The African Phytosanitary Journal provides information on issues affecting plant health both locally and internationally. It provides a platform for the industry, research institutions, institutions of higher learning and the National Plant Protection Organizations (NPPOs) to present their findings on research on phytosanitary issues.
Honeybee propolis protects stored maize grain from damage by maize weevil (Sitophilus zeamais Motsch.) and reduces damage by larger grain borer (Prostephanus truncatus Horn) in Kenya
The losses caused by larger grain borer (Prostephanus truncatus Horn) and maize weevil (Sitophilus zeamais Motsch.) on stored maize (Zea mays L.) grains range from 9 - 45% and 12 - 20%, respectively, depending on the storage period. These are additional losses to the field losses before harvest, threatening food security status in Kenya. With maize being a staple food consumed daily, using synthetic chemical products to manage these pests has not been easy to implement. Unaffordability of these products also forces resource-poor farmers to sell their produce early at low prices, thus compromising their food security needs. This study examined the effects of honeybee propolis extract in reducing larger grain borer (LGB) and maize weevil (MW) infestation to below economic injury level. The treatments included control, 20% propolis extract, undiluted propolis extract, Actellic super® dust, Kensil F® dust, and 20% propolis extract + Kensil F® dust. Each treatment was applied to 10g of grains, and later, 30 individuals of each insect species were introduced independently. Mortality was measured after 14 days, and all insect individuals were discarded immediately. Progeny emergence was recorded after a further 42 days. Results showed 20% propolis extract caused 48% mortality of LGB but in combination with Kensil F® dust, the extract caused 67% mortality. In contrast, this concentration caused 100% MW mortality. Progeny emergence reduction of 16% - 26% for LGB and 100% for MW was observed in grains treated with propolis extract compared to untreated grains. Keywords: Propolis ethanolic extract, stored maize, postharvest loss, Prostephanus truncatus, Sitophilus zeamais
Copyright (c) 2025 African Phytosanitary Journal
Effectiveness of native entomopathogenic fungi against fall armyworm (Spodoptera frugiperda J.E Smith) in Kenya
The fall armyworm (FAW) Spodoptera frugiperda (J.E Smith) is an important pest of some of the major crops grown around the world. Its control is mainly by use of insecticides which with frequent use pose risks to human health and the environment. The objective of this study was to determine the potential of using entomopathogenic fungi (EPF) as a biological control for this pest. A laboratory experiment was carried out at Kenya Agricultural and Livestock Research Organization (KALRO)-National Sericulture Research Centre (NSRC), Thika where field-collected entomopathogenic fungi (EPF) were tested for their efficacy against FAW. A fungal suspension was made from fall armyworm cadavers collected from different parts of the country in 2018 and used to infect healthy FAW. The results showed that native fungal isolates could cause mortality of the fall armyworm caterpillars. The mortality of the fall armyworm caterpillar started five days after treatment. The cadavers were covered with white mycelia resulting in a characteristic white muscardine appearance and causing 69% mortality. The results reveal presence of native entomopathogenic fungus in the country, which can be exploited for development of an effective bio-control agent for the management of the fall armyworm. Keywords: Spodoptera frugiperda, entomopathogenic, bio-control, silkworm, mortality, mycelium
Odimo Hellen, , Nyaanga Jane, Murerwa Patrick, Guantai Mary, Kinyua Zachary Kambo Caesar, and Kasina Muo*
Development of Trissolcus basalis (Woll.) egg parasitoid bulking protocol for management of macadamia stink bug Bathycoelia distincta (Dist.)
An upsurge of macadamia stink bug (Bathycoelia distincta Distant) in Kenya has resulted in severe damage to macadamia nuts. Its management is best achieved through use of egg parasitoid, Trissolcus basalis, commonly used across the globe. To manage the pest, this study was carried out to determine rearing potential of the parasitoid, for long term bulking and field releases. It was carried out in the lab using fresh eggs of Nezara viridula, a stink bug that is easier to rear, to provide alternative rearing media. Eggs were exposed to target parasitoid for parasitization. About 143 freshly laid N. viridula egg masses were collected from the laboratory-reared colonies. Each egg batch contained 44 to 135 eggs per egg mass. The results show that 59.7% were fully parasitized, 24.8% egg masses had over 50% parasitism while the remaining 15.5% egg masses recorded less than 50% parasitism. The findings also show that the discovery efficiency of the parasitoid was not influenced by egg mass size (F=2.34, df=2, p> 0.05). Further, it was noted that parasitism efficiency decreased significantly as number of host eggs per egg mass increased (F=3.23, df=2, p< 0.05). This study confirmed that it is possible to mass produce the egg parasitoid, Trissolcus basalis, for long term sustainable management of macadamia stink bug pest in Kenya. Further, it is recommended that the parasitoid be mass produced for classical biological control of the pest to reduce loss of the crop and enhance the country’s access to global market as a result of producing quality nuts. Keywords: Parasitism, search efficiency, Nezara viridula, Bathycoelia distincta, Trissolcus basalis
Alosa N. A. Oduor, *, Dora Kilalo, Mary M. Guantai John H. Nderitu, Florence M. Olubayo and Muo Kasina*
Assessing macadamia value chain gaps in Kenya: A case of Murang’a, Embu and Bungoma Counties
Macadamia (Macadamia spp.) is an important high value cash crop in Kenya. This study sought to understand the existing gaps in the macadamia value chain in Kenya with a view of informing policy on how to enhance the value chain performance. The study was carried out in Murang’a, Embu, and Bungoma counties representing macadamia growing areas in Kenya. Data was collected from different value chain actors using a semi-structured questionnaire on various aspects of the value chain. The results show that macadamia crop is grown by both men and women farmers. The crop is becoming popular and has overtaken coffee in Murang’a and Embu Counties and maize in Bungoma County as a cash crop or source of household income. Farmers mainly plant macadamia as an intercrop (76.2%) with fruit trees, coffee, tea, bananas and miraa among other tree crops. Most farmers (65.5%) have planted grafted macadamia. Seedlings are sourced from KALRO, macadamia buying/processing company nurseries, roadside nurseries and individual farmer nurseries. Farmers’ reported yields of 67-179 kg per tree/year with Murang’a having the highest average yield of 82 kg/tree per year. Farmers sell mainly to brokers (middlemen) but they are also selling to macadamia buying or processing companies within or outside the counties. Farmers reported being exploited by the brokers and companies who were the main decision makers on the price setting of the nuts. Most farmers (72%) were aware of the opening dates for harvesting of macadamia nuts but this was not keenly being followed. The key challenges to macadamia crop included theft of the nuts, non-involvement of farmers in setting of the nuts prices, poor market prices, lack of policy guidelines on the production and marketing systems, unstructured and unregulated markets and marketing systems. These challenges if managed are expected to enhance the value chain performance, which will improve livelihood of the actors. It is therefore recommended that stakeholders should work together to resolve the identified challenges for the benefit of the value chain. A market-based solution that can resolve the identified challenges is encouraged. Keywords: Macadamia, varieties, seed type, seedling, yields, marketing, challenges, information
Kasina*, M., Gathaara, V. N., Guantai, M., Nderitu, J. H., Koima, J., Gatambia, E., Nyaga, P., Gitonga, H., Thuranira, E. G., & Kambo, C.
