Controle de patógenos associados às sementes de canola, cártamo, colza e crambe

Abstract

Plant disease control through seed treatment often results in higher seedling stand, vigorous and disease free plants. It is a relatively inexpensive and highly efficient practice for plant disease management. The objective of this study was to evaluate the effectiveness of fungicides to control fungi and their effects on germination and seedling emergence of crambe, safflower, canola and rapeseed. The experiments were conducted at the Universidade Federal da Grande Dourados. The treatments were: fludioxonil (1 mL kg-1), carbendazin + thiram 4.3 mL kg-1 (30 and 70%), difenoconazole (0.34 mL kg-1), carbendazin (1.55 mL kg-1 ), iprodione (1 mL kg-1), thiram (3.15 g kg-1), carboxin + thiram 7.5 mL kg-1 (50 and 50%), thiabendazole (3 mL kg-1) and pyraclostrobin + thiophanate – methyl + fipronil 2.85 mL kg-1 (5, 45 and 50%), and water as control treatment. The experimental design was completely randomized design with ten treatments and four replications for the evaluation of germination and emergence, and eight for seed pathology. We analyzed: field emergence, emergence rate index (EVI), germination, and seed pathology. The species of crambe and safflower showed a higher incidence of fungi than canola and rapeseed. Seeds treatment with pyraclostrobin + thiophanate - methyl + fipronil reduced fungi incidence in all species evaluated. In the germination test canola oil, phytotoxicity symptoms associated with pyraclostrobin + thiophanate - methyl + fipronil were observed as reduced germination, but with no affect on emergence. The fungicides thiram and pyraclostrobin + thiophanate - methyl + fipronil resulted in increase of 245.95% and 256.76% respectively in root length of crambe compared with control. The safflower seed treatment with iprodione showed the highest root length.