Author:
Nawu Takudzwa, Gwatidzo Odette Varaidzo, Rugare Joyful Tatenda, Gasura Edmore, Makaza William, Ngadze Elizabeth

Doi: 10.26480/faer.01.2022.07.11

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Fusarium oxysporum f.sp lycopersici is a soil borne pathogen of economic importance that reduces quality and quantity of tomatoes. Various fungicides have been utilized in the control of the pathogen however, resistance still remains a problem. However, biological control has been found as a promising alternative that suppresses F. oxysporum f.sp lycopersici. In vitro and in vivo experiments were carried out to determine the efficacy of Trichoderma harzianum as a bio-control agent against F. oxysporum. In the in vitro experiment, treatments (Trichoderma only, Dual culture, Fusarium only and Mancozeb) were laid in a randomized complete block design to evaluate radial mycelial growth of F. oxysporusm. Trichoderma harzianum significantly (p<0.001) reduced radial mycelium growth to 9.88 mm which is an inhibition of 86.8 % in a dual culture. On the other hand, Mancozeb (positive control) moderately reduced radial mycelium growth by 32.58% hence less effective compared to the Trichoderma treatment. Under greenhouse conditions, plants treated with 4 g T. harzianum exhibited least disease severity and incidence of 17.67 % and 43.7 %, respectively. High severity of 57.33 %, 80.67 % and incidence of 79.2 % and 85.4 %, respectively were recorded for positive and negative controls. In addition, 4 g T. harzianum treated plants recorded significantly higher plant height and total yield per plant for three weeks of harvest than the positive and negative control treatments. In conclusion, 4 g T. harzianum suppressed F. oxysporum development in tomato plants and further research can be done to study its effect on tomato plants under field conditions.