A survey of cultivated and wild host plants for the invasive fall army worm (Spodoptera frugiperda) in Kenya
The fall army worm (FAW), Spodoptera frugiperda (J.E.Smith) invaded Kenya in 2017 and is known globally as polyphagous pest. This pest invaded and immediately spread in many regions including Western, Rift valley, Central and Eastern Kenya and has become an important economic pest, posing serious food security threat across the country. This study was carried out to determine the range of host plants (both cultivated crops and wild plants) of FAW and to confirm its occurrence in various regions of the country. The survey was conducted in 13 counties, located between 34o and 37o east longitude and latitude 0o42’N and 03o24’S and altitude range of 905-2500m a.s.l in February and March 2018. The fall army worm was observed on 18 plant species representing Poaceae and Cyperacea plant families. The frequency of occurrence of fall army worms was 45.8% for maize (Zea mays L.) followed by napier grass (Pennisteum purpurea) (9.7%) and crabgrass (Digitaria spp) (8.0%), sorghum (Sorghum bicolor) (7.8%), Masai love grass (Seteria verticillate) (4.8%) and sudan grass (Sorghum halapense) (3.2%). Barn yard grass (Echinocloa colona), Bermuda grass (Cynodon dactylon) and sedge grass (Cyperus rotunda) each had 2.4% of FAW leaf damage symptoms. The frequency of occurrence of fall army worm on wild finger millet (Eleusine indica) and cultivated millet (Eleusine coracana) was (2.3%). Fall army worm infestation was high for maize (1.9) followed by crabgrass (1.3) and masai love grass (0.1) compared with the other host plants. The proportion of egg masses (0.2) and number of caterpillars on plants (1 .6) was higher in Maize. More caterpillars were recorded on napier grass (0.4) and crab grass (0.3). The egg masses (0.3 and 0.3) and the numbers of caterpillars (2.2 and 1.6) on maize crop was more in the vegetative V7 and V9 growth stages respectively. Fall army worm infestation was highest in Meru (2.2), Machakos, (1.9), Makueni, Taita and Tharaka Nithi (1.8) and lowest in Narok (1.2), Trans-Nzoia (1.0) and Baringo counties. Mean egg masses was highest in Makueni (0.8), followed by Machakos, Nakuru and Taita ( 0.4) and was lowest in Tharaka-Nithi, Kakamega and Trans-Nzoia counties. The number of caterpillars in the host plants was highest in Kirinyaga (3.1) followed by Meru (2.3) and Machakos (2.1) counties and lowest in Nakuru (0.0) County. 76% of the farms surveyed used insecticide to control fall army worm, except in one farm in Nakuru where pheromone traps were used to manage the pest. Mean fall army worm infestation score (1.5), number of egg masses (0.1) and number of caterpillars (1.4) was higher on cultivated crops and grass weeds growing under irrigated farms compared to those under rain-fed farming systems in the surveyed areas. Different types of insecticides were used across the counties that included; escort, cyclone duduthrin, profen, pentagon, coragen, actra, ranger and bestox. The study provides important understanding of pest distribution and potential host plants that should be taken into consideration when developing integrated pest management strategies. Keywords: Fall army worm, Spodoptera frugiperda, host plants, farming systems, infestation, IPM, Kenya
Muo Kasina, John Ogecha, Ceasar Kambo, Mary Mwari, Eliud Gatambia, Jane Koima, Matolo Nyamai, Hottensiah Mwangi, Joseph Mulwa, Boniface Ita and Zachary Kinyua
Effect of climate change on the quality of Citrus fruit produced in South Africa
Climate change is an observed reality with a significant impact globally. South Africa is not immune to this phenomenon. Like the rest of the world, South Africa experiences rise in mean air temperature and changes in rainfall trends. Since plant systems are influenced by weather, it is expected that climate change will have an effect on the production and quality of fruit. The objective of this study was to determine the impact of climate change on the quality of citrus fruit produced in South Africa. In conducting the study, historical fruit quality data was collected from packhouses in the Eastern and Western Cape provinces of South Africa over a period of 12 and 8 years respectively. Trend analysis was done on the data to determine whether there is a trend that can be observed over the period of data collection. The total soluble solids of fruit showed a marginal increase over the period of observation. Titratable acidity showed a marginal decrease. The incidence of sunburn on fruit seemed to increase over time. Other disorders like decay, creasing and oleocellosis did not show a definite trend of increasing or decreasing over time. Rind disorders seemed to decrease during the period of observation. This report discusses how the observed trends were influenced by changes in rainfall and temperature over the period of observation. It is then concluded that in this case study, the impact of climate change was not very profound and it had both negative and positive effects. The current results point towards a bleak future for citrus producers. To remain profitable, it may be necessary for producers to invest in climate change adaptation technologies. Key words: Climate change, citrus fruit, fruit quality, oleocellosis, titratable acidity
Ngcebo Parton Khumalo* Wandile Ngcamphalala
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Integrated Pest Management Decision Support System (IPM-DSS) a tool to support management of tree diseases in Kenya
Tree diseases have been noted as one of the major causes of abnormalities and malformations on perennial plants. Tree disease research in Kenya has resulted in a list of diseases identified to cause significant losses on forest plantations. The need for management of such diseases have been on the increase. The Decision Support System (DSS) was envisioned to help stakeholders make decisions to manage tree diseases on farm and in tree plantations. Information was collected across Kenya on diseases affecting seed, seedlings, plantations, natural forests and post-harvest products in sawmills. The data was entered into excel sheets and organized for database administration on MySQL software. Over 20 major fungal species were identified and their biology, distribution and management determined. This information was further fed into a query system to allow different groups of stakeholders to access the information for diagnosis and control of tree diseases. Results showed that major tree diseases in Kenya were caused by fungi belonging to the families; Botryosphaeriaceae, Nectriaceae, and Amphisphaeriaceae. The data and information availed through this query system is being used in trend analysis for proactive control and management of tree diseases in Kenya. It will also be used for farmer advisory services through closest match selection of symptom appearance based on the tree species. The query system is an innovation that will also be used for Citizen Science Data Capture to aid Kenya Forestry Research Institute in detecting emerging diseases in real-time for phytosanitary measures. The identification of commonly occurring pathogens in commercial forestry species in the country has led to research towards their control and tree improvement for resistance to tree diseases. Future plantation establishment should be based on resistant species and high-quality germplasm for maximum survival and improved yields. Key words: Advisory services, Botryosphaeriaceae, citizen science, Decision Support System, Integrated Pest Management, tree diseases.
