38 research outputs found
The symptom and genetic diversity of cassava brown streak viruses infecting cassava in East Africa
The genetic and symptom diversity of six virus isolates causing cassava brown streak disease (CBSD) in the endemic (Kenya, Mozambique, and Tanzania) and the recently affected epidemic areas (Uganda) of eastern Africa was studied. Five cassava varieties; Albert, Colombian, Ebwanateraka, TMS60444 (all susceptible) and Kiroba (tolerant) were graft inoculated with each isolate. Based on a number of parameters including the severity of leaf and root symptoms, and the extent of virus transmission by grafting, the viruses were classified as either severe or relatively mild. These results were further confirmed by the mechanical inoculation of 13 herbaceous hosts in which the virulent isolates caused plant death in Nicotiana clevelandii and N. benthamiana whereas the milder isolates did not. Phylogenetic analysis of complete coat protein gene sequences of these isolates together with sequences obtained from 14 other field-collected samples from Kenya and Zanzibar, and reference sequences grouped them into two distinct clusters, representing the two species of cassava brown streak viruses. Put together, these results did not suggest the association of a hypervirulent form of the virus with the current CBSD epidemic in Uganda. Identification of the severe and milder isolates, however, has further implications for disease management and quarantine requirements
Bambara nut: A review of utlisation, market potential and crop improvement
Bambara groundnut ( Vigna subterranea (L.) Verdc.) originated in West
Africa but has become widely distributed throughout the semi-arid zone
of sub-Saharan Africa (SSA). Sharing a high nutritive value with other
widely consumed legumes, bambara has an appealing flavour which is
reflected in demand from small local and niche markets. Despite its
high and balanced protein content, bambara remains under-utilised
because it takes a long time to cook, contains anti-nutritional factors
and does not dehull easily. Bambara yields well under conditions which
are too arid for groundnut ( Arachis hypogea ), maize ( Zea mays L.)
and even sorghum ( Sorghum bicolar ). Its drought tolerance makes
bambara a useful legume to include in climate change adaptation
strategies. Existing bambara products are not well promoted in the
local or international markets and new products are needed that
highlight its inherent nutritional and culinary advantages. A number of
projects on bambara, involving several countries in SSA since the
1980s, have failed to stimulate a sustainable increase in the
production of the crop. The absence of functioning value chains has
been a factor in this failure, as accessible market outlets might
provide the required incentive for smallholder households to obtain
improved seed and invest more of their land and labour in the crop.
There is little documented evidence of trade in bambara but
circumstantial evidence indicates considerable international demand.
More attention should be given, therefore, to market research and
development, with crop improvement programmes being more market-led, if
bambara is to make a greater contribution to household income and rural
development in SSA.Les arachides Bambara ( Vigna subterranea (L.) Verdc.)
d\u2019origine Ouest Africaine ont \ue9t\ue9 largement
r\ue9pandues dans la zone semi aride sub saharienne. Avec sa valeur
nutritive \ue9lev\ue9e \ue0 c\uf4t\ue9 d\u2019autres
l\ue9gumes largement consomm\ue9es, bambara a une saveur attractive
qui se refl\ue8te dans sa demande sur des petits march\ue9s locaux.
