Identification of Suitable Irrigation Interval for Paddy Based on Growth and Yield to Adapt Water Shortage Problem in Ampara District of Sri Lanka

Abstract

Field trials were conducted at Rice Research Station, Sammanthurai during “Yala” season 2017 to evaluate the effects of irrigation intervals (7, 10 and 14 days) ongrowth and yield parameters of rice varieties Bg 250 (Short duration) and Bg 94.1 (Long duration) in order to cope with water shortage problem in irrigation schemein th study area.The trial was performed as pot experients as it was difficult control irrigation intervals in the Field. Experiment was designed as factorial treatment in randomized complete blocks design with six treatments and three replicates. The germinated seeds were established in the 40 cm diameter and 30 cm depth of 18 pots. The results showed that the Bg 250 produced 2967.30 ± 90.92 kg/ha which is 27% higher yield than Bg 94-1with the application of water at 7 days irrigation interval. The Bg 250 produced 2589.50 ± 350.83 kg/ha (18% higher yield) grain yield with the 10 days irrigation interval. Cost of irrigation was calculated as labour cost for irrigation arrangement per day and the cost of irrigation.Bg 250 was 17.6 % and 16.7% lower than the cost of Bg 94-1 when water was applied at 7 days and 10 days irrigation interval, respectively. The grain yield was significantly different between the rice varieties Bg 250 and Bg 94-1 where the Bg 250 was produced higher grain yield in all three irrigation intervals. Therefore Bg 250 can be recommended for “Yala” season in Ampara District with the application of water at irrigation intervals 7 days and 10 days interval to deal with the shortage in water that is being faced currently in Ampara district farmers now and in the foreseeable future.