The effect of competition on the control of invading plant pathogens

1. New invading pathogen strains must compete with endemic pathogen strains to emerge and spread. As disease control measures are often non-specific, i.e. they do not distinguish between strains, applying control not only affects the invading pathogen strain but the endemic as well. We hypothesise that the control of the invasive strain could be compromised due to the non-specific nature of the control. 2. A spatially-explicit model, describing the East African cassava mosaic virus-Uganda strain (EACMV-UG) outbreak, is used to evaluate methods of controlling both disease incidence and spread of invading pathogen strains in pathosystems with and without an endemic pathogen strain present. 3. We find that while many newly introduced or intensified control measures (such as resistant cultivars or roguing) decrease the expected incidence, they have the unintended consequence of increasing, or at least not reducing, the speed with which the invasive pathogen spreads geographically. We identify which controls cause this effect and methods in which these controls may be applied to prevent it. 4. We found that the spatial spread of the invading strain is chiefly governed by the incidence at the wave front. Control can therefore be applied, or intensified, once the wave front has passed without increasing the pathogen’s rate of spread. 5. When trade of planting material occurs, it is possible that the planting material is already infected. The only forms of control in this study that reduces the speed of geographic spread, regardless of the presence of an endemic strain, are those that reduce the amount of trade and the distance over which trade takes place. 6. Synthesis and applications. Imposing trade restrictions before the epidemic has reached a given area and increasing other control methods only once the wave front has passed is the most effective way of both slowing down spread and controlling incidence when the presence of an endemic strain is unknow

Progress in cassava technology transfer in Uganda

This publication contains the full text of papers presented at a Workshop held in Masindi, Uganda, 9-12 January 1996, and sponsored by the Gatsby Charitable Foundation. During the Workshop the need became evident for additional statistics on the multiplication, distribution and uptake of improved varieties of cassava in the six districts where activities are supported by The Gatsby Charitable Foundation and also elsewhere. The results of a subsequent survey in selected sub-counties of each of the six Gatsby districts are also presented here, together with estimates of the amount of improved material that has been distributed and the area now grown. These latest figures (Appendix 1) represent the best available estimates and in some instances differ substantially from those compiled and presented in the earlier district reports

Practices and constraints of tomato production among smallholder farmers in Uganda

Tomato (Solanum esculentum) is one of the most promising vegetables whose production is being intensified in Uganda. However, tomato yields remain low due to several constraints. The study aimed at identifying production and marketing practices, and constraints affecting tomato productivity in major tomato growing areas of Uganda. A survey was conducted in eight major tomato producing districts using a questionnaire to guide interviews for 240 farmers and 16 key informants. The data were analyzed using SPSS software. Results revealed that tomato production in Uganda is dominated by males who grow them on 0.68 acres of land on average. Most tomato farmers (78.4%) use mono cropping system with varieties Asilla F1 (35.3%), Tengeru97 (21.1%), Rambo (18.1%), Novela F1 (17.7%) and Riogrande (10.3%) dominating. The choice of tomato varieties used by farmers mainly depend on yield potential, pest and disease tolerance and market preference attributes such as long shelf life. In the study area, tomato is mainly fertilized using foliar fertilizers, followed by Diammonium phosphate and cattle manure. The key pests affecting tomato include caterpillars, thrips, worms and whitefly, while bacterial wilt, blight, leaf spots and viral infections are the major diseases. Majority (95.7%) of farmers use chemical sprays (pesticides and fungicides) and 4.3% of farmers used other control methods. The other methods of pest and disease control included rogueing, hand picking, ash, organic extracts, urine and frequent weeding. Average tomato yield was 4,846.3 kg/acre lower than the potential yield of 6000kg/acre. Thirty five percent of farmers market their tomato individually on-farm, 32.8% sell in rural markets, while 32.2% send to the nearest urban markets. The study revealed intensive chemical use accounting for 20% of the production costs, high seed costs (11%) and drought (10%) as the major production constraints impeding tomato production; and price fluctuations, low prices, high transport costs, post-harvest loss on farm, and poor market access as the major marketing constraints. The research findings will aid in the development of new market-oriented, highly productive tomato varieties with improved access to seed and designing initiatives to address production and marketing constraints, which will eventually enhance tomato production