Malgr\ue9 sa teneur \ue9quilibr\ue9e en prot\ue9ines, bambara
reste sous utilis\ue9 par suite du long moment de cuisson, contient
des facteurs antinutritionnels et sa coque ne s\u2019enl\ue8ve pas
facilement. Bambara produit de bons redements dans des conditions qui
sont trop arides pour les arachides ( Arachis hypogea ), le ma\ubfs
( Zea mays ) et m\ueame le sorgho ( Sorghum bicolar ). Sa
tol\ue9lance en s\ue9cheresse fait du bambara une l\ue9gume utile
surtout lorsqu\u2019il s\u2019agit des strat\ue9gies
d\u2019adaptation au changement climatique. Les produits existants de
bambara ne sont pas bien promus sur des march\ue9s locaux ou
internationaux et de nouveaux produits montrant tous les avantages
nutritionnels et culinaires sont d\ue9sir\ue9s. Un nombre de
projets sur bambara impliquant plusieurs pays d\u2019Afrique Sub
Saharienne depuis 1980, ont \ue9chou\ue9 de stimuler une
augmentation durable de la production de cette culture. L\u2019absence
de cha\ueenes des valeurs fonctionnelles a \ue9t\ue9 un facteur
de cet \ue9chec, \ue9tant donn\ue9 que des points de vente sur
les march\ue9s accessibles devraient motiver les petits m\ue9nages
pour obtenir des semences am\ue9lior\ue9es et plus investir dans
leurs terres et la main d\u2019oeuvre. Il ya tr\ue8s peu
d\u2019\ue9vidence document\ue9e sur le commerce du bambara mais
des \ue9vidences circonstancielles font montrent d\u2019une demande
internationale consid\ue9rable. Si bambara doit consid\ue9rablement
contribuer \ue0 la g\ue9n\ue9ration des revenus des m\ue9nages
et le d\ue9veloppement rural en Afrique Sub Saharienne, un effort
doit \ueatre mis dans la recherche et d\ue9veloppement, avec des
programmes soutenus d\u2019am\ue9lioration de la culture
orient\ue9s vers le march\ue9
More than canons: teacher knowledge and the literary domain of the secondary English curriculum
Fungitoxicidade de grupos químicos sobre Myrothecium roridum in vitro e sobre a mancha-de-mirotécio em algodoeiro
Farming with fewer pesticides: EU pesticide review and resulting challenges for UK agriculture
EU policy is directed towards significant reductions in pesticide use in the short to medium term. Current European Commission [EC] Directives on pesticide registration and usage, has resulted in the loss from the UK market of some important crop protection products. The continuing review process could result in the removal from sale of many more pesticides commonly used in UK farming. Under Directive 2009/128, the Sustainable Use Directive, National Action Plans for reductions in pesticide use and the implementation of IPM on all farms in member states, will be reviewed by the EC at the end of 2014. As new legislation is introduced and the basis on which pesticides would be removed from use is still undecided, it is difficult for the farming industry to have a clear perspective on which pesticides are at risk and what strategy they need to adopt to comply with current legislation and to design their future pest management plans. Britain and other EU States are faced with having to produce more food profitably and sustainably, using fewer pesticides, while trying to avoid steep price increases. The British Government has adopted a largely voluntary approach to pesticide reduction and implementation of IPM. The future for British agriculture will be a challenging one, relying on fewer active ingredients, with the consequent greater risk of pesticide resistance in the target pests. Farmers will require deeper understanding of IPM and access to information and technical support, if food production is to be sustained at current levels. This review summarises the EU Pesticide legislation, describes its potential impact on pest management and, how UK farming industry is responding to the challenge of farming with fewer pesticides
Farming for balanced nutrition: an agricultural approach to adressing micronutrient deficiency among the vulnerable poor in Africa
Concepts on malnutrition have evolved from an emphasis on protein deficiency through energy deficit, to the realization that food quality in general and an adequate supply of micronutrients in particular, is often more of a problem than food quantity. Throughout the developing world, micronutrient deficiency is one of the most important factors influencing human health, being directly responsible for conditions such as xeropthalmia, associated with vitamin A deficiency and anaemia, due to iron deficiency. In addition, micronutrient deficiency predisposes children to infection and retards recovery from common infections such as malaria, measles and diarrhoea. The groups most at risk from micronutrient deficiency are usually children and those for whom labour for food production is limited by ill health (HIV sufferers), advanced age or intense social commitments (single mothers, for example). There have been numerous health projects in sub-Saharan Africa and elsewhere in the developing world, to address micronutrient deficiency through the distribution of vitamin and mineral supplements, which usually have to be imported. An alternative (or complementary) approach is to promote the inclusion of high quality food crops in the farming system to enrich the