In this work, we studied the impact of harvesting time on Fusarium mycotoxin occurrence in spring wheat and the effect of mycotoxin contamination on the quality of these grains. The spring wheat grains (Triticum aestivum L.) were collected in 2016–2018 when the crop had reached full maturity, 10 ± 2 days and 17 ± 3 days after full maturity. The grain samples were analyzed for Fusarium infection and co-contamination with mycotoxins deoxynivalenol (DON), zearalenone (ZEA), and T-2 toxin (T-2), as well as the quality of the wheat grains (mass per hectolitre, contents of protein, starch, ash and fat, particle size index (PSI), falling number, sedimentation, wet gluten content, and gluten index). The occurrence of Fusarium spp. fungi and the mycotoxins produced by them in the grains was mostly influenced by the harvesting time and meteorological conditions. The correlations between Fusarium species and the mycotoxins produced by them in the grains of spring wheat showed F. graminearum to be a dominant species, and as a result, higher concentrations of DON and ZEA were determined. The co-occurrence of all the three mycotoxins analyzed (deoxynivalenol, zearalenone, and T-2 toxin) was identified in wheat. In rainy years, a delay in harvesting resulted in diminished grain quality of spring wheat, as indicated by grain mass per hectolitre and falling number. Negative correlations were found in highly contaminated grains between mycotoxins (DON, ZEA, and T-2) and falling number and grain mass per hectolitre values.

Mycosphaerella graminicola (Fuckel) J. Schröt. (anamorph Zymoseptoria tritici (Desm.) Quaedvlieg & Crous) causes Septoria leaf blotch disease of wheat. The disease can be responsible for yield losses of 30-50% and, when severe, requires management with a fungicide. Single picnidia isolates collected from different locations of Lithuania were tested in vitro for sensitivity to demethylation-inhibiting (DMI) fungicides epoxiconazole, cyproconazole and prothioconazole. Fungicide concentrations were chosen from the proposed Fungicide Resistance Action Committee (FRAC) methods. Microtitre plates with 96-wells were inoculated with suspensions of pycnidiospores taken from single pycnidia of leaves. In total, 196 isolates from 34 locations were tested over the three experimental years (2009)(2010)(2011). The results showed reduced sensitivity of M. graminicola isolates to epoxiconazole and cyproconazole. The average EC 50 values over three experimental years for epoxiconazole varied between 1.02 and 3.15 mg l -1 , for cyproconazole -1.51 and 10.66 mg l -1 . The sensitivity to prothioconazole of 64 isolates from 13 locations (2011) ranged from 0.43 to 32.28 mg l -1 . Results of field experiments (2007)(2008)(2009)(2010)(2011) showed that fungicides epoxiconazole and prothioconazole significantly reduced the area under the disease progress curve (AUDPC) values of Septoria leaf blotch compared with untreated plots in winter wheat. In most cases, a single fungicide application significantly increased grain yield and a thousand grain weight weight.

The seeds of the winter and spring wheat (Triticum aestivum L.) were subjected to a strong microwave electric field (SMEF) generated in a high power magnetron generator, working in a pulsed mode. Seed samples with different moisture contents (12, 15 and 18 %) were treated at the band 2.6, 5.7 and 9.3 GHz at 5, 10 and 20-minute exposures. Seed germination energy (GE), germination (G), abnormally germinated seeds (AG), germination index (GI) and seedling vigour index (SVI) were tested. The effect of SMEF on Tilletia caries infestation, plant productivity and seed sanitation was also explored. Seed treatment with SMEF did not sufficiently effect on winter wheat seed GE and G; however, the increase in AG and reduction in GI and SVI were observed. The negative effect on GI and SVI increased when seeds with higher humidity were treated. Treatment of winter wheat cv. 'Kovas' seeds, artificially inoculated with Tilletia caries, with SMEF showed a trend towards reduction of bunt infected ears. Seed treatment with SMEF stimulated grain yield increase and the bands 2.6 GHz for 20 min, 5.7 GHz for 10 min and 9.3 GHz for 5 and 10 min induced an increase in grain number and grain weight per ear. The efficacy of the chosen SMEF bands and exposition time on winter and spring wheat seed sanitation were contradictory. The SMEF treatment against wheat seed borne pathogens such as Phaeosphaeria nodorum (causal agent of Stagonospora glume blotch), Pyrenophora tritici-repentis (causal agent of tan spot) and Fusarium spp. (causal agents of seedling and adult plant foot and root rots and Fusarium head blight) gave conflicting and inconsistent efficacy results. The composition of most frequently isolated Fusarium species on SMEF treated winter wheat seeds was pertained to SMEF bands and exposition time.

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