Genetic Gain in Yield and Yield Attributing Traits of Rice under Upland Ecosystem of Fogera, Northwest Ethiopia

Abstract

Evaluation of varieties from different years in a common environment is one of the most direct methods used to estimate breeding progress. Twenty upland rice varieties released in Ethiopia from 1998 to 2016 were evaluated at Fogera National Rice Research and Training Center in 2017 cropping season to estimate the amount of genetic gain over the years. The varieties were laid out in a randomized complete block design with three replications. Analysis of variance revealed significant differences among varieties for all traits. Grain yield was increased from 2.76 t ha-1 to 4.86 t ha-1 over the past 18 years. The average rate of increase in grain yield of upland rice per year, estimated from the linear regression on year of variety release, was 0.044 t ha-1 with a relative genetic gain of 1.59% year-1, although non-significant. The study showed significant improvements in grain-filling period, panicles length and number of filled-grains panicle-1. Significant reduction was also observed in days to heading and thousand-seed weight. No marked changes were observed in grain yield per plant and biological yield, number of fertile tillers, plant height and days to maturity over the 18-year period.