Growth and Yield Performance of Inbred and Hybrid Rice Varieties as Influenced by Combined Application of Organic and Inorganic Fertilizers

Abstract

The study evaluated the effects of organic and inorganic fertilizers on the growth and yield of two lowland rice varieties; determined the proper fertilizer combination; and evaluated the profitability of rice production as influenced by the combined application of organic and inorganic fertilizers. This was laid out in split plot arranged in a RCBD design with variety and fertilizer treatments as the main plot and subplot, respectively. Results revealed that the period from sowing to heading, shoot dry weight, number of filled grains per panicle and weight of 1,000 grains were significantly influenced by the variety. The yield, yield components and harvest index (HI) were significantly influenced by fertilizer application. A significant interaction effect was noted on the period from sowing to heading as observed that inbred rice (NSIC Rc212) headed late than hybrid (TH82). Plants applied with 120-60-60 kg ha-1 N, P2O5 and K2O produced taller height, larger LAI, longer panicles, more productive tillers and filled grains, and consequently highest grain yield and HI. These plants also produced the heaviest root and shoot dry weights resulting to higher root shoot ratio compared to unfertilized plants. Highest net income was obtained in plants applied with inorganic fertilizer at the rate of 120-60-60 kg ha-1 N, P2O5 K2O due to high grain yield. Irrespective of fertilizer treatments, inbred rice was more profitable than hybrid. Highest production cost was incurred in plants applied with pure organic fertilizer due to the high cost of the material.