Nanotecnologia no controle in vitro de Colletotrichum truncatum e Colletotrichum plurivorum

Abstract

Anthracnose, caused by fungi of the genus Colletotrichum sp., is one of the main threats to cultivated plants worldwide. Crops of great economic value, such as soybeans, corn and cotton, when exposed to high pressure from the pathogen, can suffer serious productivity losses, forcing farmers to adopt rigorous control strategies. In this context, nanotechnology emerges as a promising ally in disease management, allowing greater persistence of applied products through controlled release, reducing losses due to factors such as pH and volatilization, in addition to enabling the use of lower concentrations of the active ingredient. The objective of this study was to evaluate the in vitro antifungal efficacy of nanoemulsified limonene on Colletotrichum truncatum and Colletotrichum plurivorum. The experiment was conducted in a completely randomized design, with five replicates and three treatments: White Nanoemulsion (NEBr), Nanoemulsion with Limonene (NELim) and Pure Limonene (LIMPu), tested at concentrations of 10, 20, 30, 40 and 50%, in addition to the absolute control (PDA). Mycelial growth (MC), area under the mycelial progress curve (AUCPM), percentage of mycelial growth inhibition (%PIC), percentage of spore production inhibition (%PIE) and percentage of spore germination inhibition (%PIG) were evaluated. The results demonstrated that LIMPu was the most effective treatment in inhibiting mycelial growth, presenting the lowest AUCPM values and the highest percentages of growth inhibition (%PIC) for both fungi tested. However, its action on sporulation and spore germination (%PIE and %PIG) was limited. On the other hand, NELim, although less efficient in controlling mycelial growth, stood out in controlling sporulation and spore germination. NEBr, in turn, showed low efficacy in both inhibiting mycelial growth and spore germination, especially at concentrations above 30%, and in some cases even stimulated fungal growth. Therefore, pure limonene proved to be more effective in controlling mycelial growth, while the nanoemulsion containing limonene showed promise in controlling sporulation and spore germination of the phytopathogens evaluated. Thus, the use of nanotechnology, such as nanoemulsions, can be an advance in the management of agricultural diseases, offering new, more effective and sustainable control alternatives.