The role of biocontrol products is expected to increase worldwide consumer demand and facilitate the implementation of sustainable agricultural policies. New biocontrol agents must allow for an effective crop-protection strategy in sustainable agriculture. Yeasts are microorganisms living in various niches of the environment that can be antagonists of many plant pathogens. Yeasts rapidly colonize plant surfaces, use nutrients from many sources, survive in a relatively wide temperature range, produce no harmful metabolites and have no deleterious effects on the final food products. Hence, they can be a good biocontrol agent. In this paper, the biological characteristics and potential of yeast are summarized. Additionally, the mechanisms of yeasts as plant-protection agents are presented. This includes the production of volatile organic compounds, production of killer toxins, competition for space and nutrient compounds, production of lytic enzymes, induction of plant immunity and mycoparasitism. The mechanisms of yeast interaction with plant hosts are also described, and examples of yeasts used for pre- and postharvest biocontrol are provided. Commercially available yeast-based products are listed and challenges for yeast-based products are described.

Cinnamon is widely used as a food spice, but due to its antibacterial and pharmacological properties, it can also be used in processing, medicine and agriculture. The word “Cinnamon” can refer to the plant, processed material, or an extract. It is sometimes used as a substance, and sometimes used as a mixture or as compounds or a group. This article reviews research into the effectiveness of various forms of cinnamon for the control of plant diseases and pests in crops and during storage of fruit and vegetables. Cinnamon acts on pests mainly as a repellent, although in higher doses it has a biocidal effect and prevents egg-laying. Cinnamon and its compounds effectively hinder bacterial and fungal growth, and the phytotoxic effects of cinnamon make it a possible herbicide. This article presents the wide practical use of cinnamon for various purposes, mainly in agriculture. Cinnamon is a candidate for approval as a basic substance with protective potential. In particular, it can be used in organic farming as a promising alternative to chemical pesticides for use in plant protection, especially in preventive treatments. The use of natural products is in line with the restriction of the use of chemical pesticides and the principles of the EU’s Green Deal.

In this study, the effects of organic powder of Cinnamomum zeylanicum on the development of Botrytis cinerea and its influence on tomato plants were evaluated. The cinnamon bark powder and its water suspensions and filtrates were used at 0.5 and 1% rates. After 6 days of the start of an in vitro experiment the mycelium growth was inhibited by both 0.5 and 1% cinnamon water filtrates-to a greater degree in the case of the higher concentration, by 54.4 and 81.4%, respectively. Spraying with cinnamon water filtrates positively influenced the growth of plants both in the greenhouse and the field. Antifungal activity of cinnamon was proved in the greenhouse tests-the disease symptoms of grey mould on infected tomato plants decreased. The fresh weight of non-inoculated tomato plants treated with cinnamon filtrates was significantly higher than control plants (17.17 g compared to 12.83 g) showing a stimulating effect of cinnamon filtrates. In the case of inoculated plants due to treatment, their weight increased from 7.83 to 10.50 g. In the field experiment, tomato plants sprayed six times with cinnamon were better developed than the control plants. The most significant effect was observed for Hamlet variety-the mean number of leaves was higher by 27.3% and the mean number of branches by 19.7% compared to the untreated control plants. Thus it was proved that cinnamon powder has potential to inhibit B. cinerea growth and also has a stimulating effect for tomato plants.

Application of silicon (Si) could greatly boost wheat growth and yield by mitigating abiotic stress, especially drought. Aim The objective of this study was to determine the effect of silicon products in different forms and methods of its application on growth and yield of spring wheat cultivated under organic farming regime. Methods A field experiment was conducted in the period of 2017-2018 on a research farm. The impact of different methods of application of powder and liquid forms of Si products to soil, leaves and combined methods of application (to soil and leaves) on growth parameters and yielding of spring wheat was evaluated. The treatments consisted of the recommended doses of two Si products-Adesil and ZumSil at 10 kg and 0.3 l/ha, respectively. The effect of silicon was assessed by measuring emergence and height of plants, number and weight of ears, as well as the SPAD index and yield. Results The number of plants emergence (316-321 seedlings per 1 m 2), the number of spikes and the height of plants were the highest after application of the liquid form of silicon, regardless of the method of application. The yield was statistically higher after the combined and foliar applications of liquid form of silicon (4.97 and 4.84 t/ha, respectively). The powder silicon form was similar effective when was used as the combined application (to soil and leaves) (5.35 t/ ha). Conclusions Si stimulates growth of wheat enhancing number of ears and plant height, increases yields of organically grown spring wheat, a liquid Si formulation (solution of monosilicic acid) is more effective than a powder Si formulation (diatomaceous earth). Soil and foliar Si application is more effective than soil or foliar application.

Virginia mallow is a plant from the central and eastern states of North America. A large amount of high quality biomass obtained from V. mallow led to interest in this plant for bioenergy purposes. Unfortunately, high incidence of white rot disease caused by Sclerotinia sclerotiorum destroyed plantations of this plant. In previous attempts, various control strategies were not successful and all treatments failed (including the use of Coniothurium minitans). The aim of the study was to find and evaluate yeast-like fungi for biocontrol of S. sclerotiorum, evaluate the optimal thermal condition for biocontrol efficacy, and describe possible modes of action of potential biocontrol organisms. In dual bioassay test with 19 strains of yeast-like fungi with S. sclerotiorum, antagonistic potential were obtained. At different temperatures variations in antagonistic activity of yeast-like fungi were observed. At all tested temperatures (i.e., 4, 12, and 23°C), positive results were obtained. Extracellular enzymes were produced by the majority of antagonistic yeast, such as: amylases (the most frequent), chitinases, proteases, pectinases and xylanases. In this research, reduction in white rot symptoms on V. mallow stems was significant (P < 0.05). The highest inhibition of disease was observed after treatment with strains (114/64) Candida albidus and (117/10) Pichia anomala.Key words: bioenergy crops, yeast, biocontrol, Sclerotinia sclerotiorum, Sida hermaphrodita, antagonistic activity.Résumé : La mauve de Virginie est une plante originaire des États du centre et de l'est d'Amérique du Nord. L'abondante quantité de biomasse de haute qualité qu'on en tire a fait en sorte qu'on s'intéresse à sa culture pour la production de bioénergie. Malheureusement, la forte incidence de pourriture blanche attribuable à Sclerotinia sclerotiorum a détruit les peuplements. Les tentatives antérieures de lutte selon diverses méthodes n'ont pas donné de bons résultats et tous les traitements se sont soldés par un échec (y compris le recours à Coniothurium minitans). La présente étude avait pour buts de trouver puis d'évaluer des cryptogames semblables aux levures qui permettraient de lutter biologiquement contre le parasite, d'établir les conditions thermiques idéales pour cela et de décrire les modes d'action possibles des organismes pouvant servir à la lutte biologique. Un antagonisme potentiel a été observé lors de l'essai biologique double réalisé avec 19 souches de cryptogames de type levure sur une culture de S. sclerotiorum. Cette activité antagoniste varie avec la température. Des résultats positifs ont été obtenus à toutes les températures testées (4, 12, et 23°C). La plupart des levures antagonistes synthétisent des enzymes extracellulaires comme des amylases (le plus souvent), des chitinases, des protéases, des pectinases et des xylanases. La diminution des symptômes de pourriture blanche sur la tige de la mauve de Virginie observée durant ces recherches est significative (P < 0,05). Le plus fort degré d'inhibition de la m...