Production and quality of the carrot in function of installments and nitrogen doses in coverage

Resumo

The supply of fertilizers in the appropriate period and dose is important for obtainment of a satisfactory production. The objective of this research is to study the effect of different installments and doses of nitrogen in coverage on the production of the carrot and the physicochemical characteristics of the roots. Nine treatments, resulting from a factorial of 4x2+1 (control without nitrogen fertilization), were evaluated in the randomized blocks experimental design, with four replications. The first factor were four nitrogen (N) doses in coverage (60, 90, 120 and 150 kg ha^-1) and the second were two forms of installments (three equal applications: 1/3+1/3+1/3 of the dose and one with increasing proportions: 1/6+2/6+3/6 of the dose), applied at 15, 30 and 50 days after emergence. The characteristics evaluated were the shoot height, fresh and dry shoot weight, fresh and dry root weight, root diameter and length, yield and some physicochemical characteristics of roots (soluble solids, titratable acidity, "ratio", pH, carotenoid content and reducing sugars). For most of the studied characteristics were obtained quadratic effects for N dose, with an estimated maximum yield of 117.7 t ha^-1 for the dose of 138 kg N ha^-1. For the installments, 1/6+2/6+3/6 showed higher values for the fresh weight of the shoot and root, root diameter, yield and carotenoid content than the another installment.