Sistema reprodutivo do cupuaçuzeiro (theobroma grandiflorum) - botão floral.

Abstract

The cupuaçu tree (Theobroma grandiflorum Schum) is a plant of the Sterculiaceae family, native to the Amazon, whose main product of commercial interest is the pulp of its fruit of pleasant taste and smell. Despite the demand, most of the production is still extractive, and the species lacks basic knowledge that can contribute to its transformation into a cultivated plant, especially those related to the studies that were proposed in the project "Reproductive system of Amazonian vegetal species", which aims to provide information on various aspects of the reproductive system of the species studied, with a view to using this information in programs of genetic improvement and rational production. The data were collected in the Experimental Field of the Center for Agroforestry Research in the Oriental Amazon - CPATU/EMBRAPA, in a plantation formed by grafted plants. Initially they were labeled at the BF2-3 stage (Closed bud between two and three millimeters in diameter) and observed: 104 and 65 buds daily, until the FA stage (Open Flower), distributed in twelve plants producing fruits with seeds (PCS) and six producing fruit without seeds (PSS), respectively. Then, another trial was installed using twelve plants, six PCS and six PSS, where all buds and flowers were collected and counted, twice a week, in the soil under the plants. In the first trial it was found that in the PCS, 54 buds (51.92%) reached the FA stage, taking an average of 25 days, with a range of variation of 19 to 34 days. On the day before opening, the buds presented, on average, 13.42 mm in length and 13.06 mm in diameter, ranging from 11.0 to 15.06 and from 10.4 to 16.2 mm, respectively; in the PSS only 20 buds (30.77%) completed the development, with the average opening, the buds presented, on average 14.85 mm in length and 12.96 mm in diameter, ranging from 11.0 to 15.06 and from 10.40 to 16.2, respectively. In the second it was observed that of the 21,578 buds issued at the BF2-3mm stage 5,004 buds (23.18%) fell at the various stages for the PCS. For the PSS, out of a total of 13,374 buds, 4,579 (34.24%) fell.