Irrigation frequency in melon crop cultivated in sandy soil

The objective of this work was to evaluate the effect of five irrigation fr equencies in the productivity and efficience of water use of melon crop cul tivated under fertirrigation by drip irrigation in a sandy soil of the Coas t Plains of Piaui, Brazil. The experiment was allocated in a randomized com plete block design, with five treatments and six replications. The treatmen ts were: F-1, F-2, F-3, F-4 and F-5, irrigation frequency of 0.5, 1, 2, 3 a nd 4 days, respectively. The irrigation frequency affected the marketable a nd total yield of the melon crop. The highest total (70.73 t ha(-1); 77.99 t ha(-1) and 64.21 t ha(-1)) and marketable (62.20 t ha(-1); 63.88 t ha(-1) and 53.67 t ha(-1)) yields were obtained with the frequencies of 0.5 and 1 day, respectively. It was observed that for the leastest frequent of water applications there was a significative reduction (P<0.01) of the marketabl e and total fruit yield of melon crop. The average fruit weight was not aff ected by the frequency of water application. The highest and the lowest eff iciency of water use, 24.40 kg m(-3) and 14.14 kg m(-3), were obtained with the frequencies of F-1 and F-5, respectively. The irrigation frequency twi ce a day, daily and two days are indicated for melon crop cultivated in san d soil by drip irrigation. The efficiency of water use for the melon crop i s higher when the irrigation frequencies are higher.