Formulações e tempo de contato de sementes com Trichoderma spp. no crescimento inicial da soja

Abstract

Soybean is one of the most cultivated crops in Brazil and it is constantly seeked further development and production of plants. For this, there are used chemicals products and formulated with microorganisms such as Trichoderma spp. in the seed treatment. Trichoderma spp. is a soil fungus known as biological control agent of pathogens of plants and plant growth stimulator. The objective of this study was to analyze the interference of the form of treatment and time of contact of seeds with Trichoderma spp. in the emergence and early growth of soybeans. Two experiments were conducted in greenhouse using three forms of treatment of seed: water restriction, formulated liquid and formulated powder with Trichoderma spp, with seven periods of contact: 0h, 4h, 8h, 12h, 24h, 48h and 72h. There were used 120 seeds of the soybean cultivar “Potencia” for contact time, totaling 840 seeds by treatment + control treatment. After each period the seeds were sown in gerbox and in pots containing sieved soil. The evaluations for the experiment in gerbox occurred seven days after sowing and in pots they occurred seven and thirty days after sowing. The variables evaluated were: seedling emergence, length of aerial part, root length, fresh weight and dry weight of shoot and root and nodule number in the pots. It was observed that there was interaction between the factors forms of treatment and contact time to seedling emergence, dry weight of root and dry weight and green of shoot. For the other variables, there was significance to the form of treatment and or the contact time. To the number of nodes, the time of contact of 12h was the most appropriate. Therefore, it can be concluded that there is interference of treatment of seed and the time of contact with the fungus for the early growth of soybean. The water restriction has the greatest stimulus in the emergence and in early growth. The contact time that stimulates the emergence and the early growth of plants is the time of 8h.