terclim by ICS banner
IVES 9 IVES Conference Series 9 Improving shelf life of viticulture-relevant biocontrol and biostimulant microbes using CITROFOL® AI as liquid carrier

Improving shelf life of viticulture-relevant biocontrol and biostimulant microbes using CITROFOL® AI as liquid carrier

Abstract

Bacillus velezensis and Trichoderma harzianum are relevant microorganisms used in viticulture as biocontrol agents against pathogens of trunk (e.g. Phaeoacremonium minimum), leaves (e.g. Plasmopara viticola) or fruit (e.g. Botrytis cinerea), or as biostimulants, improving the resilience of plants against biotic or abiotic stressors through different direct and non-direct interactions.
In this biotechnological approach, formulation plays a crucial role.  Controlling water activity in the product, thus stabilising microbial viability is key to ensuring effective application.  We present the benefits of the citrate ester CITROFOL® AI (triethyl citrate) as a novel bio-based carrier liquid in microbial formulations. CITROFOL® AI is safe for humans and the environment, thus offering a promising base for sustainable treatments in viticulture.
Commercial products containing B. velezensis and T. harzianum formulated as wettable powders (WP) or suspension concentrates (SC) were used for viability tests and compared with the same microorganisms prepared as dispersion concentrates (DC) 1:10 ration in CITROFOL® AI. The formulations were subjected to a demanding storage test at 40°C for 24 weeks. Microbial viability was monitored by plate counting periodically.
B. velezensis showed a high overall robustness during storage. However, comparing liquid products, the cell viability in the SC formulation declined by approximately one order of magnitude more than in the DC formulation in CITROFOL® AI. T. harzianum generally was highly susceptible during storage. However, the cell viability after 24 weeks was two orders of magnitude higher when formulated as DC in CITROFOL® AI compared to the WP. Thus, CITROFOL® AI improved the shelf life of both microorganisms tested.

DOI:

Publication date: June 13, 2024

Issue: Open GPB 2024

Type: Poster

Authors

Teresa Berninger1, Carolin Stern1, Victoria Sevillano, Óscar González-López2*

1 Jungbunzlauer Ladenburg GmbH
2 University of La Rioja, Department of Food and Agriculture

Contact the author*

Keywords

Formulation, Viticulture, Citrate ester, Biocontrol, Biostimulant

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

Aroma composition of mono-varietal white wines for the production of Custoza

AIM: The appellation “Bianco di Custoza” or “Custoza”, born in 1971, is one of the oldest white wines Protected Designation of Origin in Italy.

Effects of organic mulches on the soil environment and yield of grapevine

Farming management practices aiming at conserving soil moisture have been developed in arid and semiarid-areas facing water scarcity problems. Organic mulching is an effective method to manipulate the crop-growing microclimate increasing crop yield by controlling soil temperature, and retaining soil moisture by reducing soil evaporation. In this sense, the effectiveness of different organic mulching materials (straw mulch and grapevine pruning debris) applied within the row of a vineyard was evaluated on the soil and on the vine in a Tempranillo vineyard located in La Rioja (Spain). Organic mulches were compared with a traditional bare soil management technique (based on the use of herbicides to avoid weed incidence). Mulching coverages favourably influenced the soil water retention throughout all the grapevine vegetative cycle. However, the soil-moisture variation was not the same under different mulching materials, being the straw mulch (SM) the one that retained more water in comparison with grapevine pruning debris (GPD) based-cover. The changes of soil moisture in the upper surface layer (0–10 cm) were highly dynamic, probably due to water vapour fluxes across the soil-atmospheric interface. However, both, SM and GPD reduced these fluctuations as compared with bare soils. A similar trend occurred with soil temperature. Both organic mulches altered soil temperature in comparison with bare soil by reducing soil temperature in summer and raising it in winter. Moreover, the same buffering effect for the temperature on the covered soil also remains in the deeper layers. To conclude, we could see that organic mulching had a positive impact on soil-moisture storage and soil temperature and the extent of this effect depends on the type of mulching materials. These changes led to higher rates of photosynthesis and stomatal conductivity compared to bare soils, also favouring crop growth and grape yields.

What about oxygen transfer during wine aging in barrels?

During wine aging, several complex phenomena of gas transfer take place in barrels due to the wine/oak contact. The efficiency of this gas transfer varies according to oak wood’s intrinsic physical properties. This research aims to better understand oxygen transfer phenomena through dry oak staves and especially through stave gaps, in order to reevaluate the importance of barrel-making on a barrel’s supply of oxygen. Experimentation was based on the development of an innovative permeameter of laboratory scale, for which the principal operating conditions concerning applied pressure, the choice of liquid phase/gas phase, and the grain type of oak are taken into account and investigated. With a specially developed tightening system, the existing pressure at stave gaps in a barrel could be reproduced on a laboratory scale in order to estimate its influence on oxygen transfer efficiency.

Evaluation of shelf life of white wines in aluminium bottle: a modelling approach

Aluminum is a particularly interesting material for packaging because it is environmentally sustainable, lighter than standard glass bottles, and protective against light radiation [1].

Sensory impact of acetaldehyde addition in Syrah red wines

Acetaldehyde is a volatile carbonyl compound synthetized by yeast during alcoholic fermentation, but it can also be formed by oxidation of ethanol during wine aging [1]. At low concentration, it enhances the fruity aroma, however, at higher levels, it can generate the appearance of notes of bruised and rotten apple [2]. From a chemical point of view, acetaldehyde is a reactive low-