Prevalence, detection and characterization of tomato spotted wilt and iris yellow spot tospoviruses occuring in Zimbabwe.

Doctor of Philosophy in Plant Pathology. University of KwaZulu-Natal,Pietermaritzburg 2017.Abstract available in PDF file

Tagetes Minuta Formulation Effect Sitophilus Zeamais (Weevils) Control in Stored Maize Grain

Abstract The research was carried out at Chaminuka Training Centre in Mt Darwin district of Zimbabwe. Maize producers in the rural areas are challenged by storage pests particularly the Sitophilus zeamais. Affordable and readily available protectants are needed. A common weed, Tagetes minuta, was assessed for its potential to control Sitophilus zeamais. This provides a sustainable and degradable pesticide to the poor farmers. Maize grain samples arranged in a complete randomized design (CRD) were infected with 32 weevils each. The research was run for 8 weeks with the objectives to determine the efficacy of varying forms of Tagetes minuta on Sitophilus zeamais and to establish the effect of Tagetes minuta on maize grain weight loss. Weevil counts were taken on fortnight bases to establish mortalities. Grain weight loss was assessed using the Thousand Grain Method (T G M). There were variations on treatments with varied forms. The ground Tagetes minuta had the highest effect on both weight loss and weevil mortality compared to un-ground Tagetes minuta (p = 0.001). It was concluded that the ground Tagetes minuta works through a wider spectrum by causing physical and physiological effects on the weevil resulting in mortalities

Advanced material against human (Including Covid‐19) and plant viruses: nanoparticles as a feasible strategy

The SARS‐CoV‐2 virus outbreak revealed that these nano‐pathogens have the ability to rapidly change lives. Undoubtedly, SARS‐CoV‐2 as well as other viruses can cause important global impacts, affecting public health, as well as, socioeconomic development. But viruses are not only a public health concern, they are also a problem in agriculture. The current treatments are often ineffective, are prone to develop resistance, or cause considerable adverse side effects. The use of nanotechnology has played an important role to combat viral diseases. In this review three main aspects are in focus: first, the potential use of nanoparticles as carriers for drug delivery. Second, its use for treatments of some human viral diseases, and third, its application as antivirals in plants. With these three themes, the aim is to give to readers an overview of the progress in this promising area of biotechnology during the 2017–2020 period, and to provide a glance at how tangible is the effectiveness of nanotechnology against viruses. Future prospects are also discussed. It is hoped that this review can be a contribution to general knowledge for both specialized and non‐specialized readers, allowing a better knowledge of this interesting topic.REDES‐ANID. Grant Number: 180003 Universidad de La Frontera. Grant Number: DI20‐1003 FAPESP. Grant Numbers: 2018/08194‐2, 2018/02832‐7 CNPq. Grant Numbers: 404815/2018‐9, 313117/2019‐5 CONICYT/FAPESP. Grant Number: 2018/08194‐2 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. Grant Numbers: 001, ANID/FONDAP/15130015 FCT. Grant Number: PTDC/CTM‐TEX/28295/2017 FEDER POCI Portugal 2020 program COMPETE. Grant Number: UID/CTM/00264/2019 FCT/MCTE

Maize streak virus: a review of pathogen occurrence, biology and management options for small holder farmers

The maize streak disease is a major threat to cereal crops amongst smallholder farmers in sub-Saharan Africa causing up to US$480 million losses annually. It is caused by Maize Streak Virus (MSV) a geminivrus that is indigenous to Africa. The virus is transmitted by at least 11 Cicadulina species, with the cicadulina mbila being the main vector. In addition to cereals, the virus also infects wild grasses. There are 11 known MSV strains designated with letters A to K, according to alphabetic order. MSV-A is the most severe and economically important stain that attacks maize. The other strains attack cereal crops other than maize. The control of MSV is the most effective when cultural and chemical methods are integrated with plant breeding for resistance. While host plant resistance is the best method of MSV management, it is not usually easy to conventionally produce resistance cultivars. Genetic engineering has been successfully employed in producing MSV resistant maize. However, the opponents of genetic engineering have prevented the adoption of the technology by African countries. This means that small holder farmers have to continue growing susceptible cultivars or buy the slightly more expensive conventionally bred cultivars

K nowledge and perceptions of plant viral diseases by different stakeh olders in Zimbabwe’s agricultural sector : implications for disease management.

Plant viruses are major constraints to crop production worldwide, causing US$60 billion losses annually . This st udy assess ed various agricultural sector stakeholders’ knowledge and perceptions of plant viruses in Zimbabwe . Data was collected from six provinces using surveys and participatory rural appraisal methodologies between December 2013 and Oc tober 2014. Maize streak virus , Tobacco mosaic virus , Cucumber mosaic virus , Tomato mosaic virus and Groundnut rosette virus were ranked as the country’s five most important plant viruses by agricultural technical staff . Most ( 72 % ) technical staff rated Maize streak virus as the most important plant virus in Zimbabwe . Over 30 % of farmers were self - taught to identify diseases, while only 15.3% were trained by agricultural extension staff. Most (95.8%) technical staff trained people in disease identificatio n through running short courses, use of demonstration plots and field days. The majority (41.9%) of farmers recommended the use of radio/TV/newspaper broadcasts to improve virus awareness. Only 23.7% of farmers and 41.6% of technical staff had heard about TSWV/ tospoviruses . While most (97.2%) technical staff rated TSWV/tospo viruses as “ fairly important †to “ very im portant †plant pathogens, only 15 . 7 % were able to correctly i dentify tospoviral vectors . The study showed that there is poor knowledge of plant v iruses the stakeholders in the agricultural sector. There is need to train the technical staff in plant virology so that they can disseminate their knowledge to farmers for improved virus disease management

Genome sequence of a tomato-infecting tomato mosaic virus isolate from Zimbabwe

A tomato-infecting tomato mosaic virus (ToMV) isolate was detected in Zimbabwe using lateral flow kits and double-antibody sandwich enzyme-linked immunosorbent assay. Next-generation sequencing and de novo assembly were subsequently performed to determine its genome sequence. The ToMV genome of the Zimbabwe isolate is the second to be reported in Africa.The Kellogg Foundationhttp://genomea.asm.orgam2018Genetic

Genome Sequence of a Tomato-Infecting Tomato Mosaic Virus Isolate from Zimbabwe

A tomato-infecting tomato mosaic virus (ToMV) isolate was detected in Zimbabwe using lateral flow kits and double-antibody sandwich enzyme-linked immunosorbent assay. Next-generation sequencing and de novo assembly were subsequently performed to determine its genome sequence. The ToMV genome of the Zimbabwe isolate is the second to be reported in Africa.The Kellogg Foundationhttp://genomea.asm.orgam2018Genetic