The Influence of Seed Rate and Inter-Row Spacing on Seed Yield and Yield Attributes of Black Cumin in Arsi Highlands, Ethiopia

Abstract

Black cumin is the major and the most important spice in Southeast highlands of Ethiopia. However, the yield of the crop is very low mainly due to lack of optimum plant density. A field experiment was done with the objective to assess the influence of different seed rates and inter-row spacing on yield and yield attributes of black cumin at Kulumsa. This experiment was done in the cropping years of 2017, 2018 and 2019 at Kulumsa Agricultural Research Center, Southeast Ethiopia. Twelve treatment combinations of four seed rates (5 kg ha^-1, 10 kg ha^-1, 15 kg ha^-1 and 20 kg ha^-1) and three inter-row spacing (20 cm, 30 cm and 40 cm) were studied on a black cumin variety – 'Aden', which was laid out in a randomized complete block design (RCBD) with factorial arrangement in three replications. The interaction effect of seed rate and inter-row spacing was not statistically significant (P > 0.05) on all growth and yield parameters. However, the main effect of seed rate was significant (P < 0.05) on most of the parameters studied while inter-row spacing was significant only on days to emergence and plant height. Yield and yield attributing factors such as number of primary branch plant^-1, number of secondary branch plant^-1, number of pods plant^-1 and seed yield ha^-1 (kg) were significantly influenced by the seed rate. Seed yield increased from 462 kg ha^-1 to 634 kg ha^-1 as seed rate increased from 5 kg ha^-1 to 20 kg ha^-1 and showed a decrease in yield from 601 kg ha^-1 to 507 kg ha^-1 as inter-row spacing increased from 20 cm to 40 cm although it was not significant. Hence, 15 kg ha^-1 seed rate and 30 cm inter-row spacing could be recommended for optimum black cumin production in the study area. However, further research needs to be undertaken in different black cumin producing areas of the country on recent varieties to achieve the optimum seed rate and inter-row spacing with information related to cost of production for better recommendation.

Keywords: competition, crop management, Nigella sativa, plant density

DOI: 10.7176/JBAH/11-1-04

Publication date: January 31^st 2021