The use of non-host crops in rotations with tobacco is a component of an IPM strategy used to suppress root-knot nematode (RKN) populations. Nematode damage usually predisposes infected plants to other soil-borne pathogens, such as Fusarium spp. and Rhizoctonia spp. resulting in disease complexes that are more damaging than either on its own. In Zimbabwe, low hectarages have constrained the ability for growers to practise the recommended rotations and the monocropping has led to the re-emergence of root-knot nematode disease complexes on tobacco. Rotation crops notably sunhemp and Katambora grass have been recommended for the control of plant parasitic nematodes but there is need to control soilborne pathogens as well. The objective of this trial was to evaluate the efficacy of Sunhemp and Trichoderma harzianum 77 on root-knot nematodes and soreshin (Fusarium spp. and Rhizoctonia spp.) control in tobacco fields and to investigate whether Trichoderma modulates the hormone signalling network in the host to induce nematode resistance. Trichoderma harzianum (T77) was applied as a seed-treatment to the relay sunhemp crop, then tobacco was transplanted and evaluated in the field over three successive seasons. The experimental design was factorial replicated three times using an RKN-susceptible and RKN-resistant tobacco variety in microplots with high RKN populations of at least 50 RKNs per 200 g of soil. RKN population assays, disease and end-of-season root galling assessments were done. The results showed that tobacco seed-treated with T77 had markedly lower soreshin damage than those from disease control plots with merit noted when T77 was applied at transplanting. Additionally, susceptible tobacco plants grown in plots initially planted with sunhemp seed-treated with T77 had markedly lower galling (< 3 on a scale of 0-8) than plants from the disease controls. This observation was even more apparent in plots planted with resistant tobacco, which had root damage scores of 1 or less on a scale of 0-8. Used in combination with resistant varieties and recommended cultural control practices, T77 provides a promising sustainable control option for RKNs on tobacco lands in Zimbabwe.