This study was conducted under laboratory conditions to investigate the effects of herbicides (nicosulfuron, metribuzin and glyphosate) on the number of actinomycetes in soil and growth of several isolates of actinomycetes in vitro. The lowest tested concentrations equalled the recommended rates (1X), while the other three were five-fold (5X), ten-fold (10X) and fifty-fold (50X). Samples were collected for analysis 3, 7, 14, 30 and 45 days after herbicide application. Treatment with the two highest concentrations of herbicides (10X and 50X) caused a significant inhibition of the number of actinomycetes in soil and growth of the isolates in vitro. The obtained data indicated that the effect depended on the type of herbicide, application rate, duration of activity and actinomycetes isolate. The study suggests that herbicide applications in soil caused transient effects on the growth and development on actinomycetes community in soil.

Commercial production of the button mushroom, Agaricus bisporus (Lange) Imbach, is threatened by various pests and mycopathogenic microorganisms. Sciarid flies (Sciaridae) of the genus Lycoriella are considered as major pests, while major pathogens include the fungi Lecanicillium fungicola (Preuss), Zare and Gams, Hypomyces perniciosus Magnus, Cladobotryum spp., and Trichoderma aggressivum Samuels & W. Gams, the causative agents of dry bubble, wet bubble, cobweb, and green mold diseases, respectively. Control of mushroom pests and diseases has long relied on synthetic chemical pesticides. Pesticide resistance and various health and environmental issues have created a need for sustainable and eco-friendly alternatives to the use of synthetic chemical pesticides for mushroom pest and disease control. The concept of bioprotection, which involves using biological control agents (BCAs) and biopesticide products, offers a viable alternative. The entomopathogenic nematode Steinernema feltiae (Filipjev) and predatory mite Stratiolaelaps scimitus (Womersley) are the most important invertebrate BCAs, while the bacteria Bacillus thuringiensis Berliner, B. amyloliquefaciens, and B. velezensis stand out as the most widely used microbial BCAs/biopesticides. Azadirachtin- and pyrethrum-based products are the most important biochemical biopesticides. Bioprotection agents require inclusion in the integrated pest and disease management (IPDM) programs in order to achieve their full effectiveness.

The purpose of this study was to examine in vitro the herbicidal effect of an essential oil of dill (Anethum graveolens) on germination and early seedling growth of two parasitic flowering plants in the genus Cuscuta (Cuscuta campestris and C. epithymum), as well as its phytotoxic impact on germination and early seedling growth of two host plants (alfalfa and red clover). Chemical analysis of the essential oil extracted from dill leaves and flowers showed that carvone (51.69%) and limonene (39.88%) predominated. The results of a seed bioassay showed inhibitory effects of different concentrations (1%, 0.5%, 0.1%, and 0.01% v v-1) of the essential oil of dill leaves on germination and early seedling growth of both tested species of the genus Cuscuta. Germination of C. campestris seeds was inhibited between 67% and 94%, while seed germination of C. epithymum was inhibited between 67% and 100%. A similar inhibitory effect was observed regarding the seedling length parameter. Moreover, the bioassay results indicated significant phytotoxic effects of dill essential oil on the seed germination and early seedling growth of host plants. Red clover proved more sensitive as even the lowest concentration inhibited germination by 35%, while higher concentrations caused 70-100% inhibition. On the other hand, lower concentations inhibited germination of alfalfa seeds by 5%, while higher concentrations caused greater inhibition (36-100%). Future research should include both pot experiments and field micro-trials to determine herbicidal, i.e. phytotoxic, effects of dill essential oil on parasitic flowering plants and cultivated species.

Lycoriella ingenua (Dufour) is a major pest in mushroom facilities in Serbia and worldwide. The study aimed to determine the virulence (in vitro) and effectiveness (in vivo) of three Serbian native populations of entomopathogenic nematodes (EPNs) Steinernema feltiae (Filipjev), P9, K2, and ZŠT, compared to a commercial population of S. feltiae against L. ingenua, and their impact on mushroom yield. In vitro bioassays showed that seven days after exposure to a series of nematode suspensions (IJ cm⁻²), two of the three native (P9 and K2) populations and the commercial population of S. feltiae caused significant mortality of L₄ instar larvae of L. ingenua. The following LC_50s were estimated: 18.47, 15.77, and 11.48 IJ cm⁻² for P9, K2, and the commercial populations, respectively. These populations were further used for in vivo bioassays, where their IJs were applied as drench treatment twice (at the rate of 75 IJ cm⁻²) during casing time and seven days later. Control of L. ingenua larvae with the commercial population of S. feltiae was 85%, while the effectiveness of the native populations was 70%. The lack of adequate pest control measures emphasizes a need to promote local EPNs as biologically based and ecotoxicologically safe products.

Green mould, caused by Trichoderma aggressivum, is one of the major fungal diseases of button mushrooms. The main problems in chemical disease control include a lack of effective agents, the occurrence of pathogen resistance to pesticides, and the harmful impact on the environment. In an attempt to find a solution, the interaction between two beneficial microorganisms, Bacillus amyloliquefaciens B-241 (an antifungal agent) and Streptomyces flavovirens A06 (a yield stimulant), was investigated in vivo. The synergy factor (SF) was calculated as a ratio between the observed and expected impact on the yield or efficacy of disease suppression after artificial inoculation with T. aggressivum. The highest control of T. aggressivum was achieved by joint application of the two beneficial microorganisms. The additive interaction between microorganisms in efficacy against the pathogen was revealed. The largest yield was obtained in mushroom beds sprayed with the two beneficial microorganisms combined (B-241 80% and A06 20%). Regarding the impact on the yield, synergistic interaction between the two microorganisms was confirmed (SFs were 1.62 or 1.52). The introduction of optimized microbial combinations could create new possibilities for biorational edible mushroom protection, with improved yield and quality and reduced risks to human health and the environment.

The substrate for button mushroom (Agaricus bisporus) cultivation includes a highly complex microbiome. The aim of the study was to evaluate ecological interactions (synergistic, antagonistic, or additive) between a commercial population of the entomopathogenic nematode Steinernema feltiae (EPN) and beneficial microorganisms, bacterium Bacillus amyloliquefaciens B-241 (BA) or actinobacterium Streptomyces flavovirens A06 (SF). Their relationships were evaluated in efficacy against the pathogenic fungus Trichoderma aggressivum and the fungus gnat Lycoriella ingenua. Moreover, their impact on mushroom yield was estimated. The synergy factor was calculated as the ratio of observed to expected values regarding their efficacy against T. aggressivum/L. ingenua and influence on mushroom production. Additive relationships in efficacy against T. aggressivum were observed between EPN and BA or SF. As for the impact on yield, synergistic interactions were indicated between each beneficial microorganism and EPN. Considering suppression of L. ingenua, a mild antagonistic reaction between EPN and each beneficial microorganism was observed in plots without T. aggressivum and additive in plots inoculated with the pathogenic fungus, although high efficacy was achieved in all combinations (>80%). Tested native strains of both beneficial microorganisms could be combined with the commercial EPN strain for successful biological pest and disease control in mushroom production.