Flowering, flower predation and fruit set of <I>Ipomoea pes-caprae</I> and <I>I. imperati</I> (Convolvulaceae) at Joaquina Beach, SC

Abstract

The present study was made at the sand dunes of Joaquina Beach, Florianópolis, SC, Brazil. The flowering period and the fruiting period for Ipomoea pes-caprae and Ipomoea imperati, the fruit set percentage and the rate of predation in buds and flowers of these species were verified. The flowering peak of I. pes-eaprae occurred in January and February, while the fruiting peak occurred in March and April. The flowering peak of I. imperati was observed from November to April, while the fruiting peak was observed from December to June. The peaks of production of flowers and fruits for both species occurred during the months of high temperature and precipitation. In I. pes-caprae, the buds of the three size classes presented a fruit set percentage above 50% in the summer of 1990/1991, and above 80% in the summer of 1991/1992. In I. imperati, only large buds had a fruit set percentage above 50% in the summer of 1990/1991, while in the summer of 1991/1992 the buds of the three size classes exhibited a production of fruits above 60%. The highest percentage of fruit set in I. imperati was observed in large buds in both years. Predation was not observed in buds of I. pes-caprae for the majority of the inspections. In I. imperati, the rate of predation in buds varied and was relatively low reaching, in general, monthly mean values around 10% at the most. Small buds constituted the most predated in this species. The percentage of predation in corollas and/or reproductive structures of the flowers of I. pes-caprae and of I. imperati was low, generally bellow 15%.