Performance of fungicides on the control of fusarium head blight (Triticum aestivum L.) and deoxynivalenol contamination in wheat grains

Abstract

Fusarium head blight (FHB) is considered a disease of difficult control in a scenery of obstacles for its chemical control and due to the aggressiveness of its pathogen in producing toxins. Thus, the objective of this study was to verify if fungicides of different chemical groups, alone or in combination, are effective in controlling fusarium head blight and reducing deoxynivalenol (DON) contamination in wheat grains. In addition, pyraclostrobin alone was evaluated for possible changes on fusarium head blight intensity and DON accumulation reflecting on the yield. The experiments were conducted in the field, in a randomized block design, containing 11 treatments and four replicates, using the cultivar TBIO Toruk. The treatments were composed of the fungicides triazole, strobilurin and benzimidazole alone, besides the commercial mixture of triazole + strobilurin. Two fungicide applications were performed during the crop flowering. Fusarium head blight intensity, control efficacy, DON contamination and grain yield were evaluated. Data were subjected to analysis of variance (F-Test at 5%) and means were compared according to Scott-Knott test, at 5%. Carbendazim alone presented greater control efficacy in the two studied years (67% and 75%, respectively), differing from metconazole and pyraclostrobin. Pyraclostrobin at different doses and application stages changed fusarium head blight intensity, DON contamination and wheat grain yield.

Are DMI+QoI premixes applied during flowering worth for protecting wheat yields from Fusarium head blight? A meta-analysis

“…Our mean estimates of control efficacy for the premix PYRA + METC (64%) were very close to the efficacy reported other recent studies, not included in our analysis, such as a two-year study (62%) conducted in the north of RS state, Brazil (Bonfada et al 2019) and a four-year study (64.5%) conducted in the south of Paraná (Feksa et al 2019). In the latter, the premixes were applied following pathogen inoculation, differing from our dataset from natural epidemics.…”

“…Our study shows clearly the need to invest resources on the analysis of DON data. The limited number of studies testing the effect of DMI+QoI premixes, both from published and CFT sources, reporting DON data (Baseggio et al 2017;Bonfada et al 2019;Feksa et al 2019;Spolti et al 2013) prevents us from obtaining reliable estimates of mycotoxin reduction for large databases as elsewhere ( Paul et al 2018) . Thus far, there is very limited evidence of the effect of one or two applications of premixes, during flowering period, on FHB, yield and DON, which are composed of different combinations of QoIs and DMIs that can act differently (Blandino et al 2006;Feksa et al 2019;Paul et al 2018;Zhang et al 2009) .…”

Giberela e Desoxinivalenol: Qual a relação e como fungicidas podem ajudar?

“…However, according to other studies and reviews (PONTE et al, 2012;BONFADA et al, 2019;DUCATTI et al, 2022) and this study (Figure 1), the correlati on between FHB severity, incidence of Fusarium in the kernel, and DON accumulati on is positi ve but weak. It shows and reinforces that DON biosynthesis and accumulati on will not necessarily follow Fusarium contaminati on by the presence of Fusarium in wheat/kernels.…”

“…Besides yield reducti on, which was about 60% to 70% in South American fi elds (RANDHAWA et al, 2019) and 18.6% to 39.9% in Brazilian fi elds (REIS et al, 2016), FHB also decreases kernel quality due to mycotoxin biosynthesis and accumulati on by F. graminearum (BONFADA et al, 2019), which may reduce the commercial value of the crop up to 100% in many cases (MARIN et al, 2013). McMullen et al (2012), in a review focusing on FHB in barley and wheat, showed that the United States of America lost about US$ 7.67 billion due to the incidence of this disease from 1993 to 2001.…”

“…Therefore, the use of inefficient fungicides to control specific fungi, such as F. graminearum, inefficient doses, and fungicides in inappropriate periods, besides the incidence of biotic and abiotic stresses, might contribute to higher mycotoxin biosynthesis and accumulation (WEGULO, 2012;BONFADA et al, 2019). This might be the reason why the correlation between the FHB incidence and DON in wheat and barley kernels tends to be weak (PONTE et al, 2012;WEGULO, 2012).…”