Response of modern varities of rice to nitrogen in kole lands

Abstract

An experiment was carried out in Kole lands during the Kole season of 1985 (December-January to March-April) to ascertain and compare the nutritional requirement of short duration rice varieties and pre – release culture 10-1-1. The treatments consisted of factorial combination of 3 varieties ( Jyothi, Culture 10-1-1 and Triveni) and 5 levels of nitrogen (50,70,90,110 and 130kg N ha-1) in Randomised Block Design, replicated thrice. It was found that the pre-release Culture 10-1-1 had significantly higher plant height, tiller number, leaf area index, dry matter production, number of panicles per m2 and thousand grain weight over other varieties. Triveni recorded the highest filled grains per panicle and weight per panicle. There was no variation in grain yield among the cultivars tested. Culture 10-1-1 registered the highest straw yield and nutrient uptake. Culture 10-1-1 also recorded the highest net income over the varieties tested. Application of nitrogen increased the vegetative characters and yield attributes of rice viz., plant height, tiller production, number of panicles per m2, panicle length, panicle weight, filled grains per panicle and thousand grain weight. The highest grain yield and net income was obtained by Jyothi at 110 kg N ha-1 and that for culture 10-1-1 and Triveni at 90 kg N ha-1. Straw yield and dry matter production were increased upto 110 kg N ha-1. The uptake of nutrients were also influenced positively by nitrogen fertilization. The per day production of Jyothi, culture 10-1-1 and Triveni was found to be 42.65, 51.63 and 49.88 kg, respectively at 90 kg N ha-1. The present investigation revealed that the optimum level of nitrogen fertilization to be 103.74, 97.48 and 93.07 kg ha-1 for Jyothi, Culture 10-1-1 and Triveni, respectively. It was also observed that the field duration of culture 10-1-1 was only 77 days compared to that of 79 and 91 days of Triveni and Jyothi respectively. Benefit cost ratio was highest for Culture 10-1-1 thus indicating the scope of popularizing this cultivar as a short duration variety in Kole land.