This study investigated the inheritance of resistance to Fusarium oxysporum f.sp. tracheiphilum (Fot) in cowpea lines. Resistant and susceptible cowpea lines were crossed to develop F1, F2 and backcross populations. Reaction to Fot was evaluated in 2015 and 2016 using seed soak and modified root‐dip inoculation methods. The expression of resistance reaction in the F1 and segregation in F2 generations indicated the role of dominant gene controlling Fot in cowpea. These results were further supported by the result of backcross (BC1P1F1 and BC1P2F1) progeny tests. The backcross of F1 with the resistant parent produced progeny that were uniformly resistant, whereas backcross of F1 with the susceptible parent produced progeny that segregated into 1:1 ratio. The F2 segregation ratio in the reciprocal cross showed no evidence of maternal effect in the inheritance of the resistance. Allelism test suggests that the gene for resistance in TVu 134 was the same in TVu 410 and TVu 109‐1. We also identified an SSR marker, C13‐16, that cosegregated with the gene conferring resistance to Fot in cowpea.

A field survey was conducted in Gboko and Ohimini Local Government Areas of Benue State where pepper is extensively cultivated to investigate the seed borne diseases of two Chilli pepper (Capsicum frutescens) types namely: 'Sombo' and Birdeye. Naturally infected pepper seeds were extracted from pepper fruits collected from farmers' fields between August and October, 2011 from the two Local Government Areas (LGAs). Using agar plate method a total of 20 genera and 36 species from three classes of fungi were isolated and identified from 800 seed samples of pepper. Colletothrichum capsici, Aspergillus niger and A. flavus were the most frequently isolated fungi with 54.75%, 44.00% and 29.75 % occurrence respectively. C. capsici/A.niger interaction had the highest occurrence of 3% followed by A.flavus/A. niger interaction with 1.25%. Nematode/fungi association had 26.25% occurrence on pepper seeds. Phoma spp, Humicola fuscoatra, Humicola dimorphospora, Bispora betulina, Phomopsis spp,Botryotrichum piluferum,Periconia byssoides,Coniothyrium fuckelii, Fumago spp, Septonema chaetospira and Syncephalotrichum racemosum are being reported on pepper seeds for the first time in Benue State. Detection of the seed borne fungi is important in the management of pepper diseases and can be a useful guide to strategic disease control.

The experiment was conducted mainly to investigate the effect of change in sowing dates on disease severity of Roselle (Hibiscus sabdariffa L) leaf spot caused by Coniella musaiensis Var hibisci, plant height, number of branches, number of fruits and calyx yield of Roselle (H. sabdariffa L). Five dates were selected with an interval of fourteen days (14) between the dates for two years (2003 and 2004) to determine the most appropriate time to sow the crop using two Roselle accessions; green (Acc 1 ) and red (Acc 3 ). The first date was determined by the establishment of the rains in the season. It was observed that change in sowing dates had significant (p = 0.05) effect on disease severity but not on plant height, number of branches, number of fruits and calyx yield. Plants sown on July 18/27 had lowest disease indices; and are thus the best and therefore recommended for cropping of Roselle.

In vitro antagonistic study using dual culture technique was carried out at Advanced Plant Pathology Laboratory, Federal University of Agriculture, Makurdi, Nigeria to assess the potential capability of Trichoderma harzianum as a biocontrol agent against Aspergillus niger isolated from rotten yam tubers. The test antagonist (T. harzianum) was introduced at three different times (same time with pathogen, two days before the inoculation of the pathogen and two days after the inoculation of the pathogen). The plates were incubated for 192 hours and measurements of mycelial radial growths were recorded at intervals of 24 hours beginning from the third day. The results of in vitro interactions between T. harzianum and A. niger revealed that T. harzianum was able to significantly (P ≤ 0.05) inhibit the growth of A. niger at the three different times of introduction of T. harzianum and this increased with the time of incubation. T. harzianum grew faster than A. niger and produced inhibition zones which completely stopped the growth of A. niger. Mean percentage growth inhibition was found to be highest (77.79%) when T. harzianum was introduced 2 days before inoculation of A. niger followed by  introduction of T. harzianum same with A. niger (45.96%). The least percentage growth inhibition (28.47%) was recorded when T. harzianum was introduced 2 days after inoculation of A. niger. In all cases, T. harzianum was observed to be effective at checking the growth of A. niger in vitro and therefore showed the capability for the biological control of the pathogen. It is therefore recommended that for effective in-vitro control of A. niger, T. harzianum should be introduced 2 days before the arrival of A. niger.