ABSTRACT

Weed control is a critical factor to ensure productivity and quality for food production. Chemical control is the main method used worldwide, but the demand for healthier food and the farmers’ health and environment concerns have led to an increase in the search for alternative control methods. In this way, the use of biomolecules produced by microorganisms that present phytotoxic activity against weeds, such as exopolysaccharides, is attracting attention. For this purpose, this work compared two techniques (solid-state and submerged fermentation) for bioherbicide production by Diaporthe schini. Physicochemical characterization of both fermented broth and evaluation of bioherbicidal effect in post-emergence of Amaranthus viridis, Bidens pilosa, Echinocloa crusgalli, and Lollium multiflorum were performed. Fungal broth obtained by submerged fermentation presented better physicochemical characteristics in terms of viscosity, density, and surface tension. Overall, it was more effective than the broth obtained by solid-state fermentation for weed control because it presented an average inhibition of 40% of weed growth and 45% lower surface tension if compared to the control test. Also, reductions of 1.4–4.2 times of root dry mass, 2.9–5.8 times of shoot dry mass and 1.2–3.9 times of weeds heights, if compared to the control test, were achieved.

摘要

杂草控制是确保粮食生产的生产力和质量的关键因素。化学控制是世界范围内使用的主要方法，但对更健康食品的需求以及农民对健康和环境的关注导致对替代控制方法的寻找增加。通过这种方式，由微生物产生的对杂草具有植物毒性活性的生物分子（例如胞外多糖）的使用受到关注。为此，这项工作比较了 Diaporthe schini 生产生物除草剂的两种技术（固态发酵和深层发酵）。发酵液的理化特性及其对绿苋、白刺苋芽后生物除草效果的评价，进行了稗草和黑麦草。通过深层发酵获得的真菌肉汤在粘度、密度和表面张力方面表现出更好的物理化学特性。总体而言，它比通过固态发酵获得的肉汤控制杂草更有效，因为与对照试验相比，它平均抑制 40% 的杂草生长和降低 45% 的表面张力。此外，与对照试验相比，根干质量降低了 1.4-4.2 倍，枝条干质量降低了 2.9-5.8 倍，杂草高度降低了 1.2-3.9 倍。