This present study aimed to evaluate the occurrence of female sterility and carpelloidy on hermaphrodite papaya cv. Baixinho de Santa Amalia growing under organic management in different types of environment protection and conducted with or without bifurcation of the trunk during the course of the four seasons. Three types of structures for crop protection were built side-by-side as follows: (i) greenhouse (plastic covering), (ii) shadowed greenhouse ('sombrite' net - 30% over the plastic sheet), and (iii) screenhouse ('sombrite' net - 30% exclusively), in an area of natural environment, for papaya (cv. Baixinho de Santa Amália) cultivation through organic farming system. Half of the plants in all treatments were submitted, right after sex determination, to apical incision for trunk bifurcation. For purposes of analysis of variance four blocks were considered by growth environment, each block having three replicates on how to conduct plant (with and without trunk bifurcation). For statistical analysis, it was proceeded the "jointly experiment analysis" method, in this case, the environments that were planted the plants. In papaya plant with a bifurcated trunk there was a decrease in the number of carpelloid fruits and increased number of female sterile flowers. However, this fact did not affect the production of normal fruits. During spring time, and especially in the greenhouse, the largest number of carpelloid fruits per plant was correlated at higher temperatures range, thermal amplitude and vegetative growth rate. The higher occurrence of staminate flowers was also correlated to high temperatures, low light and low vegetative vigor. Nevertheless, these same conditions favored the occurrence of perfect hermaphrodite fruits, thus contributing positively to papaya yield.
Carica papaya; organic farming; protected cropping; carpelloid fruit; female sterility
