Yield Effects of Plot-Level Korra Tef (Eragrostis tef) Seed Rate in Central Ethiopia: Application of the Dose-Response Model

Abstract

Ethiopia's government and development practitioners have encouraged the utilization of improved tef (Eragrostis tef) varieties to increase crop production. However, apart from introducing improved tef varieties, more needs to be known about the plot-level yield effects of adopting these varieties. Based on this, the current study sought to investigate the yield effects of plot-level tef seed rate in Central Ethiopia, focusing on the Korra tef variety. Two Hundred Twenty One (221) Korra tef producers were selected using multi-stage stratified sampling technique. Survey data were gathered from these respondents using a questionnaire, and interview guides were used to gather qualitative data from the key informants. The yield outcomes of seed rate users categorized as users below, within, and above the recommendations were examined using one-way ANOVA. The F-test results indicated disparities in yield across the three types of seed rate users. The impacts of seed rate on yield were examined using the Dose-Response Model, which was applied to five seeding rates (12, 14, 16, 18, and 20kgha-1). According to a Dose-Response analysis, the highest average tef yield was attributed to a seed rate of 20 kgha-1, slightly higher than recommended. The findings revealed a significant correlation between the utilization of the recommended Korra seed rate and increased crop productivity among growers. It is evident that encouraging farmers to solely use improved seed varieties is insufficient. Rather, the focus should be on promoting the utilization of the recommended seed rates. Furthermore, a reassessment of the ideal Korra tef seed rate for the study area is warranted, considering the observed benefits in productivity as farmers approached the utilization of the recommended rate.