the dry zone of Sri Lanka over two seasons namely dry and wet during 2021 and 2022. Non-photosensitive near-isogenic rice lines that are varying in maturity duration from 80 to 120 days but with 94.0% genetic uniformity were used as simple treatments in the study. Pre-germinated seeds of isogenic lines were direct-seeded in the experimental plots. Result: The most appropriate relationship between maturity duration and grain yield was cubic and the optimum maturity duration for the maximum grain yield was falling within 105 to 111 days in both dry and wet seasons under direct-seeded condition in non-photosensitive rice in the tropical climate. Number of panicles/m2 and number of spikelets/panicle influenced to change the grain yield of rice with the change in maturity duration.