Weather related yield constraints and optimum date of planting for rainfed rice (Oryza sativa) in central zone of Kerala

Abstract

Weather is the most determining factor in rain fed rice production. A field experiment was carried out during kharif season, 2019 at Agricultural research station, Mannuthy. The experiment was laid out in split plot design with five dates of planting i. e June 5th, June 20th, July 5th, July 20th and August 5th as main plot treatment. Two rice varieties Jaya and Jyothi was considered as sub plot design. Correlation was done between weather parameters and yield. According to correlation analysis yield was found to be significantly correlated with weather variables like maximum temperature, minimum temperature, rainfall, relative humidity, pan evaporation and bright sunshine hours. Effect of dates of planting on grain yield was found to be significant. Maximum grain yield was recorded during June 5th planting which was on par with June 20th planting. Among the two varieties yield and yield attributes recorded for Jaya was higher compared to Jaya. A higher value of maximum temperature and a lower value rain fall experienced during ripening period was found to be detrimental for yield.