Efeito da densidade de mudas por célula e do volume da célula na produção de mudas e cultivo da rúcula

Abstract

The experiment was realized in Ponta Grossa (PR) aiming at avaluating seedlings density/cells using different trays and its effects on seedlings production and yield of rocket press. The experimental design was a randomised blocks with four replications; the treatments followed a factorial arrangement 4 x 2, being 1, 2 , 3 and 4 seedlings/cell on trays with 200 and 288 cells. Seeds were sowed on 28/03/2003, with the cultivar Cultivada on trays with commercial substrate Plantmax under protected cultivation. Before seedlings transplanting it was avaluated the characteristics of leaves number, lenght of upper part and root, fresh and dry weight of up ground material and root. The seedlings transplanting was carried out through with seventeen days in plots containing 40 plants in 0,20 x 0,10 m arrangement. At harvesting, 20 days of the seedlings transplanting, it was avaluated the following characteristics: lenght of upper part, leaves number, fresh and dry weight of up ground material. On the seedlings stage it was observed a significative effect of the interaction. The cell size was an important factor on seedlings production and it depended also on seedlings densities/cell. The best seedlings quality was obtained using trays with 200 cells, compared to 288 cells. Increasing the seedlings density/cell it was observed higher effect of seedlings competition, mainly on trays of 288 cells on the characteristics of leaves number, fresh weight of up ground material and lenght of upper part and root. However these differences were diluted during plants development on the field, being at the harvesting only the characteristic of leaves number still superior on trays of 200 cells (volume of 16 cm3) compared to 288 cells (12 cm3). On the other hand the seedlings density/cell promoted yield response on rocket press. It was observed linear response on yield. It was observed decreasing on lenght of upper part, leaves number, fresh and dry weight of up ground material, in response of competition pressure among plants promoted by density increasing. However it was observed linear increment on yield/area with the increasing of the seedlings/density. The increment on fresh weight was significative considering yield average of 1,4 kg m-2 on density of single seedling and 6,4 kg m-2 when it was used four seedlings/cell. It was observed that when density was increased, higher was the yield on fresh weight to both trays. Considering the commercialization of rocket press mainly on bunch, it seems more interesting a higher density with four seedlings, on trays with 200 or 288 cells.