Efficacy of the biocontrol agent Trichoderma harzianum ITEM 3636 against peanut smut, an emergent disease caused by Thecaphora frezii

Abstract

In this work, a bioformulation containing Trichoderma harzianum strain ITEM 3636, an effective biocontrol agent against the peanut pathogen Fusarium solani, was evaluated for control of peanut smut, an emergent disease caused by Thecaphora frezii. The performance of the bioformulation was evaluated during seasons 2014/2015 and 2015/2016 in experimental fields with history of peanut smut. Inoculation with T. harzianum ITEM 3636 significantly reduced the severity of peanut smut during both seasons by 17% and 25%, respectively. This is the first report where a consistent decrease of peanut smut symptoms is achieved in field experiments using a potential biological control agent. The identity of the causal agent of peanut smut was confirmed by sequencing the D1/D2 DNA region. T. harzianum ITEM 3636 caused significant increases in grain weight/plant in both years. Peanut smut and brown root rot are diseases that cause severe economic losses. Both causal agents may be present in the soil and, depending on environmental factors, cause disease. The T. harzianun ITEM 3636 bioformulation has high potential for controlling both diseases. Thus, the application of a single bioformulation could protect the health of peanut plants against two high impact pathogens.