Effects of foliar gibberellic acid application on onion seed yield
HORTICULTURE | Gaviola, J.C. - Lipinski, V. - Della Gaspera, P.G.
Tags: bolting, seed quality, seed to seed method, Allium cepa, floral induction
Onion (Allium cepaL.) is one of the main horticultural species in Argentina. The supply of seeds of this species is mainly from national production. Gibberellic acid (AG3) in onion is effective to induce flower buds when applied before or during the period of low temperatures.Throughout three seasons in La Consulta, Mendoza, Argentina, AG3 was tested to determine its effects on the seed production of onion cv Valcatorce INTA using the seed-to-seed method. The treatments were 0-200-400-600 mg.L-1 of AG3 in the first season and 0-300-600-900 mg.L-1 of AG3 in the other two; the plants were sprayed when they had between 5 and 7 leaves.The design was complete blocks with random plots and five replications. The number of umbels per plant, the seed yield per plant and unit area, and the seed quality, were determined. Gibberellic acid increased the number of umbels per plant.In the first two seasons, the highest seed yield per unit area was achieved with the use of the highest dose of AG3. However, in the third season, the best performance was obtained with 300 mg.L-1. The application of AG3 with the highest doses tested decreased the weight of a thousand seeds in two seasons without impairing germination.