ABSTRACT
Production of onion seedlings at the region of Alto Vale do Itajaí, Santa Catarina State (SC), Brazil, occurs predominantly in seedbeds, where the plants are exposed to biotic and abiotic factors that directly influence the leaf health and the yield. Thus, the aim of this study was to evaluate the influence of covering seedbeds with low tunnel system on the yield and intensity of leaf diseases. The experiments were carried out in 2012 and 2013 at “Instituto Federal Catarinense”, Rio do Sul, SC. The treatments were with and without low tunnel system. Experimental design was in randomized blocks with four replicates and ten plants evaluated in each replicate. Data were subjected to analysis of variance by the F test and if significant compared according to Tukey’s test 5%. The fresh weight of the aerial part with the tunnel was superior to the conventional system by 127.38% and 125.40% in 2012 and 2013, respectively. In 2012, there was a difference of 42.88% in the area under the disease progress curve (AUDPC) for leaf blight and in 2013 there was a difference of 87.27% and 85% in the AUDPC and final severity, respectively, for downy mildew. The seedlings grown in seedbeds with low tunnel system had superior yield and leaf health, compared to those obtained in the conventional production system.
Keywords
Allium cepa; plastic cover; yield; leaf sanity