Controversial impact of experimental soil inoculant containing Beauveria bassiana and Metarhizium anisopliae on Sitophilus granarius

The insecticidal efficacy of the experimental bioinoculants (Natur Nova, Natur Agro Hungary Ltd., Hungary) containing Beauveria bassiana (Bals.-Criv). Vuill. and Metarhizium anisopliae Metschnikoff against stored product pests modelled by granary weevil, Sitophilus granarius L. was evaluated on wheat in laboratory tests. In order to comparability, two applications were also set up: one purely ash-treated grain treatment against wireworms and a soil-injected one. Our results confirmed that some biopesticides can exert unexpected effect on non-target arthropods. However, the examined biopesticides were as empirically effected against the target arthropods regarding wireworms. Nevertheless, the application exempt from ash of the examined bioinoculants Natur Nova containing B. bassiana and M. anisopliae were not suitable for the elimination of the stored product pests modelled by S. granarius. In contrast, the putative plant protection effect of these biopesticides was observed in the course of applying the agents in the recommended environment and pest species as well as when applying them with ash carrier.

Invasive plant benefits a native plant through plant-soil feedback but remains the superior competitor

Plant soil feedback (PSF) occurs when a plant modifies soil biotic properties and those changes in turn influence plant growth, survival or reproduction. These feedback effects are not well understood as mechanisms for invasive plant species. Eragrostis lehmanniana is an invasive species that has extensively colonized the southwest US. To address how PSFs may affect E. lehmanniana invasion and native Bouteloua gracilis growth, soil inoculant from four sites of known invasion age at the Appleton-Whittell Audubon Research Ranch in Sonoita, AZ were used in a PSF greenhouse study, incorporating a replacement series design. The purpose of this research was to evaluate PSF conspecific and heterospecific effects and competition outcomes between the invasive E. lehmanniana and a native forage grass, Bouteloua gracilis. Eragrostis lehmannianaPSFs were beneficial to B. gracilis if developed in previously invaded soil. Plant-soil feedback contributed to competitive suppression of B. gracilis only in the highest ratio of E. lehmanniana to B. gracilis. Plant-soil feedback did not provide an advantage to E. lehmanniana in competitive interactions with B. gracilis at low competition levels but were advantageous to E. lehmanniana at the highest competition ratio, indicating a possible density-dependent effect. Despite being beneficial to B. gracilis under many conditions, E. lehmanniana was the superior competitor.

The effect of seed density, variety and soil inoculant on the yield of soybean

The research was established in one growing season (2018), in 4 repeats, on 10 square meter random layout plots in the research farm of the Department of Field Crops Research of National Agricultural Research and Innovation Centre, in Szeged-Öthalom. In our investigation we used two different seeding rates (40 and 60 seeds m-2) on two soybean varieties (Pannónia kincse, Bahia). This study was carried out in inoculated field soil and non-inoculated field soil. We determined the yield and evaluated our results with ANOVA according to the different seeding density and varieties. From the results of our one-year survey, we could determine that Bahia had a higher yield than Pannonia kincse, which could be proved at 5% level of significance. Based on this data, we can see that the 60 seeds m-2 plots produced higher yields than the lower seed density (40 seeds m-2) plots. The results show that soybean yields increased as a result of soil inoculation.

The effect of soil inoculants on seed germination of native and invasive species

Successful reintroduction of native species through ecological restoration requires understanding the complex process of seed germination. Soil microbes play an important role in promoting native establishment and are often added to restoration sites during seed sowing. We tested the role of soil- and lab-grown bacterial inoculants on germination timing and percent germination for 19 species of plants commonly found in coastal California. Each species exhibited a different response to the inoculant treatments, but overall time-to-germination was longer and percent germination was lower with the soil inoculant compared with the control or other treatments. The invasive species in our study had the highest percent germination of all species and germinated faster than all native shrubs. Germination timing was negatively correlated with percent germination and with seed mass. Our results suggest that lab-grown inoculant and chemical treatment are effective at increasing germination in some native species, whereas soil inoculant is not. Given differences in germination timing between native and invasive species, restoration practitioners could consider using herbicide to treat areas seeded with native shrubs immediately following germination of invasive species without harming most natives, although germination timing and herbicides need further study in relation to microbial effects on seed germination.