Biological weed control using Trichoderma polysporum strain HZ-31

To develop a potential bio herbicide, herbicide activity and crop safety of fungal strain HZ-31 isolated from naturally infected weed Cirsium arvense (L.) Scop. were investigated. The study was conducted in vitro and in vivo during the summers of 2017 and 2018. Strain HZ-31 showed broad-spectrum herbicidal activity, both in vitro and in vivo, when targeting Elsholtzia densa Benth., Polygonum kupathifolium L., Lepyrodiclis holosteoides (C.A. Mey.) Fenzl ex Fisch. & C.A. Mey., Avena fatua L., Chenopodium album L. and Polygonum aviculare L. Exposure to HZ-31 in vitro induced heavy levels of damage in the leaves of E. densa, A. fatua, and P. aviculare. Exposure to HZ-31 in vivo resulted in high mortality in E. densa, A. fatua, and P. lapathifolium. Although the exposure of various weeds to HZ-31 caused severe damage, the strain did not cause any deleterious effects in Vicia faba L. and Pisum sativum L., two of the five crops tested. Our results suggest that fungal strain HZ-31 could be a potential mycoherbicide candidate for weed control in V. faba and P. sativum fields. Based on its morphological characteristics and ITS nucleotide sequence analysis, the fungus was classified as Trichoderma polysporum (Louk:Fr.) Rifai. New perspectives for weeds control by T. polysporum and its use in V. faba and P. sativum crops were prospected, considering the bioherbicide selectivity described in this study.