RESISTANCE OF NAPIER GRASS CLONES TO NAPIER GRASS STUNT DISEASE

Napier grass ( Pennisetum purpureum Schumach) is the major livestock fodder under intensive and semi-intensive systems in East Africa. However, the productivity of the grass is constrained by Napier grass Stunt Disease (NSD). The purpose of this study was to identify Napier grass clones with resistance to NSD. Seven introduced Napier grass, from the International Livestock Research Institute (ILRI) gene bank in Ethiopia, and 3 locally available clones in Uganda, were screened for resistance to NSD. Napier grass Stunt Disease severely infected plants tended to have more tillers (r = 0.84, P<0.001), but reduced biomass (r = -0.70, P<0.001) and height (r = -0.88, P<0.001). The reaction of the clones ranged from highly susceptible (clones 16795 and 16792), moderately susceptible (P99, KW4, 16806, 16803, 16785, local and 16814) to resistant (16837). Clone P99 was moderately susceptible to NSD but its harvestable biomass was least affected by disease infection, thus could be, in the interim, utilised in integrated NSD management as the search for more resistant clones is expedited.Le Napier ( Pennisetum purpureum Schumach) est un fourrage important pour l\u2019\ue9levage dans les syst\ue8mes intensifs et semi-intensifs en Afrique de l\u2019est. Par ailleurs, la productivit\ue9 de cet aliment fait face au probl\ue8me de productivit\ue9 de cette herbe qui est affect\ue9 par la maladie du rabougrissement de Napier (NSD). L\u2019objet de cette \ue9tude \ue9tait d\u2019identifier les clones du Napier introduit et localement disponible avec r\ue9sistance au NSD. Sept Napiers introduits en provenance du la banque de g\ue8ne de l\u2019Institut International de Recherche sur l\u2019Elevage (ILRI) en Ethiopie, et trois clones locaux disponibles en Ouganda \ue9taient \ue9valu\ue9s pour leur r\ue9sistance \ue0 cette maladie dans un essai au champ au \u2018National Crops Resources Research Institute (NaCRRI)\u2019 \ue0 Namulonge en Ouganda. La r\ue9action de ces clones variait de hautement susceptible (16795 et 16792), mod\ue9r\ue9ment susceptible (P99, KW4, 16806, 16803, 16785 et 16814) \ue0 r\ue9sistant (16837 et local). La maladie de rabougrissement des plants s\ue9v\ue8rement infect\ue9e tendaient d\u2019avoir significativement plus de talles (r = 0.84, P<0.001) mais avec de la biomasse (r = -0.70, P<0.001) et hauteur (r = -0.88, P<0.001) r\ue9duites. Les clones P99 et 16837 mod\ue9r\ue9ment susceptibles au NSD mais dont leur biomasse n\u2019\ue9tait pas affect\ue9 par by l\u2019infection de la maladie, pourrait \ueatre, dans l\u2019int\ue9rim, utilis\ue9s dans la gestion int\ue9gr\ue9e du NSD pendant que la recherche des clones plus r\ue9sistants continue

The Cost of Acute Respiratory Infections With Cough Among Urban Aboriginal and Torres Strait Islander Children

Introduction: Acute respiratory infections with cough (ARIwC) contribute considerably to childhood morbidity, yet few studies have examined the cost of these illnesses among Australian children. Moreover, of the few studies that have, none are inclusive of Aboriginal and/or Torres Strait Islander children, despite this population experiencing a greater burden of respiratory illnesses. This study aimed to determine the costs of ARIwC among urban Aboriginal and/or Torres Strait Islander children from the perspective of caretakers, the public healthcare system, and employers.Methods: This cost of illness study used data collected from Aboriginal and/or Torres Strait Islander children aged <5 years enrolled in a 12 month prospective cohort study conducted through an urban primary healthcare clinic in Queensland, Australia. Illness-related resource use was collected for each episode of ARIwC reported, and costed at market rates. Linear regression was used to (a) examine cost per episode by season of illness onset and cough duration and (b) examine cost per month of observation by baseline child and family characteristics.Results: During the study period, a total of 264 episodes of ARIwC were reported among 138 children. The total mean cost was estimated to be $AU252 per non-hospitalized episode (95$991 (95%CI 514–1468). Winter episodes and episodes resulting in chronic cough were associated with significantly higher costs per episode. A prior history of wheezing, connections to traditional lands and parent/guardian belief that antibiotics should be given until symptoms resolved were associated with significantly higher cost per child month of observation.Conclusion: The cost of ARIwC in this predominantly disadvantaged population is substantial, particularly for caretakers and this needs to be considered in both clinical management and public health initiatives. The importance of cultural factors on health and burden of illness should not be overlooked. Further research into the prevention of chronic cough may play an important role in reducing the economic burden of pediatric respiratory infections

Supporting Local Seed Businesses : A Training Manual for ISSD Uganda

The training manual is developed in Uganda to train partner organisations in coaching farmer groups to become sustainable local seed businesses. It introduces the Integrated Seed Sector Development Programme in Uganda and the concept of local seed businesses (LSBs). The manual has 5 modules covering selection, monitoring and sustaining local seed businesses; technically equipping local seed businesses, professionally organising LSBs; orienting LSBs to the market and strategically linking them to service providers

The use of common bean (Phaseolus vulgaris ) traditional varieties and their mixtures with commercial varieties to manage bean fly (Ophiomyia spp .) infestations in Uganda

