The effect of thermophilic compost on onion diseases and seedling quality used as basic fertiliser or bed cover was evaluated. The research was carried out in 1993 and 1994 in Ituporanga, Santa Catarina State, Brazil. Three experiments were conducted in randomised blocks with six replicates. The treatments were thermophilic compost, mineral fertilizer and organic-mineral fertilisers. In another experiment, the compost and the mineral fertiliser were combined with six plant densities in a factorial design experiment. For the seed bed coverage, new and one-year-old Pinus sawdust, soil, and thermophilic compost were evaluated using a randomised block design with four replicates. Thermophilic compost showed higher emergence and survival of onion transplants than organic-mineral and mineral fertiliser. The thermophilic compost increased the survival of onion transplants (101.4 pl/m²) and reduced Botrytis squamosa intensity (51.7%) when compared with the mineral fertiliser (87.7 pl/m² and 56.8%) regardless of plant density. Onion seedlings grown on seedbeds covered with compost presented higher emergence (146.1 pl/m²) and survival of seedlings (134.8 pl/m²) than those grown using only soil as coverage (90.2 and 77.5 pl/m², respectively). The occurrence of damping-off did not differ between treatments with fertilisers alone or treatments in which coverage was used in the seedbed.
Allium cepa; Botrytis squamosa; damping-off; organic fertiliser; transplants
