Influence of trays type on seedlings production and bulb yield and quality in differents onion cultivars under no tillage system

Onion crop (Allium cepa L.) is one of the important vegetable on South, with 71,8% of the whole onion area in Brazil. From this total, Parana State shows only 8,6% having low yield of 10,7 t/ha. Its necessary advance on the usual technology and new techniques to become competitive. This experiment aimed to evaluate seedlings production on differents trays and its performance on plant development, bulb yield and quality under no tillage system. Seedlings production were carrried on protected cultivation, with a experimental design of randomized block and three replications; the treatments followed a factorial scheme 4 x 3, being four cultivars (Mercedes, Bola Precoce, Crioula and Montana) and three polystyrene trays (128, 200 and 288 cells). Seedlings obtained from trays of 128 cells were named M1, and those one obtained from 200 (M2) and 288 (M3). The substrate was Plantmax (R) and seeds were sowed in June, 16(th). At 54 days seedlings were avaluated on the characteristics of height of upper part and root, fresh and dry weight of up ground and root material. At the field trial, the seedlings were transplanted at 55 days using a experimental design with three replications and the following treatments: Mercedes M1; Mercedes M2; Mercedes M3; Bola Precoce M1; Bola Precoce M2; Bola Precoce M3; Crioula M1; Crioula M2; Crioula M3; Montana M1; Montana M2 and Montana M3. During plant development it was avaluated the lenght of upper part, leaves number and the neck diameter. The harvest was realized in differents data in according of plants maturation. Bulb yield were avaluated and graded by diameter into classes. The different trays (128, 200 and 288 cells) promoted the development of seedlings with different size. The best seedling quality was obtained from trays of 128 cells to all cultivars mainly on the characteristics of height of upper part, fresh weight of upper ground material and root lenght. The seedlings promoted expressive plant development, high yield (79,23 t. 8000 m(-2)) and bulb quality, having the cultivars Mercedes and Bola Precoce (with seedlings M1 and M2) and Crioula and Montana (with seedlings M1, M2 and M3), percentage higher than 75% of the yield in bulbs graded into classes 3C and 4.