Caracterização morfofisiológica de sementes e plântulas de soja e milho em resposta diferencial à conjugação TSI e glifosato

Abstract

The present work aimed to carry out the morphophysiological characterization of soybean and corn seeds and seedlings in a differential response to the TSI and glyphosate conjugation, during the initial physiological performance. The soybean cultivar used was P98C81 and maize the hybrid P3898, both in their conventional versions. The experimental design adopted was completely randomized, in a factorial scheme (treated or untreated seed x 1 cultivar x 7 concentrations x 6 repetitions). The treated seeds were submitted to the treatment composed by Chloranthranilprone (Dermacor®), Clothianidin (Poncho®), Fludioxonil + Metalaxil-M (Maxim®), Carbendazim + Tiram (Derosal®), Pyrimiphos-methyl (Actellic®) and Deltamethrin (K -Obiol®). The concentrations of potassium salt (Check Mate®) were: 620.0 g L-1 or 62.0% w / v, as follows: Solution 1 - 0 mL of product to 1,000 mL of water; Solution 2 - 1.56 mL of product to 998.44 mL of water; Solution 3 - 3.12mL of product to 996.88 mL of water; Solution 4 - 6.25 mL of product to 993.75 ml of water; Solution 5 - 12.5 mL of product to 987.5 mL of water; Solution 6 - 25 mL of product to 975 mL of water; Solution 7 - 35 mL of product to 965mL of water. The solutions were used to moisten the substrate paper used for sowing. Germination, shoot length and primary root were evaluated and the qualitative characterization of the seedlings was performed. Under normal germination conditions, treated soybean seeds obtained a better result than untreated ones. There was a reduction on seedling roots for both cultures under exposure to increased glyphosate concentration. The main symptoms of abnormality observed in seedlings in glyphosate solution were shortening and stiffening of the primary root, cracks in the hypocotyl and yellowing of the cotyledons for soybeans and shortening and stiffening of the primary root, underdeveloped aerial part and yellowish or hyaline plumule for corn.