Control of Fusarium verticillioides in maize stored in silo bags with 1-octyn-3-ol

Abstract

Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium verticillioides, a pathogenic fungus that attacks maize grains both in the field and during storage, causing significant economic losses for the food industry. To control F. verticillioides in maize grains, synthetic chemical fungicides are used successfully, which are potentially dangerous for the environment and health. For this reason, society demands the development of biocontrol methods for pests, such as the use of natural compounds. The objective of this study was to evaluate the effects of alcohols on F. verticillioides in maize grains stored in silo bags. The compounds used in the bioassays were benzyl alcohol, 1-hexen-3-ol, 3-buten-1-ol, and 1-octyn-3-ol. The in vitro effect of the different alcohols was determined by evaluating the fungal growth on Petri dishes with Czapek-Dox agar. Subsequently, a filter paper with 1-octyn-3-ol (minimum inhibitory concentration (MIC), 1.5 MIC, or 2 MIC values) was incorporated in silo bags containing maize and a conidial suspension of F. verticillioides. After twenty-eight days of storage under natural environmental conditions, the quantification of ergosterol, colony forming units (CFU/g), and FB1 in maize grains were conducted. In vitro assays showed that the most active compounds were 1-octyn-3-ol, 1-hexen-3-ol, and benzyl alcohol, with MIC values of 0.14, 2.18, and 3.84 mM, respectively. The growth rate of F. verticillioidesdecreased with increasing concentration of the compounds. Assays conducted with maize grains stored in silo bags showed that the 2 MIC of 1-octyn-3-ol completely inhibited the development of F. verticillioides and the consequent production of FB1. Therefore, 1-octyn-3-ol could be a promising tool for the control of F. verticillioides in maize and the application of this compound inside the silo bag could prolong the storage time of the seeds within this system.