Efficacy of preharvest application of biocontrol agents against gray mold in grapevine

Abstract

The use of biocontrol agents (BCAs) represents a promising alternative to conventional methods for the management of gray mold in vineyards during the berry ripening stage. The main advantages of BCAs are the short preharvest interval and lack of chemical fungicide residues in wine. In this study, eight commercial BCAs (based on different Bacillus or Trichoderma species and strains, Aureobasidium pullulans, Metschnikowia fructicola, and Pythium oligandrum) and a reference fungicide (boscalid) were applied to a vineyard during berry ripening over three seasons to evaluate the dynamics over time in terms of their relative efficacies in gray mold control. At 1–13 days after application of BCAs to the berry surfaces in field conditions, the berries were collected and artificially inoculated with conidia of Botrytis cinerea under controlled laboratory conditions, and gray mold severity was observed after 7 days of incubation. Significant differences were observed in gray mold severity among years, according to the number of days the BCAs grew on the berry surface before B. cinerea inoculation, and the season by day interaction (altogether accounting for >80% of the experimental variance). The variability in BCA efficacy was closely related to the environmental conditions at the time of application and in the following days. Overall, the BCA efficacy increased with the degree days accumulated between BCA application in the vineyard and B. cinerea inoculation in the dry (no rain) periods (r = 0.914, P = 0.001). Rainfall and the associated drop in temperature caused a relevant reduction of BCA efficacy. These results demonstrate that BCAs are an effective alternative to conventional chemicals for the preharvest control of gray mold in vineyards. However, environmental conditions can considerably affect the BCA efficacy.

Challenges and Opportunities Arising from Host–Botrytis cinerea Interactions to Outline Novel and Sustainable Control Strategies: The Key Role of RNA Interference

“…Among the most interesting B. cinerea control strategies to be implemented in nature on crops is the use of biocontrol microorganisms [ 199 , 200 , 201 , 202 , 203 ]. In-depth analysis of this complex topic is beyond the scope of this review.…”

Biocontrol and Enzymatic Activity of Non-Saccharomyces Wine Yeasts: Improvements in Winemaking

“…The main hurdle that microbial BCAs encounter is the expectation that they should behaves as a chemical fungicide in the field, with the same routine phenological application as synthetic fungicides. Under field conditions and depending on how microbial BCAs are formulated and applied, their consistency and efficacy may be severely compromised [16,33]. Microbial BCAs are living organisms with advantages such as specificity against certain pathogens, distinct modes of actions, and resilience potential, providing a better method of combatting pathogens.…”

“…Non-Saccharomyces wine yeasts, isolated from grape and/or wine fermentation environments, have different abilities, among them the potential to act as bioprotectants and biocontrol agents against phytopathogens [8][9][10][11][12] and wine spoilage organisms [13][14][15]. Biocontrol in wine grapes and wine comprises the use of selected microorganisms with antagonistic activity and/or their metabolites against other deleterious ones to reduce the need for chemical pesticides or wine preservatives, which can have negative effects on human health and the environment [3,16,17]. Therefore, non-Saccharomyces wine yeasts have potential as environmentally friendly tools to improve the sustainability aspects of winemaking.…”

Field and postharvest application of microencapsulated Yamadazyma mexicanaLPa14: anthracnose control and effect on postharvest quality in avocado (Persea americana Mill. cv. Hass)

“…7 Due to these concerns, there is great interest in the search for ecological and safe alternatives for preharvest anthracnose control. 8 Biocontrol agents (BCAs) such as yeasts are considered nonharmful, promising, environmentally friendly, and an effective control method for preharvest and postharvest phytopathogens. 9 Recently, Yamadazyma mexicana LPa14 was studied for the first time as a biocontrol agent in avocado fruits.…”