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.

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 m²), 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.

In this study, the effects of organic powder ofCinnamomum zeylanicumon the development ofBotrytis cinereaand 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 inhibitB. cinereagrowth and also has a stimulating effect for tomato plants.

The potential of silicon used in two forms, two methods and three cultivars of spring wheat cultivated under organic farming conditions is high, as it helps plants to alleviate abiotic stresses. The research hypotheses of paper were the assumptions that the effectiveness of silicon may differ not only by the form of silicon and the method of its application, but also by the variety of common wheat and different water conditions in the soil during the growing season. These hypotheses were confirmed. The aim of this study was to determine the effectiveness of liquid and powder silicon forms and different methods of application in three cultivars (Harenda, Serenada and Rusałka) of spring wheat organically grown under a specific field experiment in water stress vs. no stress conditions. The water stress of plants was assessed on the basis of the sum of precipitation in the winter–spring and vegetation season in each year. The differences in water availability for the plants in the experimental years were confirmed. Silicon (Si) was used for seed dressing and/or for leaf spraying. In the first case, the powdered form of Si was used at a dose of 0.5 kg/100 kg of seeds; it was used together with the liquid form at a dose of 0.5 L/100 kg of seeds, and in the second, the liquid form of Si was used at a dose of 0.5 L per 200 L of water per hectare; spraying was carried out at the following plant development stages: three tillers detectable, the first node and the flag leaf. The application of Si positively influenced the wheat yield depending on the method of Si application, wheat variety and severity of water stress. The cultivar Harenda was more susceptible to lower water content in the soil than the cultivars Rusałka and Serenada. Under conditions of water stress, the use of Si slowed the development of young Harenda plants, but ultimately, the variety increased its grain yield to a greater extent than the other two varieties. The lowest weight of a thousand grains (TGW) was found in the Harenda variety; however, Si treatment improved this parameter. Si increased the yields of the three wheat varieties, and the highest were harvested in plots with combined Si treatments. The yields of the Rusałka and Serenada cultivars on these plots were 14 to 28% higher compared to the control. Harenda was the least fertile variety, but it increased its yield more than the other two varieties. This variety increased its yield in 2018 (year of average rainfall) by 26% from 2.92 to 3.94 tons per hectare, and in 2019 (a year of drought) by 42% from 1.66 to 2.87 tons per hectare. It can be concluded that Si improves the wheat yield, and its efficiency depends on the scale of water stress, the method of application and the variety. The simplest and most adaptable method of Si application is seed dressing and has prospects for wider application, especially in organic farming.

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.