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The environment can have a crucial influence on soybean production in particular regions, even more so when production environments are different from breeding environments. Therefore, soybean cultivars must be evaluated in field trials at various locations in order to explore the duration of the growing period and capacity of yield, which is based on interactions between genotype and environment. Seven soybean cultivars originating from five European countries were evaluated for thousand-seed weight, seed, protein and oil yields and protein and oil contents in five environments in Slovenia. Yield stability of seed, protein and oil was determined in order to select best genotype. Results showed that cultivar and environment had a significant impact on all measured variables. In almost all tested environments the best seed, protein and oil yielding cultivars were ES Mentor (3425-5628 kg seed/ha, 1280-2192 kg protein/ha, 640.8-918.9 kg oil/ha) and NS Mercury (3468-5342 kg seed/ha, 1266-2071 kg protein/ha, 618.6-880.7 kg oil/ha). The highest average protein content was found in NS Favorit (41.0% of DW). Volma had the highest average oil content (20.2%). Three yield stability indices were used to assess yield stability; in terms of Shukla?s variance (?i2) and S square Wricke?s ecovalence (Wi2), Josefine turned out to have most stable seed and oil yields, while ES Mentor had most stable protein yields. Regarding Kang?s yield stability (YSi), which makes simultaneous selection for mean yield and stability and is therefore most relevant for practical usage, ES Mentor, NS Mercury and NS Favorit were selected as superior genotypes regarding stability of seed, protein and oil in this study. Correlation analysis of some chosen traits showed different interdependence between measured variables depending on the environment. As expected, protein and oil contents were negatively correlated, yet this was only significant in one environment. The results of this study pointed out that among the seven tested cultivars, ES Mentor, NS Mercury and NS Favorit were best genotypes and are highly recommended for usage in soybean production in Slovenia.

The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera, Chrysomelidae), is an important insect pest of maize in North America and Central and Eastern Europe. In Central Europe, the larvae emerge in May and its three instars feed intensively on maize roots in June, causing plant lodging that leads to a loss of economic yield. A three-year field experiment (2016–2018) was conducted to compare the effectiveness i) of soil-applied granular insecticide based on the active ingredient tefluthrin, ii) of maize seeds dressed with thiacloprid, and iii) entomopathogenic nematodes Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae, product Dianem) against WCR larvae. An additional treatment with alcohol ethoxylate (i.e., soil conditioner) mixed with entomopathogenic nematodes was performed in 2017 and 2018 to check for any increase of entomopathogenic nematodes’ effectiveness. Field tests were carried out in two fields infested naturally with a WCR pest population, one in Bučečovci (Eastern Slovenia) and the other in Šmartno pri Cerkljah (northern Slovenia), exhibiting dissimilar pedo-climatic conditions and soil pest densities. The treatments were performed in five replicates per experiment in each year. The efficacy of the treatments was very similar at both locations, despite the approximately five-fold lower WCR soil pest densities in northern than in eastern Slovenia, as well as being constant over time. The largest number of WCR beetles was observed in the negative control, followed by that of beetles subjected to thiacloprid treatment (insignificant decrease taking into account the entire three-year dataset). Treatments with tefluthrin (44.1 ± 11.7%), H. bacteriophora (46.2 ± 7.4%), and H. bacteriophora + alcohol ethoxylate (49.2 ± 1.8%) significantly decreased the numbers of emerging beetles. Treatments of thiacloprid, H. bacteriophora, and H. bacteriophora + alcohol ethoxylate additionally led to significantly increased maize plant weights. Furthermore, entomopathogenic nematodes were able to persist in maize fields for almost five months at both experimental locations in silty and sandy loam soils. It was concluded that the control of WCR larvae in maize using the entomopathogenic nematode H. bacteriophora is as effective as a tefluthrin treatment, and could thus offer a sustainable Diabrotica v. virgifera biological control management option in Europe.

Four wheat cultivars with different levels of tolerance to Fusarium head blight (FHB) were grown in small plots and were inoculated with spores of Fusarium fungi during the anthesis. The harvested grain was cleaned by a special cleaner which separated it in 4 size fractions: F1 ->2.4 mm, F2 -2.0-2.4 mm, F3 -1.8-2.0 mm, F4 -<1.8 mm. These were further divided manually in four sub-fractions according to the rate of FHB symptom expression, i.e. grain without any visible symptoms, grain with changes in colour without changes in shape, grain with changes in colour and moderate changes in shape or size, and heavily infected malformed grain. Deoxynivalenol (DON) content in grain of different fractions was determined by high-performance liquid chromatography with UV detection (HPLC-UV) analysis. Comparisons between initial DON content before cleaning and DON content in individual fractions after cleaning were made. The cleaning efficacy (rate of DON content reduction) due to the cleaning and separating of grain in size fractions was higher in semi-tolerant and susceptible cultivars than in FHB tolerant cultivar. Due to the low cleaning efficiency, cleaned grain of tolerant cultivar (without any symptom of FHB), contained twice more DON (870-1350 µg kg -1 ) than cleaned and apparently healthy grain of semi-tolerant cultivar (160-570 µg kg -1 ); its DON content was comparable to that of the susceptible cultivar (905-1140 µg kg -1 ). Our results indicate that FHB tolerant cultivars may contain a high proportion of grain which is apparently healthy, but contains excessive DON levels. Such tolerant cultivars can contribute a lot to minimisation of yield loss caused by FHB, yet they may present a potential health hazard of organic whole-grain flour produced in non-industrial grain processing systems.

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