Effect of Different Soil Amendments and season on root quality, shelf life and profitability of carrot (Daucus carota L.)

The objective for the study was to determine the effect of different rates of soil amendment and season on root quality, shelf life and profitability of carrot (Daucus carota L.) production in the transitional zone of Ghana. The experiment was laid out in a 10 x 2 factorial with treatments arranged in Randomized Complete Block Design (RCBD). The factors were ten different rates of soil amendments and two seasons. The soil amendments used were: control (T₁), 5 ton/ha poultry manure (T₂), 45-45-45 kg/ha NPK, (T₃), 5 ton/ha compost (T₄), 7.5 ton/ha compost (T₅), 10 ton/ha compost (T₆), 50 % NPK + 2.5 ton/ha compost (T₇), 50 % NPK + 3.75 ton/ha compost (T₈), 50 % NPK + 5 ton/ha compost (T₉) and 50 % NPK + 2.5 ton/ha poultry manure (T₁₀). The seasons were major and minor. There were four replications. All data collected were subjected to analysis of variance (ANOVA) using GENSTAT Version 11.1 (2008). The application of 7.5 ton/ha compost significantly showed greatest values for beta carotene, root cracking and total soluble solid. The control treatment had significantly the longest shelf life than the amended treatments. High (P < 0.05) cost of production was observed among carrot plants supplied with 10 ton/ha compost while the profit obtained was highest (P < 0.05) in the application of 7.5 ton/ha compost. With respect to season, weight loss of carrots at 15 DAH was significantly (P < 0.05) higher in the major rainy season. The minor rainy season recorded the highest levels of vitamin C. The highest profit margin was observed in the major rainy season. This study concludes that 7.5 ton/ha compost promote bigger roots, root quality and maximize profit.