Rice husk biochar for carbon sequestration, soil fertility and plant health improvement: A review
Carbon dioxide (CO2) is considered one of the ozone layer gases that contribute to climate change. As the area under agricultural use expands, the level of CO2 from soil as an agricultural by-product increases in the atmosphere. Burning rice husks in open air, decomposing plant materials among other activities release CO2 directly to the atmosphere. Rice husks as a by-product of rice production in Kenya has both the potential to be a source of greenhouse gas (GHG) and production of biochar. Production and deposition of rice husk biochar (RHB) into soil is thought to be one of the viable options for permanent carbon storage with related benefits to soil fertility. This review seeks to consolidate information from various studies that highlight the innovative way of using RHB in combating climate change, improving soil fertility, plant health and crop yields. Studies that have demonstrated beneficial use of RHB were evaluated to prepare this review. When RHB is used as a soil amendment, it has the ability to increase soil carbon storage, mitigate 10% of the current anthropogenic carbon emissions, improve pH and raise Cation Exchange Capacity (CEC), increase available plant nutrients, enhance inherent plant immunity, increase crop yields and improve water quality by increasing retention of nutrients and agrochemicals for plant utilization. A review of the benefits of RHB use in agriculture and climate change mitigation will enhance its adoption. The review further emphasizes the usefulness of pyrolysis in turning organic waste into bioenergy, compost and other beneficial products while protecting the environment. Key Words: Carbon dioxide, climate change, global warming, innovation, ozone layer, temperature.
Wachira Ephraim*, Nthakanio Njiru Paul, Yegon Rebbeca
Prospecting for fine scale establishment of exotic stem borer pupal parasitoid (Xanthopimpla stemmator Thunberg) in Kenya
Lepidopteran stem borers are an important constraint to cereal production in Sub- Saharan Africa. The exotic Chilo partellus (Swinhoe) is one of the most economically important stem borer pest causing extensive losses on cereal crops in Kenya. This pest has also displaced indigenous species of stem borers while expanding its range in warm, mid and high altitude areas. In order to exert control on various developmental stages of this pest, both Cotesia flavipes Cameron (larval endoparasitoid) and Xanthopimpla stemmator Thunberg (pupal endoparasitoid) were imported and released in 2002 in the Eastern region of Kenya. This study was conducted to assess the establishment status, spread and impact of X. stemmator on C. partellus following its release in Kenya. Stem borer sampling was done on farms where the biocontrol agents had been released and on transects radiating outwards from them every 15km to assess spread. A total of 100 maize plants were inspected for stem borer infestation and destructive sampling done on 10 maize stems per farm to collect immature stem borer stages. Emerging parasitoids and adult moths were identified, counted and recorded. Results of this study showed that C. partellus was the most dominant stem borer species (constituted 71.2%) followed by Sesemia calamistis and Busseola fusca (26.0 and 2.8% respectively). A decrease in overall stem borer infestation (22.47±7.42%) with no significant difference across distances from parasitoid release points (F=0.4; df=3, 51; p>0.05) was also recorded. Seven parasitoid species were recovered, the most abundant being C. flavipes and this coupled with a significant increase in parasitism (25.27±3.27%) (V=1213, p˂0.05) from pre-release levels. The parasitoid of interest, X. stemmator was not recovered. This suggests a failure to establish though there is need to sample alternative hosts before this is declared. Key words: Classical biological control, lepidoptera, pupal parasitoid, post release survey, Xanthopimpla stemmator, Eastern Kenya
Esther Abonyo*, George Ongámo, Catherine Lukhoba, Gideon Nyamasyo, Gerphas Ogola, G, Hippolyte Affognon, H, and Bruno Le Ru
Occurrence and distribution of Papaya Mealybug (Paracoccus marginatus Williams and Granara de Willink) (Hemiptera: Pseudococcidae) in the coastal area of Kenya
Papaya mealybug, Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae) was first reported in Kenya in 2016. Kenya Plant Health Inspectorate Service (KEPHIS) together with other collaborators has since continuously carried out surveillance and management initiatives to contain the pest. In November and December 2020, a delimiting survey of the papaya mealybug (PMB) was conducted in six coastal counties. The survey was aimed at determining the incidence and intensity of infestations in the farms, host range in the region and to assess the farmers’ awareness on management options. Sixty-seven (67) farms were randomly sampled across the six counties. An open data kit (ODK) mobile tool generated questionnaires were administered to collect data on PMB incidence, infestation intensity and management practices applied and their effectiveness based on responses from farmers. Papaya mealybug was confirmed to occur in the six counties surveyed with incidences which ranged from 10- 100%. The intensity of infestation in the counties varied from very low to medium based on the applied scale and was higher on fruits compared to the leaves, stems and flowers. The survey further revealed that PMB infested citrus, sugarcane, okra and custard apple that were initially not reported as hosts. Majority (65%) of the farmers interviewed were aware about the occurrence of PMB on their crops and could positively identify and describe it. Some farmers had tried to manage the pest and the lowest incidence (3%) was recorded from fields where farmers combined chemical and cultural practices for management. In order to contain the impact and spread PMB, authorities and research institutions in Kenya may need to consider deploying classical biological control management which has successfully been deployed in other countries. Key words: Delimiting survey, incidence, infestation intensity, Kenya, papaya mealybug.
