Tratamento de sementes de cebola com bioestimulante comercial a base de algas

Abstract

The onion, Allium cepa L., is a vegetable originally from Asia and belongs to the family Amaryllidaceae and subfamily Allioineae. In Brazil, the onion is mainly produced on small rural properties and represents an important source of income for producers, however, sometimes the price offered to producers is below the average cost of vegetable production. In this sense, the seeds treatments with the use of biostimulants appears as an excellent alternative to improve germination and the initial development of the seedlings. The objective of this work is to evaluate the effects of the seeds treatments with commercial biostimulant based on seaweed Ascophyllum nodosum on the germination and seedling growth of different onion cultivars. The experiment was carried out in the Seeds and Grains Laboratory of the Universidade Federal da Fronteira Sul, Chapecó, in a completely randomized design, in a 2 x 4 factorial scheme (cultivars x doses) with 5 replications. Were used onion seeds of Baia Periforme and Crioula cultivars and commercial biostimulant based on seaweed Ascophyllum nodosum. The bioestimulante doses used in seed treatment were 0, 12, 24 and 48 ml.kg⁻¹ of seeds. Were elanuated the percentage of germination at 6 days after sowing and 12 days after sowing, and percentage of abnormal seedlings, length of seedlings (shoot and roots) and seedling mass (fresh and dry) 12 days after sowing. The results obtained in the tests were subjected to analysis of variance, regression analysis and the Tukey test at 5% probability. In general, the cultivar Baia Periforme showed higher averages than the Crioula cultivar. For the cultivar Baia Periforme, an increase in germination was observed at the first count at a dosage of 24 ml.kg⁻¹ of seeds, however in the other variables analyzed, treatments with the addition of biostimulant did not differ from the control treatment. For the Crioula cultivar, an increase in the shoot length was observed with a dosage of 12 ml.kg⁻¹ of seeds, but reductions in germination potential, increases in the germination of abnormal seedlings, significant reductions in root development and accumulation of fresh and dry mass were also observed depending on the addition of biostimulant doses.