Effect of irrigation levels in the yield of papaya (group Formosa) in the Plateau of Apodi, CE..

Abstract

The influence of irrigation levels on the yield and other production indicators of papaya (group Formosa, hybrid “Know you Seed”) was evaluated in field trials conducted in the Plateau of Apodi, Limoeiro do Norte county (Ceará - Brazil). The experimental followed a randomized blocks design with five irrigation levels based in the proportion of the readings of a Class “A” evaporation pan  - ECA (20% ECA; 40% ECA; 60% ECA; 80% ECA and 100% ECA), and four replications. The plants were irrigated by a microsprinkler system, with a lateral line placed between two lines of plants, and an emitter for each four plants. The following production indicators were evaluated: yield per plant, number of fruit per plant, mean weight of fruit, and the productivity of the field. The total irrigation depth of 1769.5 mm; 1385.9 mm; 1039.5 mm; 693.0 mm and 346.0 were applied, respectively for the 100; 80; 60; 40 and 20% of ECA treatments. All the indicators evaluated tended to increase with the applied depth.  The maximum mean yield per plant, number of fruits per plant, mean weight of fruits and productivity of the field were 98.37 kg.plant-1, 5.99 fruits.plant-1, 0.89 kg.fruit-1 and 38.98 t.ha-1, respectively, obtained in the treatment 100% of ECA, corresponding to an irrigation depth of 1769.5 mm.