Ombuya Alfayo*, Kosiom Thomas, Marangu Jason, Kemei Festus, Mbae Caroline and Macharia Isaac
Prospects of indigenous fungi as novel biological control agents of thrips (Frankliniella occidentalis Pergande, 1895) on tomato (Solanum lycopersicum L.) in vivo
Tomato (Solanum lycopersicum L.) is an important horticultural crop in Kenya. Its production is constrained by many factors, among them arthropod pests and diseases. In response, farmers rely on synthetic pesticides, which lead to contamination of the produce, pest resistance and pollution of the environment hence there is need to identify safer, affordable alternatives. Biological control is considered safe, self-sustaining and cost effective. This study was aimed at determining the effectiveness of indigenous fungi in managing Western flower thrips Frankliniella occidentalis on tomato. Efficacy trials were conducted in farmer’s fields in Bungoma County, Kenya between March and November 2018. Treatments included fungal isolates Trichoderma harzianum, Gliocladium virens, Verticillium spp., Paeciliomyces victoriae and Fusarium oxysporum selected after in vitro screening. These were compared to commercial fungus Beauveria basssiana, a synthetic pesticide imidacloprid and untreated control. Treatments were replicated four times, arranged in a randomized complete block design. Data collected on population of thrips and the yield of tomatoes were subjected to Analysis of Variance (ANOVA). Means were separated using Student Newman-Keuls (SNK) test at p≤0.05. In the first season at Bukonoi, F. oxysporum significantly (p<0.05) recorded the least (38.1) mean number of thrips compared to the untreated control (89.2). At Cheptais, F. oxysporum and T. harzianum treated plots significantly (p<0.05) recorded the least mean number of thrips of 48.1 and 20.5 in the first and second season, respectively. Higher yields of 4.9 t ha-1 and 29.5 t ha-1 were obtained from plots treated with T. harzianum in the first and second season, respectively. The findings of this study demonstrated that F. oxysporum and T. harzianum have the potential to be developed as fungal biopesticides for management of thrips on tomato crop. However, large scale field trials are warranted to validate the effectiveness of these fungal isolates. Key words: Biopesticides, Frankliniella occidentalis, Fusarium oxysporum, Solanum lycopersicum, Trichoderma harzianum.
Michael Wabukala Barasa*, Ruth Kahuthia-Gathu, Maina Mwangi and Waceke Wanjohi
Atoxigenic Aspergillus flavus (Aflasafe KE01) application reduces Fumonisin contamination in maize in lower Eastern Kenya
Management of fumonisin contamination in maize has been a challenge largely because there are no effective management measures for Fusarium ear rots. Maize varieties that are resistant to fumonisin contamination are also lacking. This study was conducted to determine the efficacy of atoxigenic Aspergillus flavus (Aflasafe KE01) on fumonisin contamination of maize. The study was carried out in four sub-counties in lower Eastern Kenya. Twenty-four maize fields were selected in each sub-county; where 12 fields were treated with Aflasafe KE01, while 12 fields comprised the untreated controls. Aflasafe KE01 was applied at a rate of 5 kg/ha and 10kg/ha by hand broadcasting in maize fields two to three weeks before tasselling of maize. Fumonisin level in the maize samples was determined using Accuscan Pro-reader enzyme-linked immunosorbent assay (ELISA). The results showed that application of Aflasafe KE01 reduced fumonisin in the maize from the Aflasafe KE01 treated fields by up to 68% compared to samples from untreated fields. About 62.5% of the maize fields treated with 5kg/ha of Aflasafe KE01 met the European Commission regulatory threshold of ≤2ppm for total fumonisin as compared to about 45% from the control fields. This indicates that Aflasafe KE01 is a potential biopesticide for the management of fumonisin in maize. Therefore, efficacy of Aflasafe KE01 to reduce fumonisin contamination of other key staples in Kenya should also be evaluated. Key words: Aflasafe KE01, atoxigenic Aspergillus sp., fumonisins, maize.
Ndirangu Esther Wanjiru*, Muthomi James, Wagacha John Maina, Mutegi Charity
Farmer perception, knowledge and management of the scale insect pest complex infesting crops and trees in Coastal Kenya
Scale insects and mealybugs (Hemiptera: Sternorrhyncha: Coccomorpha) are serious plant sap-sucking pests affecting a wide range of cultivated crops and tree species. The insects are highly diverse and can have devastating effects on yields due to lack of farmer awareness and inappropriate management practices. Recent alien mealybug invasions in Kenya include among others, papaya mealybug (Paracoccus marginatus), a highly invasive pest that is spreading quickly. Farmer experience with diverse crop pests can support development of a successful pest management strategy and contribute to reduced impacts on both crop yields and agro-biodiversity. This socio-economic survey was carried out in three coastal counties of Kenya (Mombasa, Kilifi and Kwale) to establish the impact of scale insect and mealybug pests on farmer livelihoods and to document the perception, knowledge and management practices used by smallholder farmers. Data from oral interviews using ODK were administered to respondents and analysed using Excel and GENSTAT. It emerged that 26% of the respondents were familiar with scale insects and 51% with mealybugs, respectively. Of these, 78.13 % and 94% acknowledged having encountered scale insects and mealybugs, respectively, on their farms. The farmers confirmed that scale insect pests affected a high diversity of crops and trees. About 56% of the respondents used pesticides to control the pests while 25% did not apply any management strategy. The remaining 19% practiced cultural control methods such as field sanitation and intercropping with less susceptible crops. Pesticides were reported to be moderately effective (41-70%) at controlling scale insects and mealybugs. Other management options reported by farmers included farm hygiene, the use of high-pressure water jets, and applications of ash and bio-pesticides such as home-made neem extract. Based on the findings, it is recommended that capacity building for farmers and input providers be undertaken to enhance the knowledge of scale insect and mealybug pest biology, symptoms of crop and tree attack, host ranges and management practices. Additonally, training on the use of low-risk pest control products and innovative control methods should be undertaken to reduce the impact of the pest on crop production and agro-biodiversity. Keywords: Farmer knowledge, management, mealybugs, scale insects and socio-economic survey.
Impacts of selected Climate Smart Agricultural Practices on African Indigenous Vegetables in Kenyan drylands
Climate change has had significant impacts on the cultivation of African Indigenous Vegetables (AIVs) resulting in insufficient yields and food insecurity. African indigenous vegetables are important food crops used in combating malnutrition and food insecurity. The AIVs have the potential to provide nutrition and sustain smallholder farmers’ livelihoods. However, little is known about the impacts of Climate-Smart Agriculture Practices (CSAPs) on the yield levels in AIVs. This study was therefore conducted to evaluate the impacts of selected CSAPs on the yield levels in cowpeas (Vigna unguiculata. L) and black nightshade (Solanum nigrum. L) in Kenyan drylands. Six treatments consisting of organic manure, commercial organic fertilizers, irrigation, mulching, inorganic fertilizers and controls were used. Research plots measuring 3m by 3m were set out in a randomized complete block design and sowed with certified cowpeas seeds and well-established black nightshade seedlings. Treatments were applied at land preparation and at 7 days after crop germination. Data was collected on plant height at vegetative stage and the overall primary yield at crop maturity. Analysis of variance (ANOVA) was conducted on the quantitative data collected and analyzed using Genstat software. Post hoc analysis was carried out for significant means using Tukey’s Honest Significant Difference (HSD) test at p≤0.05. The results revealed significant differences in both the plant height and primary yield across all treatments (p≤0.05). The AIV yield levels were significantly influenced by the CSAPs products used. Plots treated with organic manure, mulching and commercial organic fertilizers had significantly higher yields. Control plots had the least amount of yields. Key words: ANOVA, Climate change, food security, malnutrition and soil degradation.