The bean fly (Ophiomyia spp.) is considered the most economically damaging field insect pest of common beans in Uganda. Despite the use of existing pest management approaches, reported damage has remained high. Forty-eight traditional and improved common bean varieties currently grown in farmers’ fields were evaluated for resistance against bean fly. Data on bean fly incidence, severity and root damage from bean stem maggot were collected. Generalized linear mixed model (GLMM) revealed significant resistance to bean fly in the Ugandan traditional varieties. A popular resistant traditional variety and a popular susceptible commercial variety were selected from the 48 varieties and evaluated in pure and mixed stands. The incidence of bean fly infestation on both varieties in mixtures with different arrangements (systematic random versus rows), and different proportions within each of the two arrangements, was measured and analysed using GLMMs. The proportion of resistant varieties in a mixture and the arrangement type significantly decreased bean fly damage compared to pure stands, with the highest decrease in damage registered in the systematic random mixture with at least 50 % of resistant variety. The highest reduction in root damage, obvious 21 days after planting, was found in systematic random mixtures with at least 50 % of the resistant variety. Small holder farmers in East Africa and elsewhere in the world have local preferences for growing bean varieties in genetic mixtures. These mixtures can be enhanced by the use of resistant varieties in the mixtures to reduce bean fly damage on susceptible popular varieties

FinTech revolution: the impact of management information systems upon relative firm value and risk

The FinTech or ‘financial technology’ revolution has been gaining increasing interest as technologies are fundamentally changing the business of financial services. Consequently, financial technology is playing an increasingly important role in providing relative performance growth to firms. It is also well known that such relative performance can be observed through pairs trading investment. Therefore pairs trading have implications for understanding financial technology performance, yet the relationships between relative firm value and financial technology are not well understood. In this paper we investigate the impact of financial technology upon relative firm value in the banking sector. Firstly, using pairs trade data we show that financial technologies reveal differences in relative operational performance of firms, providing insight on the value of financial technologies. Secondly, we find that contribution of relative firm value growth from financial technologies is dependent on the specific business characteristics of the technology, such as the business application and activity type. Finally, we show that financial technologies impact the operational risk of firms and so firms need to take into account both the value and risk benefits in implementing new technological innovations. This paper will be of interest to academics and industry professionals

Embedding cultural competence in faculty : a mixed-methods evaluation of an applied Indigenous proficiency workshop

One of the most pressing issues in Australian society is the gap between Indigenous and non-Indigenous health and life expectancies (Marmot, 2017). Australia agreed with the World Health Organisation’s 2008 Closing the Gap in a Generation report (WHO, 2008), spending approximately 5.6% of government expenditure towards ameliorating this gap (Gardiner-Garden & Simon-Davies, 2012), yet there have been only minimal positive outcomes (Alford, 2015; Gannon, 2018). In applied terms, this means Indigenous people are still dying younger (Anderson et al., 2016), scoring higher on psychological distress (Markwick, Ansari, Sullivan, & McNeil, 2015) and suffering poorer indices on all chronic diseases (e.g. Walsh & Kangaharan, 2016; Thompson, Talley, & Kong, 2017). The level of complexity involved in addressing these “wicked” or seemingly “impossible to solve” health problems is made worse by the lack of any pan-national strategic planning and/or intervention evaluation (Lokuge et al., 2017), even though there has been a plethora of programs and projects designed to improve Indigenous health (see for example, AGPC, 2016). Leaders in health and educational institutions must consider why there is a lack of progress in closing the gap in Indigenous health and life expectancies. Addressing the inequities in Indigenous health requires a determinant of health approach (Mitrou et al., 2014), as 39% of the gap in health outcomes can be explained by social determinates (AIHW, 2017; Markwick, Ansari, Sullivan, Parsons, & McNeil, 2014). The social determinant considered to most reliably predict Indigenous poor health is racism (Kelaher, Ferdinand, & Paradies, 2014; Paradies, 2006; Paradies & Cunningham, 2009; Paradies et al., 2015; Paradies, Truong, & Priest, 2014)

A method for real-time classification of insect vectors of mosaic and brown streak disease in cassava plants for future implementation within a low-cost, handheld, in-field multispectral imaging sensor

Background The paper introduces a multispectral imaging system and data-processing approach for the identification and discrimination of morphologically indistinguishable cryptic species of the destructive crop pest, the whitefly Bemisia tabaci. This investigation and the corresponding system design, was undertaken in two phases under controlled laboratory conditions. The first exploited a prototype benchtop variant of the proposed sensor system to analyse four cryptic species of whitefly reared under similar conditions. The second phase, of the methodology development, employed a commercial high-precision laboratory hyperspectral imager to recover reference data from five cryptic species of whitefly, immobilized through flash freezing, and taken from across four feeding environments. Results The initial results, for the single feeding environment, showed that a correct species classification could be achieved in 85–95% of cases, utilising linear Partial Least Squares approaches. The robustness of the classification approach was then extended both in terms of the automated spatial extraction of the most pertinent insect body parts, to assist with the spectral classification model, as well as the incorporation of a non-linear Support Vector Classifier to maintain the overall classification accuracy at 88–98%, irrespective of the feeding and crop environment. Conclusion This study demonstrates that through an integration of both the spatial data, associated with the multispectral images being used to separate different regions of the insect, and subsequent spectral analysis of those sub-regions, that B. tabaci viral vectors can be differentiated from other cryptic species, that appear morphologically indistinguishable to a human observer, with an accuracy of up to 98%. The implications for the engineering design for an in-field, handheld, sensor system is discussed with respect to the learning gained from this initial stage of the methodology development