Application of biostimulant products and biological control agents in sustainable viticulture: A review

Abstract

Current and continuing climate change in the Anthropocene epoch requires sustainable agricultural practices. Additionally, due to changing consumer preferences, organic approaches to cultivation are gaining popularity. The global market for organic grapes, grape products, and wine is growing. Biostimulant and biocontrol products are often applied in organic vineyards and can reduce the synthetic fertilizer, pesticide, and fungicide requirements of a vineyard. Plant growth promotion following application is also observed under a variety of challenging conditions associated with global warming. This paper reviews different groups of biostimulants and their effects on viticulture, including microorganisms, protein hydrolysates, humic acids, pyrogenic materials, and seaweed extracts. Of special interest are biostimulants with utility in protecting plants against the effects of climate change, including drought and heat stress. While many beneficial effects have been reported following the application of these materials, most studies lack a mechanistic explanation, and important parameters are often undefined (e.g., soil characteristics and nutrient availability). We recommend an increased study of the underlying mechanisms of these products to enable the selection of proper biostimulants, application methods, and dosage in viticulture. A detailed understanding of processes dictating beneficial effects in vineyards following application may allow for biostimulants with increased efficacy, uptake, and sustainability.

Nature‐based strategies to regenerate the functioning and biodiversity of vineyards

“…A biostimulant could be defined as a product that improves plant productivity or other F I G U R E 2 Conceptual links among nature-based strategies collectively aimed at improving the health of vineyards. agronomic characteristics such as tolerance to biotic or abiotic stresses, and whose said improvement is not due to its effect as a fertilizer (Gutiérrez-Gamboa et al, 2019;Jindo et al, 2022;Rouphael & Colla, 2020;Yakhin et al, 2017). Biostimulants can be mineral or biological substances.…”

“…In the case of microbial biostimulants, most of the previous research has focused on single strains or formulations of a few strains (Jindo et al, 2022;Yakhin et al, 2017). Many of these biostimulants are made of bacteria belonging to the genera Bacillus, Pseudomonas or Burkholderia, or mycorrhizal fungi (see Jindo et al, 2022 for a comprehensive overview of bacterial and fungal biostimulants and their main reported effects). Recent studies suggest that locally derived microbial formulations can be particularly effective in promoting crop production in low-fertility soils, while commercially available synthetic communities (SynComs) may perform better in high-fertility soils (Jiang et al, 2023).…”

“…The use of biostimulants has recently emerged as a useful tool to regenerate the functioning of croplands. A biostimulant could be defined as a product that improves plant productivity or other agronomic characteristics such as tolerance to biotic or abiotic stresses, and whose said improvement is not due to its effect as a fertilizer (Gutiérrez‐Gamboa et al, 2019; Jindo et al, 2022; Rouphael & Colla, 2020; Yakhin et al, 2017). Biostimulants can be mineral or biological substances.…”

“…Biostimulants can be mineral or biological substances. Treatment with complex mixtures of natural substances, including protein hydrolysates, natural extracts, humic acids and microorganisms, such as mycorrhizae and rhizobacteria, has also been shown to trigger biostimulant effects in plants (Gutiérrez‐Gamboa et al, 2019; Jindo et al, 2022; Rouphael & Colla, 2020; Yakhin et al, 2017).…”

Holistic understanding of the response of grapevines to foliar application of seaweed extracts

“…Seaweed extracts, or purified molecules from them, are able to induce defense reactions through a cascade of signaling events previously described (Delaunois et al, 2014;Bodin et al, 2020). However, despite the great interest in developing and testing new seaweed extracts as biostimulants, few well-characterized products with reliable performance are available on the market, with those that are deriving mainly from Ascophyllum nodosum (Jindo et al, 2022). Therefore, the objective of the current work is to provide an comprehensive overview of the vine response to seaweed application by studying the biostimulant efficiency of Ulva ohnoi and Rugulopteryx okamurae extracts through different layers (genetics, plant physiology, secondary metabolites and microbiology) to provide insights into their activity.…”