Plasma lipid profiles discriminate bacterial from viral infection in febrile children

Fever is the most common reason that children present to Emergency Departments. Clinical signs and symptoms suggestive of bacterial infection ar

Development of cassava in Eastern and Southern Africa

Cassava is the major root crop in eastern and southern Africa. It is an important source of calories for the inhabitants of such countries as Uganda, Malawi, and Mozambique. It may also be the best alternative for overcoming the food scarcities caused by frequent droughts in the region

Effect of planting methods and soil moisture on cassava performance in the semiarid Sudan savanna belt of Nigeria

Climatic and edaphic factors are important determinants of the growth and yield potential of an ecological environment. Among other cultural practices, planting methods play a very vital role in the performance of a crop. The effects of planting methods and soil moisture on cassava (Manihot esculenta) performance in the Sudan savanna region of Nigeria were assessed under field conditions at the International Institute of Tropical Agriculture (IITA) in Minjibir, Kano State. Six planting methods in monoculture were evaluated in two crop seasons. These were horizontal planting on furrow or ridge, inclined planting on flat or ridge, and vertical planting on flat or ridge.Two genotypes were compared: TMS 91934, an improved IITA clone; and Dakata Uwariya, a land race. Dakata Uwariya was significantly better (P < 0.05) than TMS 91934 in plant height and root dry matter content; TMS 91934 was better in leaf formation and leaf retention. Ridge-based methods positively influenced root yield production and leaf formation, while flat or furrow methods were advantageous in number of plants at harvest. Horizontal and inclined planting were the best methods in general. Results showed that cassava performance in the Sudan savanna of Nigeria was influenced by genotype, planting methods and soil moisture. Sustainable development of cassava in the semi-arid agroecology essentially depends on the use of clones with good drought adaptation, combined with efficient cultural practices for good growth and yield

Genotypic variability in adaptation responses of selected clones of cassava to drought stress in the Sudan savanna zone of Nigeria

Identification of drought-tolerant and -resistant varieties of cassava is of paramount importance for the maximization of productivity potential in drought-prone areas. Nine improved cassava varieties developed in humid and subhumid agro-ecologies were evaluated for their growth responses and adaptability in the dry savannas of Nigeria. Field trials were set up in two cropping seasons at three different locations. Parameters evaluated included fresh root yield (FRY), fresh shoot yield (FSY), cumulative leaves formed (CLF), cumulative leaf scars (CLS), root dry-matter content (DMC), harvest index (HI), and root cyanogenic potential (CNp). Results demonstrated that varietal response differed with water table site, implying different adaptation responses of varieties to the water regime. Variations in all characters studied were significantly (P<0.05) influenced by genotype, suggesting a strong genetic basis for the phenotypic differences amongst varieties. Compared with variation attributable to location, the genotypic components were strong for FRY, FSY, CLF, CLS, HI and DMC. HI and DMC were not significantly affected by location. CNp tended to increase with increasing drought stress. The significance of genotype × environment effects for FRY suggested that genotypes may be selected for specific adaptation for drought-prone environments. The poor adaptability responses of the majority of the varieties implied that an agro-ecologically targeted breeding scheme for the dry savanna would be a more appropriate approach for the development of drought-tolerant varieties

Effect Of Planting Methods And Soil Moisture On Cassava Performance In The Semi-Arid Sudan Savanna Belt Of Nigeria