Muthama Eric*, Dharani Najma, Namikoye Samita, Rebecca Karanja
Evaluation of pests affecting maize imported across Malawi borders
Cross-border trade is one of the major factors that puts maize at risk as it creates pathways for spread of different maize pests in Malawi. This study was carried out to identify pests associated with imported maize in order to improve phytosanitary measures and reduce the introduction of pests. Random sampling technique was used to collect imported maize at selected borders and commercial cities with the aim of identifying pests present during importation. There were no significant differences (p>0.05) in the population of insect pests before and after incubation in all the surveyed districts. Significant differences were observed after incubation for larger grain borer (LGB) and common maize weevil. The highest percentage infestation (32%) of living LGB was recorded in Karonga and the least in Mzuzu (p<0.05). On the other hand, for maize weevil, the highest percentage infestation (20%) was recorded in Nkhatabay while the least was observed in Lilongwe district (p<0.05). Common fungal pathogen species isolated included Fusarium (70%), Aspergillus (29%) and Penicillium (1%). The highest percentage of kernel infection with Fusarium sp. was recorded in Dedza and Lilongwe while for Aspergillus sp. were in Mzuzu. The Aspergillus sp. isolated were A. niger (29%), A. flavus (22%) and A. parasiticus (5%) while Fusarium sp. isolated was Fusarium verticilloides. The study provided the status and causes of storage losses by various pests on maize. It is recommended that the phytosanitary system present at various Malawi borders where maize is imported should be strengthened. This can be achieved through human and infrastructure capacity building, strict compliance with importation regulations and improved funding of organizations mandated to ensure phytosanitary compliance. Key words: Aspergillus sp., consignment, food security, grain storage, random sampling, sanitary and phytosanitary measures.
Matilda Mdyetseni*, James Wanjiku Muthomi, Donald Kachigamba
Displacement of toxigenic Fusarium species by atoxigenic Aspergillus flavus (Aflasafe KE01) application in maize fields in lower Eastern Kenya
Maize is grown in areas with environmental conditions that are ideal for growth of most cereal pathogens such as Fusarium fungi. However, there is lack of effective fungicides to control fumonisin producing Fusarium. This study was conducted to determine the efficacy of atoxigenic Aspergillus flavus (Aflasafe KE01) on the population of Fusarium species in maize fields. The study was carried out in four sub counties in lower Eastern Kenya (Kaiti, Kathiani, Nzambani and Wote). Twenty-four maize fields were selected in each sub county where 12 fields were treated with Aflasafe KE01, while 12 fields comprised the untreated controls. Aflasafe KE01 was applied by hand broadcasting in the maize fields two to three weeks before tasselling of maize. Maize grain samples were collected from each field at harvest and ground using a Bunn coffee mill grinder. Fusarium species were isolated from the ground maize using pour plate method following serial dilution on low strength potato dextrose agar (PDA)and Spezieller Nahrstoffarmer. The results showed that application of Aflasafe KE01 effectively displaced toxigenic Fusarium species in maize fields. Maize samples from Aflasafe KE01 treated maize fields recorded significantly lower incidence (41%) of the Fusarium species compared to untreated maize fields (60%) (p≤0.01). These results indicate that Aflasafe KE01 is a potential biopesticide for the biocontrol of Fusarium species in maize. Key words: Aflasafe KE01, atoxigenic Aspergillus sp, Fusarium species, maize
Reaction of potato cultivars to Potato Cyst Nematodes (Globodera rostochiensis and G. pallida) under greenhouse conditions in Kenya
Several measures have been recommended in the control of potato cyst nematodes (PCN) with resistant potato cultivars being considered as the most practical and affordable for smallholder potato farmers in Kenya. However, the level of resistance in locally grown potato varieties is yet to be established. The aim of this study was to screen Kenyan potato cultivars against PCN under greenhouse conditions. Eleven potato cultivars namely Shangi, Dutch Robijn, Sherekea, Nyota, Roseline tana, Tigoni, Unica, Asante, Chulu, Kenya Mpya and Arka were screened with Desiree (susceptible variety), Manitou (resistant cultivar) as controls. For each potato cultivar, there were two sets of plants with the first set being inoculated with 50 cysts, while the second batch was nematode-free. The treatments were arranged in a completely randomized design with three replications. A scale of 1-9, with 9 indicating the highest level of resistance was used in the assessment of disease severity. Nematode infestation caused a reduction in root mass across the 11 cultivars from 20 to 100% compared to uninoculated controls. Reproductive index of PCN viable eggs across the 11 cultivars was <1 compared to control (Desiree). Potato cultivars Shangi, Tigoni, Dutch, Chulu, Asante, Unica, Arka, Kenya Mpya, and Roseline Tana had a severity score of 1-3 (>95%), hence were considered to be susceptible to PCN. The cultivars Sherekea and Nyota had a severity score of 4-6 (<25%) and hence were considered partially resistant to PCN. The findings of this study provides a basis of integrating partially resistant potato cultivars into PCN management in smallholder farms. Keywords: Cyst viable eggs, reproductive index, resistance, susceptible, smallholder farmers, severity score.
Otieno Berrick Ochieng’ *, John Wangai Kimenju, William Maina Muiru, Lusike Wasilwa, Miriam Otipa, Moses Nyongesa
Morphological and molecular characterization of the rust fungus, Phakopsora apoda causing leaf rust on Brachiaria grass in Rwanda
Brachiaria grass is one of the major forages that plays a key role in push pull technology. Different diseases including leaf rust caused by rust fungus, Phakopsora apoda have recently become an important challenge resulting in yield loss of Brachiaria grass in different countries including Rwanda. The objective of this study was to provide morphological and molecular characteristics of Phakopsora apoda causing Brachiaria leaf rust. Spores isolated from rusted Brachiaria leaves collected in five districts of Rwanda were analyzed. Samples were put in paper bags and left at room temperature for two days. Thereafter, spores were removed using brushes and put in eppendorf tubes, stored at 4oC in darkness for further characterization. For morphological characteristics, colour and measurements of spores were recorded using Optika B-350 microscope with installed camera and calibrated micrometer. Multigene analysis using rust specific primers and large subunit (LSU) of nuclear ribosomal RNA was performed for molecular characterization. The results indicated that the colour of spores was yellowish or brownish while the shape was ellipsoidal or circular with average measurements of 25.1μm and 16.8μm for length and width respectively. Primers amplified the size of DNA between 1291bp and 1381bp and the size between 874bp to 882bp for rust specific primers and LSU respectively. The identity of the sequence was 96% with e-value of 0, sequence coverage of 60% for rust primer and the sequence identity was 94.97% to 95.37%, sequence coverage of 99% to 100% and e-value of 0 for LSU primer. All sequences recovered from five isolates of leaf rust matched to the genebank accession number MG461668.1 for both rust specific and LSU sequences. The results of this study provide useful information to develop effective options for leaf rust disease management in Rwanda. Key words: Internal transcribed spacer, large subunit, nuclear ribosomal RNA, Phakopsora apoda, sequence, spore.
