Reproductive phenology of Passiflora cincinnata Mast. in the semi-arid region of Bahia State, Brazil, based on herbarium data and IDW interpolation

ABSTRACT We investigated intensity and seasonality of the reproductive phenology of Passiflora cincinnata Mast. and estimated its flowering and fruiting periods by interpolation using Inverse Distance Weighting, for the first time in phenology, based on herbarium collections from Bahia State, Northeastern Brazil. Data from 249 exsiccates with flowers and/or fruits were analyzed to estimate the amplitude of flowering and fruiting and test the seasonality using the circular statistics. Passiflora cincinnata flowering and fruiting was greatest from October to May. The maps generated by interpolation showed greatest probability of flowering and fruiting between March and May in sites with mean annual rainfall rates between 500 and 1000 mm. Our results indicated seasonality of flowering and fruiting, with reduced intensities during the austral winter. The interpolation methodology can be used in a complementary or preliminary way, either to organize field visits and set up experiments, or to extrapolate field results for larger-scale views.