RESUMO O nitrogênio (N) é o segundo nutriente mais demandado pela melancia e o que mais limita o seu crescimento e afeta a qualidade quando em deficiência. Foi avaliada a concentração de N no solo (N-nitrato), o teor de N na planta e sólidos solúveis da melancia 'Top Gun’ no Brasil, com seis doses de N (0, 50, 100, 150, 200 e 250 kg ha-1). Os valores de N-nitrato e N foliar aumentaram linearmente com as doses de N. Número de frutos total e comercial, massa de frutos total e comercial e produtividade total e comercial apresentaram efeito quadrático. A maior produtividade total e comercial foram obtidas com 187 e 184 kg ha -1 de N, respectivamente. As doses de N não influenciaram no teor de sólidos solúveis. | ABSTRACT Nitrogen (N) is the second most important nutrient required by watermelons that can limit their growth and affect fruit quality when deficient. We evaluated the soil (N-nitrate) and foliar N contents and soluble-solid content of the watermelon 'Top Gun' in Brazil at six rates of N fertilization (0, 50, 100, 150, 200 and 250 kg ha-1). N-nitrate and foliar N levels increased linearly with rate. Number of total and marketable fruit, weight of total and marketable fruit and total and marketable yields varied quadratically with rate. N rates of 187 and 184 kg ha-1 produced the highest total and marketable yields, respectively. The rate of N fertilization did not significantly affect total-solid content.

Nitrogen (N) is the second most important nutrient required by watermelons that can limit their growth and affect fruit quality when deficient. We evaluated the soil (N-nitrate) and foliar N contents and soluble-solid content of the watermelon 'Top Gun' in Brazil at six rates of N fertilization (0, 50, 100, 150, 200 and 250 kg ha-1). N-nitrate and foliar N levels increased linearly with rate. Number of total and marketable fruit, weight of total and marketable fruit and total and marketable yields varied quadratically with rate. N rates of 187 and 184 kg ha-1 produced the highest total and marketable yields, respectively. The rate of N fertilization did not significantly affect total-solid content.