Flowering phenology and fl oral biology in pumpkin cultivars

Resumo

Phenological events, in particular, flowering phenology and aspects of floral biology help to understand the
relationship of plants with their pollinators. Thus, this study sought to estimate, under semi-arid conditions, the relationship
between different genotypes of pumpkin or winter squash (Cucurbita moschata Duch.) and the environment, under the aspects of
reproductive biology. Four cultivars were evaluated in three productive cycles, measuring the variables daily flower emergence,
stigma receptivity, anthesis time and the morphometry of pistil and staminate flowers. The production of male flowers was
higher than female flowers with a higher proportion in the third production cycle characterized by higher air temperature and
lower relative humidity. Among cultivars, ‘Jacarezinho’ and ‘Sergipe’ presented the highest and the lowest values of flower
production, respectively. Female flowers remain open longer than male flowers and stigmas remain receptive until the flowers
close. Considering the morphometric data, there is positive association between the petal length and the corolla diameter, and
between access to the nectar and the anther size, with a difference between cultivars and cultivation conditions.