SOUSA, Francisco Braz de.
Resumo:
The triploid watermelon has been gaining more and more space in the fruit sales market
in Brazil. One of the main problems faced by producers is the low percentage of seed
germination, which directly influences their productivity. Therefore, this present work
aims to evaluate the effect of gibberellic acid (GA3) concentration and water imbibition
time on the emergence and growth of triploid watermelon seedlings. The experiments
were carried out at the Laboratory of Plant Physiology and Vegetation House of the
Academic Unit of Agrarian Sciences of the Center for Agro-Food Science and
Technology at the Federal University of Campina Grande, campus of Pombal - PB,
from 07/28 to 09/15/ 2021, using the watermelon hybrid 'Lola'. In experiment 1,
treatments consisted of four concentrations of gibberellic acid (0, 200, 400, 800 mg L1). In experiment 2, the treatments consisted of four times of imbibition in water (0, 6,
12, 24 h). The experimental design used was completely randomized, with three
replications, with 25 seeds each. After applying the treatments, the seeds were sown in
polypropylene trays (styrofoam) with 128 cells containing commercial substrate
Tropstrato HT Hortaliças® and placed in a greenhouse covered with plastic and 30%
shade. The characteristics evaluated were: Percentage of germination at five and twelve
days, emergence speed index, plant height, number of leaves, root length, dry mass of
leaf, stem, root and total. The collected data were submitted to analysis of variance and
regression. There was an increase in plant height and a reduction in the germination of
watermelon seeds with the increase in the concentration of gibberellic acid. The other
characteristics evaluated were not influenced by the application of gibberellin. For the
soaking time, there was an increase of 23.3% in the number of plants emerged in 24
hours. According to the behavior of the results obtained in this research, we can
conclude that gibberellin does not improve germination in triploid seeds and that the
positive response to imbibition in water is related to physical limitations in the
tegument, not yet possible to be clarified in this work.
