Produto baseado em mananoligossacarídeo na indução de tolerância ao déficit hídrico e desenvolvimento vegetativo da soja

Abstract

The soybean culture holds great significance in Brazilian agriculture, with Brazil being the world's largest soybean producer. In this context, biofertilizers produced through microbial fermentation have emerged as a source containing organic active principles that promote plant development and induce natural defense mechanisms. The objective of this study was to evaluate a product based on mannanoligosaccharide (PBM) concerning its effects on soybean growth and tolerance to water deficit. The experiment was conducted in a greenhouse using soybean plants, with the following treatments: T1 - Control, T2 - Salicylic Acid, T3 - Mineral Solution, T4 - PBM (0.5 L/ha), and T5 - PBM (4.0 L/ha), in a 2x4 factorial design (50% and 100% evapotranspiration) over a 77-day cultivation period. The treatments were applied directly to the soil at the time of soybean sowing. Biometric and photosynthetic evaluations were performed during soybean cultivation, and soil microbial activity was also assessed. In soybean cultivation without water deficit, PBM provided benefits such as increased aboveground growth, nodulation, photosynthesis, and nutrient accumulation. However, direct application of the product to the soil resulted in reduced root growth. Under water deficit conditions, the use of PBM did not mitigate the effects of stress on the plants. PBM applied to the soil has the potential to induce biochemical changes in the plant, with the lower dose of the product showing better performance in this study.