Common bean is a legume grown globally especially in developing countries including Cameroon for human consumption. In Cameroon it is grown in a wide variety of agro ecological zones in quantities enough to last through the off growing season after harvest. Stored common bean after harvest in Cameroon are prone to fungal spoilage which contributes to post harvest losses. This study aimed at characterising storage fungi on cultivars of stored common bean using morphological and molecular techniques. Fungi were isolated from six stored cultivars of common bean; Kidney bean, Black bean, Navy bean, Pinto bean, Pea bean and Large seeded bean plated on potato dextrose agar media. Cultural, micro-morphological and molecular techniques were used to characterise the isolates. A total of four fungi isolates resulted. Homology matches of the gene sequences in the Genbank databases identified the isolates to be; Xylaria hypoxylon, Aspergillus flavus, Penicillium aethiopicum and Fusarium oxysporium. Phylogenetic analysis and multiple sequence alignment showed these isolates were of distinct species. The species of fungi recovered from the stored cultivars signified poor preservation methods carried out after harvest. Effective management and control of these fungal species in common bean at storage will help reduce post-harvest losses and increase seed health.

Potato (Solanum tuberosum L.) production in Kenya is limited by soil borne diseases especially soft rot bacteria caused by Erwinia carotovora. Although the use of synthetic pesticides has significantly contributed in the management of E. carotovora, their use is often associated with environmental pollution and loss of beneficial soil biodiversity. Here, we investigated the efficacy of neem (Azadirachta indica M.), garlic (Allium sativum M.) and aloe (Aloe secundiflora Engl.) extracts, on the development of soft rot bacteria in three potato varieties; Kenya Mpya, Sherekea and Purple Gold. The treatments were laid out in a completely randomized design with five replicates. Interestingly, all the extracts significantly (p˂0.05) reduced the extent of rot on the treated compared to the untreated tubers. Garlic recorded the highest antimicrobial effect as seen from the extent of rot (6.50±0.59%), while aloe (29.00±1.54%) gave the least antimicrobial effect. Sherekea potato variety showed the highest tolerance to E. carotovora among the studied potato varieties. These results demonstrate potential use of plant extracts in the future development of low cost and environmental friendly biopesticides; a key step towards achieving sustainable global food production.

Tomato post-harvest pathogens are a threat to the harvested tomatoes. Tomato fruit attract more micro-organisms because of it being succulent, highly rich in nutrients and sugars that are medium for microbial growth. The pathogens destroy tomato fruits reducing the quantity of consumable fruits and at the same time lowering the profit made from the sales of the tomato fruits. Consumption of contaminated fruits results to food poisoning. Isolation and identification of pathogens causing tomato fruit rot is necessary in order to create awareness and reduce the risks of infections arising from handling and consumption of contaminated tomato fruits. The objective of this study was to isolate and identify pathogens that cause tomato fruit rots in Mwea Kenya and test the susceptibility of tomato cultivars to the rots. In this study infected tomato samples were collected from farms and markets in Mwea. Disease causing micro-organisms that were suspected to cause the post-harvest damage were isolated, identified and re-inoculated to wounded surface sterilized fresh harvested ripe tomato fruits to establish pathogenicity. Two common tomato cultivars (Kilele F1 and Roma V.F) grown in Mwea were tested for susceptibility to the common post-harvest tomato pathogens in the area. Data was analysed using SPSS frequency, percent and chi-square test statistics. Six pathogens were isolated from infected tomato samples and they varied significantly (p<0.001) with Furasium spp. being the most prevalent (30%). Damage caused by the pathogens on tomato fruits also varied significantly (p<0.001) with Rhizopus spp. causing (100%) rot. The susceptibility of the tomato cultivars to the test pathogens differed significantly (p<0.045) with Kilele F1 being the most susceptible. These findings will be of importance in making the farmers and consumers aware of pathogens causing tomato rots and cultivars that are susceptible to rots.

Rose is the world’s most traded cut flowers with 74 % being produced in Kenya. Pests like spider mites, caterpillar, aphids, thrips, nematodes and diseases such as crown gall, downy mildew, powdery mildew and botrytis highly compromise rose production. Crown gall disease caused by Agrobacterium tumefaciens is the most problematic disease of roses in Kenya, causing a production loss of up to 60 % depending on the age and variety of rose. An experiment to determine the antibacterial effect of Artemisia and ginger extracts was carried out in vitro, where the inhibitory zones around filter discs soaked with extracts on Muller Hinton agar was established. The extracts were emulsified with dimethylsulfoxide (50 %) and minimum inhibitory concentrations of Artemisia (125 mg/ml), ginger (62.5 mg/ml) and mixture of Artemisia and ginger (31.25 mg/ml) were used to soak the filter discs whereas the commercial recommended rate of copper hydroxide of 6.25 mg/ml was used. Artemisia and copper hydroxide (commercial antibiotic) had highest inhibition zone of 12.80 mm compared to ginger 10.60 mm. A mixture of Artemisia and Ginger had a slightly lower inhibition zone (10.20 mm) though not significantly different from ginger (P> 0.001). An eight-month greenhouse experiment was also done to determine the efficacy of the extracts on inoculated rose plants. The results showed that crown gall incidence and gall weight were low but not significantly different from copper hydroxide and Artemisia. Crop vigor, which was indicated by stem length was highest for Artemisia treatment with an average of 73.54 cm followed by copper hydroxide (67.25 cm) while ginger and mixture of ginger and Artemisia had 53.44 cm and 64.70 cm respectively. From the results of this research, Artemisia and Ginger extracts are promising alternative to control crown gall and possibly other diseases in field crops. Artemisia performance compares well with copper hydroxide and therefore the best alternative to replace copper hydroxide.