Fall armyworm is one of the main insect pests in Brazil. Thus, the present work aimed to evaluate the seed treatment effect on the control of Spodoptera frugiperda in initial infestations of soybean crops. The experimental design was completely randomized with four replicates of six insecticide treatments applied through seed treatment: imidacloprid plus thiodicarb at the dose of 52.5 plus 105 g a.i. (active ingredient) 100 kg-1 of seed (Cropstar® 0.350 L 100 kg-1 of seed); thiamethoxam at 105 g a.i. 100 kg-1 of seed (Cruiser 350 FS® 0.3 L 100 kg-1 of seed); chlorantraniliprole at 62.5 g a.i. 100 kg-1 of seed (Dermacor® 0.1 L 100 kg-1 of seed); cyantraniliprole at 120 g a.i. 100 kg-1 of seed (Fortenza 600 FS® 0.2 L 100 kg-1 of seed); fipronil plus pyraclostrobin and thiophanate-methyl 50 + 5 + 45 g a.i. 100 kg-1 of seed (Standak Top® 0.2 L 100 kg-1 of seed), and a control treatment. The experiment was carried out in a greenhouse. Diamide insecticides (chlorantraniliprole and cyantraniliprole) presented the best results among all treatments, with lower consumption of the treated leaves by the caterpillars and greater control efficacy of this insect. We verified that seed treatment is a viable alternative for controlling S. frugiperda at the beginning of crop development, when the caterpillar presents the behavior of cutting the seedlings and/or the consumption of leaf area, causing a reduction in the plant population and a consequent yield loss.

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Seed treatment is a process that helps to control insects and soil-borne pathogens, besides allowing a given crop to reach its maximum production potential and protect its seedlings. This study aimed to evaluate the physiological performance of seeds and the initial development of soybean, as a function of seed treatment. The study was based on a completely randomized design, with five treatments [imidacloprid + thiodicarb (75 + 225 g a.i. 100 kg-1 of seeds); chlorantraniliprole (62.5 g a.i. 100 kg-1 of seeds); cyantraniliprole (72 g a.i. 100 kg-1 of seeds), fipronil + thiophanate-methyl + pyraclostrobin (5 + 45 + 50 g a.i. 100 kg-1 of seeds); and control (seeds without treatment)]. Initially, the physiological quality of the seeds was evaluated by determining the first germination count, final germination and accelerated aging, with four replications. After that, the effect of the seed treatment on the soybean plant development was evaluated by analyzing the leaf area, number of leaves, shoot height, root and shoot dry mass and fresh mass of root nodules, with ten replications. The seed treatment with fipronil + pyraclostrobin + thiophanate-methyl allows an increased germination when the seeds are subjected to the accelerated aging test, besides an increment in the shoot height and leaf area of the plants.

Chemical seed treatment is a practice that assists in control of pests and pathogens and allows crops to achieve their maximum yield potential. However, the storage period of seeds treated with insecticides and fungicides can affect seed physiological potential. The aim of this study was to evaluate the physiological quality of soybean seeds treated with different fungicides and insecticides after four different storage periods. The experimental design was completely randomized and the treatments were distributed in a 10 × 4 factorial arrangement in which the soybean seeds of the cultivar BMX Potência RR were treated with the following phytosanitary products: fipronil + pyraclostrobin + thiophanate-methyl, thiophanate-methyl, carbendazim, carboxin + thiram, imidacloprid + thiodicarb, chlorantraniliprole, thiamethoxam, cyantraniliprole, fipronil, and a control (seeds without chemical treatment), in four replications. The seeds were evaluated at 0, 30, 60, and 90 days after the chemical treatment. The following tests were performed: germination, first count of germination, accelerated aging, seedling emergence in sand, seedling emergence speed, and seedling dry matter. The treatment with the carboxin + thiram fungicide mixture provided for adequate physiological quality of the seeds throughout storage. The insecticide thiamethoxam has a negative effect on the physiological quality of soybean seeds that are stored after treatment with it.

Adjuvants mayimprove control efficiency of volunteer RR ® corn with ACCase inhibiting herbicides. Thus, the aim of this study was to evaluate the effects of adjuvant addition to the herbicides clethodim and quizalofop, on surface tension, spray deposition and efficiency of volunteer RR ® corn control. The surface tension of clethodim (96 g a.i. ha -1 ) and quizalofop (60 g a.i. ha -1 ) herbicides with and without a mineral oil, a vegetable oil and an organosilicon adjuvant was evaluated at concentrations of 0.01; 0.05; 0.1; 0.5; 1.0 and 2.0% v v -1 . To evaluate deposition and visual control efficiency, the same herbicides associated or not with the mineral oil (0.5% v v -1 ), the vegetable oil (0.5% v v -1 ) and the organosilicon adjuvant (0, 05% v v -1 ) were used. For this, volunteer RR ® corn plants were grown in a greenhouse until stage V2-V3. The adjuvants reduced the surface tension of the herbicides clethodim and quizalofop, organosilicon was the most efficient.Adjuvants does not alter spray deposition of herbicides on corn plants. Mineral oil increases potential control of clethodim herbicide and anticipates control with quizalofop herbicide.