Uzayisenga Bellancile*, Mutimura Mupenzi, Muthomi Wanjohi James, Mwang’ombe Wakesho Agnes
Maize Head Smut: Pathogenesis, Epidemiology, and Management Options
Maize (Zea mays) head smut caused by Sphacelotheca reiliana, a basidiomycete with worldwide distribution, can cause devastating crop losses that pose a food security threat. While Kenya has experienced high incidences of the disease in the recent years, the seed certification regulation has a zero tolerance on S. reiliana. The spores of S. reiliana remain viable in soil for many years and serve as the main inoculum source as they germinate when the conditions are favourable and infect the host in the early stages of growth after germination. After penetration, the fungus grows systemically as the plant matures eventually transforming part or all of the inflorescence (ears and tassels) tissues into smut galls. The symptoms develop because the inflorescences have increased levels of reactive oxygen species, auxin, and misregulation of floral regulatory transcription factors. The most practical control strategy for maize head smut encompasses the use of resistant/tolerant cultivars, fungicide treatment (of seed or drenching of rows immediately after seeding), and field hygiene/ sanitation. Crop rotation may help when host crops are not planted for between 2-3 years or even more. Resistance genes, including ZmWAK, found in the major quantitative trait locus qHSR1/qHS2.09 regulate resistance of maize to head smut. The objective of this review paper is to provide an understanding of the head smut disease pathogenesis, epidemiology, and effective management options.
Copyright (c) 2020 African Phytosanitary Journal
Distribution and host range of Bemisia tabaci and other whitefly species in major horticultural production areas in Kenya
Horticulture is the second most important export earner to Kenya after tea. The sector is faced with several challenges with pests and diseases being ranked as the most important. Whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is an important pest of many horticultural crops. Kenya has had several produce interceptions in international markets due to the presence of B. tabaci, which is a quarantine pest in most territories including the European Union. A survey was undertaken to determine the distribution of B. tabaci in major horticultural areas in Kenya. A total of 26 districts were visited during the survey and whitefly samples were collected from different crops. Collected samples were submitted to the plant quarantine station Muguga laboratories for analysis. Five whitefly species were identified: Bemisia tabaci (62.4%), Trialeurodes vaporariorum (25.9%), Aleurodicus species (9.8%), Aleurodicus disperses (1.6%) and Aleurocanthus woglumi (0.1%). Bemisia tabaci and T. vaporarium were observed in most plants while the rest had a limited host range. Bemisia tabaci and T. vaporariorum were collected in almost all the districts surveyed indicating that the two whitefly species are distributed in most of the horticultural production areas.
Macharia, I*., Heya, H., Momanyi, G., Avedi, E., Mweke, A., Koech A., Oronje, M
Copyright (c) 2019 African Phytosanitary Journal
Seed certification as a means of curbing emerging diseases: A case study of Maize Lethal Necrosis (MLN) in Kenya
Maize lethal necrosis (MLN) is an important constraint in maize production in sub-Sahara Africa that threatens food security and poses challenge in trade. It was first reported in Kenya in 2011 and has since spread to other countries in the region. In Kenya, the disease is caused by a combination of Sugarcane mosaic virus (SCMV) and Maize chlorotic mottle virus (MCMV), which are vectored by aphids and thrips, respectively. Maize is the main staple food in Kenya and therefore, with the advent of the MLN, there was need to establish mechanisms aimed at combating the spread of the disease. This resulted in the amendment of seed certification protocol which included testing of seed. In consultation with seed stakeholders, KEPHIS incorporated guidelines for MLN inspection in maize seed certification program where all maize seed crops should be inspected four times including preliminary, first, second and third inspections. A seed sample was taken before seed dressing for laboratory test to ensure the lot is free from MLN. Imported seeds were also tested for MLN before being accepted into the country. Furthermore, there have been concerted efforts by breeders and researchers to develop and screen maize lines for resistance to MLN. Other strategies that have been put in place include control of vectors and use of certified seed which are free from MLN. Amendments in seed certification program that were implemented in Kenya have led to drastic reduction of MLN. It is further hoped that resistant maize lines from the breeding program will further support the effort to manage the disease.
Peter Shango*, Charles Onyango , George Kariuki
First Report of Tuta absoluta (Meyrick) in Zambia
In 2014, the NPPO of Zambia, the Plant Quarantine and Phytosanitary Service (PQPS) initiated a pest risk analysis for Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), the tomato leaf miner. This was after increased reports of the pest spreading southwards in Africa and neighboring Tanzania officially reporting the pest in 2013. By 2014, the pest was reported to occur in Algeria, Egypt, Ethiopia, Libya, Morocco, Niger, Senegal, Sudan, Tunisia, Kenya and Tanzania. By end of 2015, farmers in some districts in Zambia reported pest damage and suspected that it could be T. absoluta. This posed a serious threat to the Zambian tomato industry as tomato is one of the most important vegetable crops in Zambia grown both on a small scale and commercial scale as a cash crop. It accounts for 86% of the total value of fresh fruit and vegetable sales within the smallholder sector for Zambia. For this reason, PQPS initiated a detection surveillance of the pest in reported areas in February 2016. The Zambia preliminary surveys revealed that the pest is present in Northern, Copperbelt, Lusaka and Central Provinces of Zambia. Identification of the pest was confirmed by observing collected adult moths for key taxonomic features; filiform antennae, brown or silverfish with black spots on the moth wings and moth size. Other factors for identification were characteristic damage on leaves and fruits, pheromone traps catches and consultation of international experts in Tanzania. Introduction of T. absoluta to Zambia has devastated the Zambian tomato production industry. A taskforce has been formed to address the threat being caused by T. absoluta. Zambia has also updated its phytosanitary import conditions for tomato since this confirmation and drafted the legislation to regulate movement of tomatoes. Notification for the first report has since been sent to the International Plant Protection Convention (IPPC).
Abass M.S*., Msiska, K.K, Chomba, M. D., Mudenda, M., Mukuwa, P.S.C.
