Abstract:
Carrot (Daucus carota subsp. sativus) is an important vegetable crop in Ethiopia. In many areas of the country, the rain fed season constitutes much of the area under carrot production. Despite areas increase, the productivity and production is much lower in the country. Optimum nutrient management and inappropriate plant population are some of the major yield limiting factors for successful carrot production. Northeastern Ethiopia has suitable agro-climatic condition for carrot production. However, carrot production packages, including its NPS fertilizer rate and appropriate spacing are not yet determined in the study area. Therefore, this experiment was conducted at Tehuledere district from August to December 2018 to determine optimum blended NPS fertilizers rate and an appropriate plant spacing for yield components and root yield of Nantes carrot variety. The treatments were consisted of five blended NPS fertilizer rates (0, 50, 100, 150, and 200 kg ha-1) and three intra row plant spacing (3, 5, and 7 cm) with constant inter row spacing of 25 cm. Data were collected on growth, yield attributes, yield and quality parameters. Analysis of variance revealed that plant height, number of leaves per plant, fresh weight of leaves, root length, root diameter, core diameter, fresh weight of root, dry weight of root and fresh biomass yield, root texture, total soluble solid, pH, and titrable acidity were significantly (p<0.05) influenced by main effect NPS fertilizer rates and intra row spacing but days to maturity and root shape significantly (p<0.05) affected only by main effect intra row spacing. Yield per plot, marketable root yield and total yield were significantly (p<0.05) influenced by the interaction effect of NPS rates and plant spacing. The highest total carrot yield (57.00 t ha-1) and marketable carrot yield (55.00 t ha-1) was recorded from application of 200 kg ha-1 NPS and 3 cm intra row spacing. Based on economic analysis the highest net benefit was obtained from carrots supplied with 200 kg NPS ha-1and planted in 3 cm intra row spacing. However highest marginal rates of returns was obtained from carrots received 150 kg NPS ha-1 in 3 cm intra row spacing. Based on the results of the present study, NPS fertilizer at the rate of 150 kg ha−1 with 3 cm intra row spacing could be recommended for the production of carrot in the study area since the rate resulted the highest marginal rate of return. However, as the results were limited to one season, multi-seasonal studies are further recommended.
