Tratamento de sementes com fungicidas e inseticidas como redutores dos efeitos do estresse hídrico em plantas de soja

the objective of this research was evaluate four seed treatments: water (t1), carbendazim + thiram (t2), fipronil + thiophanate methyl + pyraclostrobin (t3) and abamectin + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (t4) on growth parameters of soybean plants with or without low water availability. the experiments were conducted under field conditions and greenhouse. in greenhouse, in treatments without low water availability, it was made four irrigations by day and in treatments with low water availability, it was made one irrigation each three days. in this trial, it was evaluated the plant height, root length, root volume, dry shoot weight, dry root weight and foliar area. in the field trial, low water availability was established by construction of low tunnels of polyethylene which prevented the water supply by irrigation and rain. in the field, it was also evaluated the plant height, the relative chlorophyll content, emergence, lesser cornstalk borer attack and grain yield. in the both environment, the plants were kept on stress until 28th days after emergence. in greenhouse, all the parameters were influenced by seed treatments with or without low water availability. in field, the treatment with fipronil + thiophanate methyl + pyraclostrobin (t3) and abamectin + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (t4) promoted higher plant height and relative chlorophyll content in both hydric schemes, higher emergence and grain yield in plants without and with lower water availability, respectively. it was concluded that seed treatment with these products promote benefit changes in plant, increasing its tolerance to hydric stress, with positive effect on soybean grain yield.