Ácido giberélico na germinação de sementes, vigor de plântulas e crescimento inicial de maracujazeiro

Abstract

This study aimed to evaluate the mode of action of gibberellin (4% gibberellic acid - GA3) on seed germination, seedling vigor and early growth of yellow passion fruit. For the standard germination test, seeds of passion fruit were pre-soaked for six hours in gibberellin in the following concentrations: 0,5; 1,0; 2,0 and 4,0 mL of product per liter of solution and water served as control, containing 20,0; 40,0; 80,0; 160,0 and 0,0 mg GA3 L-1 solution, respectively. It was evaluated on germination paper, the percentage of germination of normal seedlings in the first count, abnormal seedlings, dead seeds, firm seeds, root, stem and number of seedlings and sand, the index of germination speed (IVE). To evaluate the action of the product, by foliar sprays, the initial growth, the plant growth regulator was tested in two groups of plants: on seeds pre-soaked for six hours (solutions containing 20,0; 40,0; 80,0; 160,0 and 0,0 mg GA3 L-1 solution) and in plants grown from seeds without pre-soaking. Initially, seeds were sown in polyethylene bags with a capacity of 2 kg of washed sand. At 40 DAS the plant growth regulator was sprayed on the plants used for seven consecutive days and at 70 DAS was recorded: length of root, stem and total leaf number, dry mass of roots, leaves, shoots and total plants. At all stages, a completely randomized design with five treatments and four replications. It is concluded that gibberellic acid has positive effects on seed germination, seedling vigor and early growth of yellow passion fruit.