Sensory quality and nutritional composition of carrot (Daucus carota L.) genotypes as affected by fertilization in production system in Cameroon

Abstract

Abstract Background Recommendations for fertilizer use in agriculture do not take into account the growing region and the source of the organic matter. In addition, vegetable growers are unaware of the quantities of fertilizer to be applied during cultivation. Accordingly, there are increasing complaints about the poor quality of the vegetables produced which is likely associated to the type and the dose of fertilizer used. Therefore, the objective of this work was to determine the probable origin of poor carrot quality in production basins in Cameroon. The factors consisted of five carrot genotypes and nine fertilizer types arranged in the field in a split-split plot experimental design. The sensory quality of the carrot samples was assessed by a quantitative descriptive test. The nutritional value was determined according to the treatments performed. Results The results of this study showed that both the sensory quality and nutritional value of carrots significantly depend on the variety, and the type and dose of fertilizer used. However, the variety New Kuroda treated with 10 t ha−1 of chicken manure and the unfertilized variety Vanessa F1 were recorded as having the best sweetness and overall acceptability scores. The best nutrient parameters such as total carbohydrate, proteins, ash, cellulose, NDF and ADF were obtained with the carrot varieties New Kuroda grown with a combination of chemical fertilizer (300 kg ha−1) + chicken manure (10 t ha−1), Pamela + unfertilized, Madona fertilized with 10 t ha−1 chicken manure, with 600 kg ha−1 chemical fertilizer + 5 t ha−1 chicken manure or not fertilized, Amazonia fertilized with 300 kg ha−1 chemical fertilizer and Vanessa F1 fertilized with a combination of 600 kg ha−1 chemical fertilizer + 5 t ha−1 of chicken manure. Conclusion Carrots with good sensory quality such as sweetness and deep orange colour were obtained with unfertilized Vanessa F1 variety. The variety Amazonia fertilized with 300 kg ha−1 chemical fertilizer provided good nutritional parameters including carotenoids, fibres, carbohydrates proteins and lipids.