Expressão sexual do mamoeiro sob diferentes lâminas de irrigação na Região Norte Fluminense

Imperfect flowers occurrence in hermaphrodite plants of papaya tree is related to genetic causes, which are affected by environmental factors. High humidity conditions as well as high concentration of water and nitrogen in the soil tend to change the sex of the hermaphrodite flowers producing deformed fruits. The intent of this work was studying the production behavior of flowers of hermaphrodite types of the papaya tree 'Improved Sunrise Solo 72/12' affected by the application of different depth of water in the North Region of Rio de Janeiro, Brazil. The experiment was carried out under randomized block design with seven treatments (depth irrigation) three repetitions and five useful plants in each experimental plot. The water was applied by microsprinkler irrigation system. The treatments applied were seven percentages of the reference evapotranspiration (T1 = 0; T2 = 40; T3 = 80; T4 = 120; T5 = 160; T6 = 200 and T7 = 240% of ETo). After the flower emergence the numbers of sterile flowers, carpelloid and pentandric fruits were evaluated monthly. The sterile flowers occurrence was responsible for the largest losses in the production and it was larger in the summer and become worse with the water deficit. The adoption of irrigation amount of 120% of ETo, minimized the losses caused by production of imperfect flowers.