FAZU/Faculdade de Agronomia e Zootecnia de Uberaba.

ABSTRACT: Fertirrigation of melon still presents problems in relation to the type of the fertilizer used, mainly the biofertilizers. This experiment, installed in Uberaba, MG, Brazil, in a plastic module greenhouse of 768 m 2, tested treatments consisting of the conventional mineral fertirrigation and the organic fertirrigation, using two frequencies: daily and weekly. The best yields were obtained with daily fertilizer application, with superiority in relation to biofertilizers, with yield of 45.5 t ha-1 of fruit. This value was higher as compared to chemical products, that lead to a yield of 42.4 t ha-1. The weekly fertigation had lower productivities, and in this case, the biofertilizers also overcame the mineral, on the average 2.0 t ha-1. The best melon soluble solids values were obtained for the daily application of fertilizers, and the best treatment (P < 0.05) was the organic daily fertigation, with values of soluble solids content of 13.60 ° brix, followed by the daily chemical fertigation, with values of 12.52°. On the average, the amounts of soluble solids in melon were superior to the average found for Brazilian melons. Differences were not verified among the treatments for the variables pulp thickness and fruits pH. Regarding the peel thickness, the application of organic fertilizer sources presented a slight superiority in relation to chemical fertilizer treatments. No differences were verified among treatments in relation to the amount of fruits protein