Effect of Soil Biochar Amendment on Wheat Resistance to Fusarium Head Blight and Mycotoxin Contamination.

Mycotoxin contamination of food and feed is among the top food safety concerns. Fusarium head blight (FHB) is one of the most important diseases of wheat and other cereal grains. Fusarium graminearum, the fungal pathogen responsible for FHB, reduces crop yield and results in contamination of grain with mycotoxins called trichothecenes that can be deleterious to animal health. F. graminearum like other Fusarium spp. efficiently colonizes field crop residues such as wheat stubble and maize stalks. These pathogen reservoirs are primary sources of inoculum for FHB epidemics in wheat. Soil amendment with biochar can confer multiple benefits to plants including increased productivity and enhanced stress resistance. The objective of this study was to test whether biochar could enhance wheat resistance to F. graminearum disease and reduce trichothecene contamination.  Since biochar has also been shown to promote the growth of beneficial microorganisms in the rhizosphere, we further assessed the potential of biochar as a carrier system for the biocontrol agent Trichoderma harzianum which is known to be effective against several fungal soilborne plant pathogens including F. graminearum. Preliminary results from greenhouse trials indicate that amending soil with biochar and ascorbic acid is sometimes effective in reducing disease incited by F. graminearum in wheat.