In vitro inhibition of Fusarium solani by Trichoderma harzianum and biofertilizer

Paula Fernanda De Azevedo,Rodrigo Domiciano Marques,Ana Carolina De Almeida,Anderson Roberto Benedetti,Christiane Luciana Da Costa,Luis Eduardo Azevedo Marques Lescano,Mayra Costa Da Cruz Gallo De Carvalho Carvalho,Leopoldo Sussumu Matsumoto

doi:10.33448/rsd-v10i3.12994

Paula Fernanda De Azevedo, Rodrigo Domiciano Marques + Show 6 more

Open Access

https://doi.org/10.33448/rsd-v10i3.12994

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Abstract

Cassava root rot causes significant production losses. Difficulties of management, along with the lack of chemical fungicides officially registered by the Ministry of Agriculture, Livestock and Supply (MAPA), require alternative control methods. This study investigated the in vitro antagonistic activity of Trichoderma harzianum as well as a biological fertilizer MICROGEO® on Fusarium solani. The phytophatogenic strains of F. solani, called F1 and F2 were isolated from rotted cassava tubers and T. harzianum, strain ESALQ 1306, from a biological fungicide. Continuous liquid composting of bovine ruminal content, water and MICROGEO® produced the biological fertilizer. Dual culture method was used at the bioassay with T. harzianum. Sterilized (St) and unsterilized (USt) biological fertilizer were tested in different concentrations (% v/v) diluted in the culture media. Colony diameters were measured daily in order to establish the mycelial growth velocity index, inhibition percentage, aside from the sporulation rate and spore germination percentage. The mycelial growth of F. solani isolates was interrupted after hyphae encounter with T. harzianum, due to the occurrence of mycoparasitism, but without influence on the sporulation rate. Sterilized biological fertilizer induced no biocontrol, whereas the unsterilized product (concentration 2.5%) inhibited approximately 64% and 85% of the mycelial growth of isolates F1 and F2, respectively. Moreover, spore germination declined with increasing concentration. In conclusion, T. harzianum and the unsterilized biofertilizer showed in vitro antagonistic activity on F. solani.

Highlights

The capacity of adaptation to different cultivation conditions and the versatility of uses make cassava (Manihot esculenta Crantz) both socially and economically a highly relevant crop
3.2 Antagonist action of Trichoderma harzianum on Fusarium solani The dual culture assay of T. harzianum with F. solani isolates demonstrated an interruption in the mycelial growth of plant pathogens at the moment their hyphae meet with those of T. harzianum, on the 7th days after subculturing (DAS) (Table 1)
There was no inhibitory action of T. harzianum, since the Mycelial Growth Velocity Index (MGVI) of isolates F1 and F2 did not differ from the controls (Table 1)

Summary

Introduction

The capacity of adaptation to different cultivation conditions and the versatility of uses make cassava (Manihot esculenta Crantz) both socially and economically a highly relevant crop. From the economic point of view, it is the crop with the world's sixth highest production and Brazil is the fourth largest producer of cassava root (Conab, 2019). Diseases such as cassava root rot, caused by fungi of the genus Fusarium, affect the plant health and are responsible for significant yield losses, hampering sales (Boas et al, 2016). Aside from affecting the quality of the harvested roots, some species of the genus are able to produce mycotoxins, which can be harmful to plants, animals and humans These plant pathogens colonize alternative host plants and survive in the soil for long periods under adverse conditions, foiling an effective plant health management (Kim & Vujanovic, 2016)

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