diet with essential vitamins and minerals. This agricultural approach to the problem of micronutrient deficiency can provide sustainable solutions, which improve diet quality. An increase in the cultivation of high quality foods such as legumes, fruits and green vegetables, may be able to deliver a balanced diet to households, without necessarily requiring additional land and labour. Agricultural approaches to enhance dietary intake of vitamins and minerals have the additional advantage that they foster community self-reliance, they are sustainable in the absence of external funding, and, offer the opportunity for enhanced income by marketing surplus production. Diet diversification through better use of existing biodiversity offers an immediate means to address poor diet quality and can also include the use of presently available nutritionally enhanced crops, such as orange-fleshed sweet potato
Farming For Balanced Nutrition: An Agricultural Approach To Addressing Micronutrient Deficiency Among The Vulnerable Poor In Africa
Concepts on malnutrition have evolved from an emphasis on protein
deficiency through energy deficit, to the realization that food quality
in general and an adequate supply of micronutrients in particular, is
often more of a problem than food quantity. Throughout the developing
world, micronutrient deficiency is one of the most important factors
influencing human health, being directly responsible for conditions
such as xeropthalmia, associated with vitamin A deficiency and anaemia,
due to iron deficiency. In addition, micronutrient deficiency
predisposes children to infection and retards recovery from common
infections such as malaria, measles and diarrhoea. The groups most at
risk from micronutrient deficiency are usually children and those for
whom labour for food production is limited by ill health (HIV
sufferers), advanced age or intense social commitments (single mothers,
for example). There have been numerous health projects in sub-Saharan
Africa and elsewhere in the developing world, to address micronutrient
deficiency through the distribution of vitamin and mineral supplements,
which usually have to be imported. An alternative (or complementary)
approach is to promote the inclusion of high quality food crops in the
farming system to enrich the diet with essential vitamins and minerals.
This agricultural approach to the problem of micronutrient deficiency
can provide sustainable solutions, which improve diet quality. An
increase in the cultivation of high quality foods such as legumes,
fruits and green vegetables, may be able to deliver a balanced diet to
households, without necessarily requiring additional land and labour.
Agricultural approaches to enhance dietary intake of vitamins and
minerals have the additional advantage that they foster community
self-reliance, they are sustainable in the absence of external funding,
and, offer the opportunity for enhanced income by marketing surplus
production. Diet diversification through better use of existing
biodiversity offers an immediate means to address poor diet quality and
can also include the use of presently available nutritionally enhanced
crops, such as orange-fleshed sweet potato
Grass pea (Lathyrus sativus): Is there a case for further crop improvement?
An ideal legume for resource-poor farmers, grass pea [Lathyrus sativus] is a drought tolerant crop that thrives with minimal external inputs. It is grown on 1 million ha throughout South Asia, mainly as a relay crop after rice. It is also grown extensively in Ethiopia, where it is an important legume for human consumption. Traditionally used for human consumption and as a source of animal feed, this protein-rich legume is favoured for its excellent flavour. There is great potential for an expansion in the utilization of grass pea in drought-prone economies, such as Ethiopia. However, L. sativus produces small quantities of a neurotoxin, β-N-oxalyl –L-α-diaminopropanoic acid (ODAP), which, when consumed alone in large quantities, may cause ‘lathyrism’, an irreversible paralysis of the legs. Lathyrism is a medical condition closely associated with poverty in rural areas. Despite efforts in some countries to discourage production of L. sativus, poor farming communities continue to rely on the crop to supplement their meagre diets. As local land races with high toxin levels generally outperform introduced varieties with lower toxin levels, farmers have little option but to continue to grow their locally-adapted varieties. While there has been some success in breeding grass pea lines with low levels of ODAP, crop improvement programmes are scarce and under-resourced. Facing rising food prices and more frequent natural disasters associated with climate change, we should not neglect the ability of grass pea to provide human and animal feed, under conditions unsuitable for economic production of other legume crops
Reproduction of Meloidogyne javanica on legume crops and some weed species associated with their cultivation in Malawi
Seven legume crops and 18 associated weed species in maize-based, mixed crop small-holdings in Malawi were evaluated as hosts for Meloidogyne javanica in pot experiments..