Desempenho de sementes de Vigna unguiculata (L.) Walp tratadas com fungicidas, inseticidas e micronutrientes sob diferentes condições de armazenamento

Abstract

Cowpea is a leguminous very cultivated in North and Northeast in Brazil. It is a crop from Africa, but it has good adaptability in these areas. It is important protein source for poor people of these regions, besides generating employment and income. Seed treatment is important to control and prevent possible pests and diseases attacks that could damage physiological seed quality, reduce plant stand and cause economic damage. It is also possible to apply nutrients via seeds; in this case, nutrients will be readily available to plants shortly after germination. Therefore, the objective of this study was to evaluate the performance of cowpea seeds treated with fungicides, insecticides and micronutrients in different storage conditions. The experiment was conducted at Seed Analysis Laboratory of the Federal University of Paraíba, and the seeds were treated as follows: 1-control (no treated), 2-micronutrient Comol 118 (composed of 1% cobalt and molybdenum 8%), 3-thiamethoxan insecticide (Cruiser 350FS® - 300mL per 100kg of seed-1), 4-Insecticide and fungicide: fipronil and pyraclostrobin + thiophanate methyl (Standak® top-200mL per 100kg of seed-1), 5-Imidacloprid + thiodicarb (Cropstar ® - 300mL- per 100kg of seeds-1). After treated the seeds were stored at natural environment and preservation chamber. The assessment of physiological seed quality was done at 0, 45, 90, 135 and 180 days of storage and the following tests were performed: seed germination and seed vigor (first count of germination, accelerated aging, seedling length, seedling emergence and emergence speed index). It was concluded that the treatments with (imidacloprid+thiodicarb) and (fipronil+pyraclostrobin+thiophanate-methyl) provide stimulating effect on seed performance; and seed treated with thiamethoxan are less negatively affected than seed not treated with this product; treatment with micronutrients show similar behavior to untreated seeds and seed storage at natural environment negatively affect seed quality as the period of storage is increased.