Anthesis of female flowers of 'Tetsukabuto' squash occurs within three to four weeks. A deficient pollination during this short flowering period may reduce the yield. The sodium salt of alfa-naphthaleneacetic acid (Na-NAA) can be used to improve fruit set when pollination is deficient. This work was conducted to investigate the effects of different concentrations of Na-NAA, sprayed in open female flowers on fruit set and fruit growth of 'Tetsukabuto' squash. The experiment was carried out in 1992-93, in South Brazil, in a randomized block design with three replicates. The plots had a proportion of five plants of 'Tetsukabuto' to one plant of pollinator (Cucurbita maxima), sowed on a spacing of 3 x 1 m. The treatments consisted of 150, 300, 450, 600, and 750 mg·L-1 of Na-NAA, plus the control (with natural pollination). Plants treated with Na-NAA had the flowers covered with paper bags to prevent pollination. The treatments were assessed for fruit set and fruit size (weight and diameter) and pulp yield (fresh weight/fruit, thickness, and total solids) at harvest. Only the highest Na-NAA concentration (750 mg·L-1) reduced fruit set. Na-NAA did not affect fruits growth and pulp yield.
Cucurbita maxima x C. moschata; flowering; auxin; fruit growth
