EFFECT OF BIOPRODUCTS AND MICORRYZHAL INOCULATION ON SOYBEAN RUST IN A FIELD CONDITIONS

One of the greatest challenges to the near future is to produce food in greater quantity and quality, preventing environmental problems as soil and water contamination and the increase resistance of pests and diseases that affect yield. The main problem to increase crops production in Brazil is a soybean rust (SR), caused by the fungus Phakopsora pachyrhizi. The alternatives today is the use of agrochemicals but most of the pathogens shows resistance. The challenge today is find new products with low toxicity and high antifungal effect. One alternative is to use antimicrobial bioproducts to control SR. Arbuscular mycorrhizal fungi (AMF) is a symbiotic obligate which colonize plant root release P to plant and protect against disease by two ways. First one AMF increases plant nutrition supplying nutrients to plant as P, N and micronutrients and the second one AMF active plant response against pathogens. In those experiments, it was used a natural fungicide associated with AMF to control P. pachyrhizi. In this context, the objective of this work was to evaluate the effect of bioactive compounds produced by secondary metabolism of Pseudomonas aeruginosa LV strain, to control SR, and an inoculant AMF-based (Rhizophagus clarus), produced in vitro. The experiment was carried out at 2016/17 crop, at Londrina-PR. The design experiment was randomized block with seven treatments, and was evaluated the efficiency of the semi purified fraction F4A in two doses (1 and 10 μg mL-1) in association with commercial products (Unizeb Gold® or Sphere Max®). As agronomic treatment was used the fungicides Unizeb Gold® + Sphere Max®. All treatments were inoculated with R. clarus. At the end of the experiment was evaluated the mycorrhizal colonization, N and P contents and yield. The highest colonization was presented in plant treated with F4A 10 μg mL-1 plus Sphere Max®. P content of leaf was bigger in plant treated with Unizeb Gold® + Sphere Max®, followed by F4A 10 μg mL-1 + Sphere Max® and F4A 10 μg mL-1 + Unizeb Gold® respectively, while in N content, Unizeb Gold® + Sphere Max® was the highest value. Finally, the yield, F4A 1 μg mL-1 was bigger followed by F4A 1 μg mL-1 + Sphere Max®, F4A 10 μg mL-1 + Sphere Max® and Unizeb Gold® + Sphere Max®. The results showed F4A fraction is a very promisor compound to use in the control of SR and could help to protect soybean.