Presence of deoxynivalenol in winter wheat treated with fungicides

Abstract

Natural occurrence of Fusarium spp. and concentrations of mycotoxin deoxynivalenol (DON) in the grain of the winter wheat moderately susceptible to Fusarium head blight (FHB) has been studied. Grain samples were collected from wheat crops intended mainly for human consumption. All wheat crops were treated with fungicides before (a.i. flutriafol - formulated as Fluoco, applied in dose of 0.5 l ha-1) and during the flowering phase of growing (a.i. thiophanate-methyl + epoxiconazole formulated as Eskorta plus and a.i. thiophanate-methyl formulated as Funomil, applied in doses of 0.75 and 0.5 l ha-1, respectivily). Among of Fusarium species only F. graminearum, as a well known producer of DON, was identified. This fungus was identified in 15 of 19 samples (78.9%) with incidence in positive samples of 2 to 28% (average, 14.0%). Presence of DON was established in 13 of a total 19 investigated wheat grain samples (68.4%). In positive samples DON was detected in concentrations from 69 to 918 μg kg-1 (average, 478 μg kg-1). DON showed a significant and positive correlation at P≥0.05 with grain moisture content (r = 0.52*). Between the frequency of F. graminearum and concentration of DON and between the frequency of F. graminearum and grain moisture content, positive correlation was determined, but without statistical significance (r = 0.44 and r = 0.29, respectively).

U radu je proučavana prirodna pojava Fusarium spp. i koncentracija mikotoksina deoksinivalenola (DON) u zrnu ozime pšenice srednje osetljive prema fuzariozi klasa (FHB). Uzorci zrna su prikupljeni sa proizvodnih useva pšenice namenjene uglavnom za ljudsku upotrebu. Svi usevi pšenice bili su tretirani sa fungicidima pre (a.m. flutriafol - formulisana kao preparat Fluoco, primenjen u dozi 0,5 l ha-1) i tokom cvetanja biljaka (a.m. tiofanat-metil + epoksikonazol formulisana kao preparat Eskorta plus i a.m. tiofanat-metil formulisana kao Funomil, primenjeni u dozi 0.75 i 0.5 l ha-1, respektivno). Među Fusarium vrstama jedino je identifikovana F. graminearum, koja je poznati producent DON. Ova gljiva je bila identifikovana u 15 od 19 uzoraka (78.9%) sa incidencom od 2 do 28% (prosek 14.0%) u pozitivnim uzorcima. Prisustvo DON je utvrđeno u 13 od ukupno 19 proučavanih uzoraka pšenice (68.4%). U pozitivnim uzorcima DON je detektovan u koncentracijama od 69 do 918 μg kg-1 (prosek 478 μg kg-1). DON je pokazao značajnu i pozitivnu korelaciju pri P≥0.05 sa sadržajem vlage zrna (r = 0.52*). Između učestalosti F. graminearum i koncentracije DON i učestalosti F. graminearum i sadržaja vlage zrna utvrđena je, takođe, pozitivna korelacija ali statistički nije značajna (r = 0.44 i r = 0.29, respektivno).