Fusarium head blight incidence and detection of Fusarium toxins in wheat in relation to agronomic factors

Abstract

We investigated incidences of Fusarium head blight (FHB) and concentrations of six mycotoxins (deoxynivalenol, nivalenol, 3-acetyldeoxynivalenol, T-2 toxin, HT-2 toxin and zearalenone) in wheat from 2010 to 2013. Field trials were conducted at the Experimental Station of Cultivar Testing in Chrząstowo, Poland (53 o 11'N, 17 o 35'E). We examined the effects of four agronomic factors, including pre-crop type (corn, sugar beets and wheat), date of sowing (late autumn: November 8-December 9 or spring: March 29-April 19), fungicidal application (untreated or treated with two applications) and cultivar (Monsun, Cytra), on FHB index (FHBi) and mycotoxin levels in order to minimize the risk of wheat grain contamination by mycotoxins via integrated pest management methods. The dominant Fusarium species observed on wheat heads were F. culmorum, F. avenaceum (Gibberella avenacea) and F. graminearum (Gibberella zeae), at 21.1%, 17.2% and 7.1%, respectively. A monthly rainfall sum of 113.9 mm and a relatively low air temperature (monthly average 15.5°C) resulted in the highest FHBi in untreated wheat (25.1%). Agronomic factors crucial for the FHB incidence were the pre-crop, fungicidal treatments and cultivar selection. In wheat planted after wheat or corn, the FHBi was higher compared with a precrop of sugar beet. A double application of fungicides at BBCH 30-32 with prothioconazole and spiroxamine and at a BBCH 65 with fluoxastrobin and prothioconazole effectively reduced the FHBi and mycotoxin concentrations, respectively, in grain. The cultivar 'Cytra' had a greater FHBi (10.4%) than 'Monsun' (4.6%), and grain infestations by Fusarium species were also greater in 'Cytra', at 16.5%, than in 'Monsun', at 11.2%. Untreated cv. Cytra grown after corn in spring produced grains with the highest amounts of the mycotoxins, deoxynivalenol, 103, 17.5 and 5.53 μg/kg, respectively). Total mycotoxin levels in wheat were correlated with five determinants: duration of the period between the end of flowering and the beginning of kernel abscission, FHBi, F. culmorum isolation, G. zeae isolation and Fusarium ratio (FR) as a % of total mould isolations. Although, the mean concentration of mycotoxins in grain did not exceed the maximum permissible values for unprocessed wheat our study suggests necessity to monitor and mitigate FHB risk for susceptible cultivars, when wheat spring sowing follows corn or wheat.

What influences the composition of fungi in wheat grains?

“…The impact of temperature was not evaluated because the average temperatures in the crucial period of ear infection were similar throughout all investigation years and did not exceed 17-19°C. The present investigation showed that F. avenaceum was the dominant species, which agrees with several other findings [25][26][27]. Similarly, a high occurrence of F. poae was detected in our research, which also supports the data in the literature [22,28].…”

“…The importance of crop rotation was highlighted by Wenda-Piesik et al [27], where an increasing proportion of Fusarium spp. was detected in wheat grains after the precropping of wheat and maize.…”

Impact of Fungi Co-occurrence on Mycotoxin Contamination in Maize During the Growing Season

“…This was probably due to differences in rain fallen in the 2 years considered; in fact, Fusarium Head Blight (FHB) is strongly dependent on specific weather condition (Doohan et al, 2003), mainly rainfall and temperature. A previous study underlined that a monthly rainfall sum of 113.9 mm and a monthly average temperature of 15.5°C are the best conditions for FHB occurrence (Wenda-Piesik et al, 2017).…”

Fusarium diseases: biology and management perspectives

“…Delaying optimal sowing date by 20-25 days increased Fusarium disease index under central European conditions in both susceptible and tolerant winter wheat cultivars, whereas increasing sowing density from 400 to 600 germinated seeds/m 2 did not show differences (Gorczyca et al 2018). However, in cultivars that do not need vernalization, a delay in sowing dates to late autumn or early spring did not have an effect on Fusarium disease index or DON contamination (Wenda-Piesik et al 2017).…”

“…The values vary widely between 10% and 50%, depending on the weather conditions and Fusarium populations (Kikot et al 2011;Xu and Nicholson 2009). Likewise, it has been shown that agricultural practices such as crop rotation, tillage, sowing date, fungicide treatment, cultivar, fertilizer source, irrigation regimes and overall production system (conventional vs organic) have an influence on the final DON concentration in both wheat and barley (Bernhoft et al 2012;Wenda-Piesik et al 2017). In the case of FCR, yield reductions can reach up to 26% in Australia and 50% in the USA (Liu and Ogbonnaya 2015).…”