Evaluation of Rice Landraces for Nitrogen Use Efficiency on Soil of Toje Series

Abstract

To ameliorate challenges of environmental pollution due to over-use of nitrogen fertilizer, juxtaposed with soil-nitrogen depletion as a limitation to subsistent farming, utilizing varieties responsive to minimal application of fertilizer is of priority. The goals of the study were to: identify genotypes that are nitrogen use efficient, assess genotypic variations including relationship and heritability of yield related traits and nitrogen use efficiency components. Twenty rice landraces with two nitrogen levels (0 and 50 kg/ha) replicated thrice in pot and field experiments were conducted. The experimental design for pot experiment was completely randomized design in a factorial arrangement while split plot design was used for field experiment. Landraces such as GH1550, GH1801, GH1822, GH1535, GH1590, GH1515 and GH2145 were efficient and responsive to both nitrogen levels. Analysis of variance showed significant differences for filled spikelets, panicle number, panicle length, 1000-grain weight, spikelet per panicle and harvest index. Nitrogen Use Efficiency, Nitrogen Uptake Efficiency, Nitrogen Utilization Efficiency, Grain Nitrogen Concentration and Straw Nitrogen Concentration showed significant increase under 0kg/ha of N compared to 50kg/ha in both pot and field experiments. Nitrogen use efficiency correlated significantly with filled spikelet, grain yield, panicle length, 1000-grain weight and nitrogen uptake efficiency. Broad-sense heritability estimates were high for traits such as filled spikelet, grain yield, panicle number, panicle length, 1000-grain weight, spikelet per panicle and harvest index as well as nitrogen use efficiency and its components. The identified Nitrogen Use Efficient landraces have the genetic potential needed to accelerate rice improvement for increased productivity in the characteristic smallholder low input cultivation systems in Ghana.