Efficacy of thermotherapy combined with chemotherapy and meristem tip culture in reducing Cassava brown streak virus in infected cassava
Thermotherapy, chemotherapy and meristem tip culture have been used either alone or in combination to eliminate viruses from plants. . The objective of this study was to determine the efficacy of combining thermotherapy with meristem tip culture and chemotherapy on the reduction of CBSV from infected cassava.Cassava Brown Streak Virus infected cuttings of Guzo variety collected from Coast region of Kenya, were established and maintained in a greenhouse at the Plant Quarantine Station, Kenya Plant Health Inspectorate Service (KEPHIS) in Muguga. Cassava leaves were sampled from eighteen plants and virus indexing done using RT-PCR with virus specific primers. Those confirmed to be positive for CBSV were used as initiation materials for the prospective test plants. From the initiated tissue culture materials, the 2nd subcultures were subjected to heat treatment at 38°C for 21 days. They were later subjected to ribavirin treatment at varying concentrations of (10mg/l, 20mg/l, and 30mgl) then left to establish for 14 days. Meristems of 1mm were excised from heat treated plantlets at 38°C for 21 days and cultured in vitro in modified Murasgige and skoog media. Nodal plantlets of 10mm not subjected to any treatment were used as controls. There was a significant difference (P<0.01) in the number of plants that survived among the treatments. Thermotherapy combined with chemotherapy resulted in complete mortality of plants due to the high stress levels from the high temperatures combined with the phytotoxic effect of the ribavirin. Thermotherapy followed by excision of meristem tips (1mm) resulted in 68.8% shoot survival with 84% being virus-free. Thermotherapy combined with meristem culture was successfully employed to produce CBSV-free cassava plants.
Maureen Mwangangi*, Ivan Obare, Stephen Khisa, Elizabeth Nduta, Salome Kivuva and Jully Nyapur
Oriental Fruit fly distribution within Kandara sub county, Murang’a, Kenya
The Oriental fruit fly (Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), previously recognized as Bactrocera invadens, presence in Kenya dates since 2003, the first record of this pest in Africa. Its phytosanitary importance resulted to avocado export ban to South Africa in 2008 and later to Seychelles, to prevent possible entry of this pest into these markets through fruit trade. To regain these markets and avoid more external market loss, this study was carried out to facilitate creation of a pest free area for fruit flies as required by the International Standards for Phytosanitary Measures (ISPM) number 26. Detection survey for the pest was conducted using 110 methyl eugenol lure-based traps laced with malathion insecticide, placed throughout Kandara Sub-County, at a density of 5 traps/km2 in June 2013. The sub county has the highest concentration of small-scale farmers of avocados for export markets in Kenya. The traps were examined after 2 weeks of placement. Data on host plants was also collected. The results showed that traps captured the pest in all agroecological zones (Lower highland (LH)1, Upper midland (UM) 1, Upper midland (UM) 2 and Upper midland (UM) 3). Possible host plants observed in the farms included avocado, mango, pawpaw, guava, coffee, passion fruit, loquats, banana, citrus, and tree tomato. The pest density was highest in UM 3, which has the lowest elevation and the highest concentration of mango orchards. High trap catches recorded in market centres was associated with poor disposal of fruits. The lowest pest density was recorded at LH 1, which has the highest elevation in the sub-county. Therefore, creation of a pest free area in the Sub County will rely on effective mass trapping exercise for more than six months in order to remove all the flies, followed by protection of the area from emerging flies using strategically placed traps and various cultural practices, accompanied by strong farmer participation and stakeholder partnership to ensure integrity of exported fruit sources.
Kasina M*, Momanyi G., Mulwa J., Karanja T., Kithusi G.K., Matolo N. and Maingi P
Pest Incursions Pose a Serious Threat To Food Security and the Kenyan Economy
Although Kenya has a well-developed phytosanitary system to regulate introduction of plant and plant products, several pest incursions have been reported in the last two decades. The incursions have culminated in devastating impact on agriculture, biodiversity and the entire Kenyan economy. The objective of this review is to consolidate information on the pests involved, their distribution, estimate the economic losses associated with them and management measures in place. A total of 11 major pests and diseases namely Asian citrus psyllid (ACP), Bactrocera dorsalis, Banana xanthomonas wilt (BXW), Cassava brown streak disease (CBSD), Cassava mosaic disease (CMD), Fall army worm (FAW), Maize lethal necrosis disease (MLND), Papaya mealybug (PMB), Parthenium hysterophorus, potato cyst nematode (PCN) and tomato leaf miners (Tuta absoluta) have been reported in the last two decades. Some of the pests are persistent, invasive, vicious and fast spreading. For instance, the FAW has now spread to nearly all maize growing areas in Kenya in one year after the pest was first reported in 2017. The incursion pests are a major threat to food security, expensive to control and are a barrier to international market access. Integrated measures including improvement of diagnostic potential, increased pest and disease surveillance, improvement in rapid response and pest containment are needed in view of the dangers posed by incursion pests to the entire Kenyan economy whose mainstay is agriculture.
Macharia I., Koome F., Kosiom T., Munguti F., Mukoye B., Kimani E, Kimenju J.W.
New scale insect country records for Kenya (Hemiptera: Coccomorpha) from old samples in insect collections
Scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) are some of the least understood insects, particularly in agriculture, even though they can cause high crop losses. Due to their small size and cryptic habits they are rarely noticed at the onset of an infestation. In Kenya, efforts have been initiated to understand these pests better. Scale insects from Kenya, found in samples between 13 and 107 years old, were studied in the insect collections of the Natural History Museum, London, U.K. and the Kenya Agriculture and Livestock Research Organisation, Nairobi, Kenya. The study identified 51 new country records of scale insects including one new continental record for Africa, Ferrisia dasylirii (Cockerell) (Pseudococcidae). Of the new records, 35 species (68.6%) are native to Africa and 16 (31.4%) have been introduced from elsewhere. Six of the 51 species (11.8%) are pests in Kenya today. Amongst the introduced species, at least one (Aonidiella comperei McKenzie) could cause plant quarantine issues in trade, and four (25.0%) are pests, more than four times the frequency of pests amongst the African species (5.7%). The remaining 45 species have been present in Kenya for at least 13 years and many have not been collected again since the original samples, suggesting that either they have not survived or they are rare because they are under good natural control. Most of the introduced species listed (75.0%) have not caused economic problems in Kenya to date, so it is thought unlikely that they will do so in the future.
Watson G. W. *, Ouvrard D., Kasina M., Achieng J.C., Githae M.M., Mulwa J., Kinuthia W., Macharia I., Heya H.M, Polaszek A.
