Viability of onion seedling production on polyestyrene trays in three cultivars

The present trial was realized in Ponta Grossa (PR) and aimed to evaluate the viability of onion seedling production in polyestyrene trays, compared to conventional system on seedbed, using three cultivars The experimental design used was a randomized block with three replications. The treatments were arranged in a factorial scheme 30, being three seedlings type (from trays with 200 and 288 cells and from seedbed), and three cultivars (Mercedes, Bola Precoce and Crioula). Seedlings production on trays were realized under protected cultivation and seedlings from seedbeds produced in the field. Seeds were sowed in May, 15(th). At 57 days the seedlings were evaluated and then transplanted in plots with four rows and plants arranged in 0,40x0,08m, with 312.500 plants.ha(-1). The harvest was realized according to the plant maturation stage. Bulbs were dried and then yield were evaluated. The production cost and seedlings viability were calculated. It was observed the seedlings from trays were superior when compared to seedlings from seedbed, mainly those from 200 cells. This higher seedling quality reflected on later performance obtaining the highest yield from trays of 200 cells. It was intermediary with 288 trays and lower from seedbed seedling. It was observed low seedling useful from seedbed during the selection process (50%). In the case of hybrid the cost of seedling production in seedbed was high, almost comparable to seedling production of open pollinated cultivars on trays of 288 cells. The best cultivars were Crioula and Mercedes. Seedlings production on trays mainly on 200 cells showed viability and represents an important alternative to increase onion yield in a competitive market.