The impact of tillage and fertilization on Fusarium infection and mycotoxin production in wheat grains.

Abstract

Fusarium head blight (FHB) is a worldwide disease of small grain cereals, which reduces grain yield and its quality. The aim of this study was to identify the influence of different tillage and fertilization practices on winter and spring wheat grain infection with Fusarium fungi and contamination by mycotoxins – deoxynivalenol (DON), zearalenone (ZEN) and T-2 toxin. A two-factor field experiment was carried out at the Lithuanian Institute of Agriculture during the period 2005–2008. The internal grain infection with Fusarium fungi were quantified using agar tests. Purified colonies were identified using different manuals. The mycotoxins were analyzed using ELISA method. Meteorological conditions were not conducive to Fusarium head blight development during the 2005–2008 period, therefore Fusarium infection level was very low in harvested winter wheat grain (0–7.1%) and moderate in spring wheat grains (27.3–41.3%). The concentrations of DON (<100–166.3 μg kg-1), ZEN (<10–10.8 μg kg-1) and T-2 toxin (<7.5–13.2 μg kg-1) in winter wheat grain samples most often were close to the limit of detection, while in spring wheat samples they were slightly higher. Tillage systems had no clearly evident influence on Fusarium infection level; however, some significant differences in the mycotoxin production were observed. The concentrations of DON (2008) and ZEN (2006 and 2008) in spring wheat and T-2 toxin (2006) in winter wheat significantly correlated with the number of productive tillers or number of plants m-2 and were significantly lower in no-tillage system. A significant influence of high fertilizer rates on spring wheat grain infection with Fusarium spp. was observed in 2007, and similar trends were found in 2006 and 2008. Higher concentrations of trichothecene producers were detected in the spring wheat grain from the conventionally tilled treatments applied with higher fertilizer rates.