Next generation sequencing as a tool in modern pest risk analysis: a casestudy of groundnuts (Arachis hypogaea) as a potential host of new virusesin western Kenya
Groundnut (Arachis hypogaea, L.) is grown in diverse environments throughout the semi-arid and sub-tropical regions of the world. Poor yields of 500-800kg/ha are attributed to poor agronomic practices, pests and diseases. The major disease reported in Kenya is Groundnut rosette disease (GRD). But recent observations in the field showed that the crop has varied and severe symptoms in addition to those caused by GRD. This required deeper analysis to establish the causal agents. Groundnut samples with virus-like symptoms were collected from western Kenya in 2016. Total RNA was extracted using All Prep RNA Mini Kit. Five mRNA libraries were prepared using the Illumina TrueSeq stranded mRNA library Prep Kit and pooled for multiplexed sequencing using an Illumina HiSeq 2500 to generate paired end reads (FastQ Sanger). The reads were analysed in the Galaxy project platform (customized). Quality reads were first mapped onto plant genome Refseq and unmapped reads isolated and mapped onto virus Refseq using Bowtie 2 (v2.2.3). Groundnut rosette virus satellite RNA, Groundnut rosette virus, Groundnut rosette assistor virus, Ethiopian tobacco bushy top virus, Cowpea polerovirus 2, Chickpea chlorotic stunt virus, Melon aphid-borne yellow virus, Phasey bean mild yellow virus, Beet mild yellowing virus, White clover mottle virus and Cotton leafroll dwarf virus were identified in four libraries. Other viruses (with less than 100 reads) including Bean common mosaic virus, Bean common mosaic necrosis virus, Cowpea chlorotic mottle virus RNA 3, Broad bean mottle virus RNA 3, Passion fruit woodiness virus among others were also mapped. Some of the viruses common in western Kenya were confirmed by PCR. The presence of at least three viruses in groundnuts in Western Kenya highlights the importance of starting a germplasm clean-up program of the plant material used as seed in this crop.
Mukoye B1*., Mangeni B. C2., Sue J3., Mabele A. S2. and Were H. K2.
Copyright (c) 2023 African Phytosanitary Journal
Abundance and Diversity of Frugivorous Fruit Flies in Kandara, Murang’aCounty, Kenya
Fruits and vegetables are important source of livelihood to farmers and major horticulture sub sector with high contribution to agricultural GDP in Kenya. This study was conducted to determine diversity and abundance of frugivorous fruit flies in Kandara sub county, Murang’a County in 2018, at a place where first area of low pest population was created in Kenya for Bactrocera dorsalis. Three sets of pheromone traps (Methyl-Eugenol, Cuelure and Trimedlure) were set in six trap stations within farmers’ orchards in four agro-ecological zones (LH1 (Lower Highland Zone), UM1 (Upper Mid-land Zone), UM2, and UM3). The trap catch data was collected fortnightly and data analyzed. Six fruit flies species namely; Bactrocera dorsalis, Ceratitis cosyra, Ceratitis capitata, Zeugodacus cucurbitae, Dacus bivittatus and Perilampsis sp were identified. Bactrocera dorsalis population was significantly (P<.001) different across the four agro-ecologies with lowest densities at LH1 and highest at UM3. Likewise, C. capitata recorded significant (P=0.042) difference densities across the agro-ecological zones, but no significant (P=0.386) difference was recorded for C. cosyra across the agro-ecological zones. Further, there was significant (P=0.012) difference in the number of Perilampsis sp across the agro-ecologies with the highest number recorded in UM1. Both Z. cucurbitae (P=0.061) and D. bivittatus (P=0.056) had low abundance across the agro-ecologies. The peak infestation period differed across the various fruit fly species, whereby B. dorsalis peaked in May, C. capitata in February and C. cosyra in January. The study shows that abundance for the fruit flies is probably related to their preferred hostplant and the weather patterns. We recommend continuous monitoring and intensifying trapping activities during peak periods in order to control the pest and protect fruits from damage. Farmers should be trained on the use of pheromone traps to reduce over-reliance on pesticides.
Muriuki C.1,2, Guantai M.3, Samita N.1, Mulwa J.4, Nyamai M.4 and Kasina M2
The Effect of Seed Source and Post-harvest Practices on Quality of Soybean (Glycine max) Seeds in Busia County
Majority of farmers growing legumes use and recycle seeds from informal sources for the next crop. The quality of such seeds is unknown and usually leads to accumulation of pest, diseases and reduced yields. This study was carried out to determine production practices and quality of soybean seeds obtained from informal sources in Busia County. A survey was conducted to collect information on source of soybean seeds, production and post-harvest handling practices. Seed samples were collected from farmers, local market and agro-dealers. The seeds were evaluated for purity, seed coat damage, germination, vigour and fungal infection. Majority (48%) of farmers in Busia County used farm saved seeds, 29% and 23% used seeds from community based organizations and local markets, respectively. Most of the farmers (92%) used inappropriate threshing techniques like beating with sticks and about 80% of the farmers did not treat seed either before storage or during planting. Majority (68%) stored soybean for three months only. Seeds from informal sources had low purity, higher seed coat damage and infection as compared to certified seeds. The physical purity of seeds from the informal sources did not meet the recommended standard of 98% however their germination was comparable to 75% germination standard. Farmers therefore, should be advised to adopt use of certified seeds and appropriate handling techniques.
Ochran, M. K., 1 Narla, R. D., 1 Muthomi J. W1 . and Ochuodho J. O.2
Status of Maize Lethal Necrosis Disease in Zambia
Maize is a staple food in Zambia and contributes immensely to food security for smallholder farmers. Disease outbreaks such as Maize Lethal Necrosis Disease (MLND) can be a key constraint to maize production. This disease is caused by synergistic co-infection with Maize Chlorotic Mottle Virus (MCMV) and any virus from the family Potyviridae, particularly, Sugarcane Mosaic Virus (SCMV), Maize Dwarf Mosaic Virus (MDMV) or Wheat Streak Mosaic Virus (WSMV). In 2011, an outbreak of MLND affecting almost all of the currently grown commercial varieties posed a challenge to maize production in Kenya and it has since been reported in DR Congo, Ethiopia, Kenya, Rwanda, Tanzania, and Uganda causing yield losses of up to 100%. Despite MLND having been reported in some neighboring countries, there is no information on the status of the disease in Zambia. Additionally, there is a lot of grain and seed trade between Zambia and other countries among which MLND has been reported. The aim of this study was to establish: (a) the status of MCMV; (b) agricultural practices used by farmers and (c) insect vectors associated with MLND. A survey was conducted in nine (9) provinces of Zambia during 2014/2015 and 2015/ 2016 cropping seasons. Farmers’ maize fields were sampled at every five to ten-kilometer interval and tested using rapid diagnostic kits capable of detecting MCMV. Four hundred and nineteen samples collected all tested negative for MCMV. Zambian Agricultural Research Institute (ZARI), with all stakeholders in the maize value chain should continue implementing measures aimed at preventing the introduction of MLND in Zambia.
Chomba, M. D*., Msiska, K. K., Abass M. S., Mudenda, M., Mukuwa, P.S.C.