Climatic and edaphic factors are important determinants of the growth and yield potential of an ecological environment. Among other cultural practices, planting methods play a very vital role in the performance of a crop. The effects of planting methods and soil moisture on cassava (Manihot esculenta) performance in the Sudan savanna region of Nigeria were assessed under field conditions at the International Institute of Tropical Agriculture (IITA) in Minjibir, Kano State. Six planting methods in monoculture were evaluated in two crop seasons. These were horizontal planting on furrow or ridge, inclined planting on flat or ridge, and vertical planting on flat or ridge.Two genotypes were compared: TMS 91934, an improved IITA clone; and Dakata Uwariya, a land race. Dakata Uwariya was significantly better (P &lt; 0.05) than TMS 91934 in plant height and root dry matter content; TMS 91934 was better in leaf formation and leaf retention. Ridge-based methods positively influenced root yield production and leaf formation, while flat or furrow methods were advantageous in number of plants at harvest. Horizontal and inclined planting were the best methods in general. Results showed that cassava performance in the Sudan savanna of Nigeria was influenced by genotype, planting methods and soil moisture. Sustainable development of cassava in the semi-arid agroecology essentially depends on the use of clones with good drought adaptation, combined with efficient cultural practices for good growth and yield.Les facteurs climatiques et \ue9daphiques sont des composantes importantes d\ue9terminant le potentiel de croissance et de rendement dans un environnement \ue9cologique donn\ue9. Entre autres pratiques culturales, les m\ue9thodes de plantation jouent un r\uf4le, on ne peut plus vital, dans la performance d' une culture. Les effets des m\ue9thodes de plantation et de l' humidit\ue9 du sol sur la performance du manioc (Manihot esculenta) ont \ue9t\ue9 \ue9valu\ue9s en plein champ dans la ferme de l ' Institut international d' agriculture tropicale (IITA) \ue0 Minjibir dans l' \uc9tat de Kano, en zone de savane soudanienne. Six m\ue9thodes de plantation, en condition de monoculture, ont \ue9t\ue9 \ue9valu\ue9es pendant deux campagnes culturales: plantation horizontale en sillons ou en billons, plantation inclin\ue9e sur le plat ou en billons et plantation verticale sur le plat ou en billons. Deux g\ue9notypes ont \ue9t\ue9 compar\ue9s: TMS 91934, un clone am\ue9lior\ue9 de l' IITA et Dakata Uwariya, un cultivar local. En ce qui concerne la hauteur du plant et la teneur en mati\ue8res s\ue8ches des tubercules, Dakata Uwariya s' est av\ue9r\ue9 significativement meilleur (P&lt;0,05) que TMS 91934; par contre, TMS 91934 a pr\ue9sent\ue9 une meilleure formation et r\ue9tention foliaires. Les m\ue9thodes de plantation en billons ont positivement influenc\ue9 le rendement en tubercules et la formation foliaire, tandis que les m\ue9thodes de plantation sur le plat ou en sillons se sont r\ue9v\ue9l\ue9es avantageuses en termes de nombre de plants \ue0 la r\ue9colte. En g\ue9n\ue9ral, les m\ue9thodes de plantation inclin\ue9e se sont av\ue9r\ue9es les meilleures. Les r\ue9sultats ont indiqu\ue9 que la performance du manioc dans la zone de savane soudanienne du Nig\ue9ria a \ue9t\ue9 influenc\ue9e par le g\ue9notype, les m\ue9thodes de plantation et l' humidit\ue9 du sol. Un d\ue9veloppement durable du manioc dans la zone agro\ue9cologique semi-aride repose essentiellement \ue0 la fois sur l ' utilisation de clones dot\ue9s d ' une bonne adaptation \ue0 la s\ue9cheresse et sur le recours aux pratiques culturales efficaces en vue de l'obtention d'une bonne croissance et de rendements \ue9lev\ue9s

A mandioca no Brasil

The current status of cassava cultivation in Brazil is analyzed; aspects covered are the distribution of production, cultivation systems, main uses given to the crop, and problems encountered in the different geographic regions of the country (north, NE, SE, south, and central-west). An overview is also provided of the current structure of research and its potential in the areas of plant breeding and germplasm use; an historical overview is given and the status of different research projects is detailed. Conclusions indicate that production constraints vary from one region to another, but in most of them, cassava is grown without the use of improved technology. This lack of adoption reflects in part the lack of credit facilities and the limited market due to the reduced no. of products, the restricted demand, and unfavorable competition with products favored with the national agricultural policy. The creation of the Centro Nacional de Pesquisa de Mandioca e Fruticultura unified plant breeding research at the national level. (CIAT)Se analiza el estado actual del cultivo de la yuca en Brasil, cubriendo aspectos de la distribucion de la produccion, los sistemas de cultivo y los principales usos y problemas encontrados en las diferentes regiones geograficas del pais (Norte, Nordeste, Sudeste, Sur y Centro-Oeste). Tambien se proporciona una vision de la estructura actual de investigacion y su potencial en las areas de fitomejoramiento y utilizacion de germoplasma; se presenta un recuento historico y se detalla el estado en que se encuentran diferentes proyectos de investigacion. Se concluye que las limitaciones a la produccion varian de region a region, pero en su mayoria la yuca se cultiva sin el uso de tecnologias mejoradas. Esta falta de adopcion refleja un poco la falta de estimulo crediticio y la limitacion del mercado, debido al reducido no. de productos, la restriccion de la demanda y la competencia desigual con productos mas favorecidos por la politica agricola nacional. La creacion del Centro Nacional de Pesquisa de Mandioca e Fruticultura unifico los trabajos de mejoramiento genetico a nivel nacional. (CIAT

Performance of various cassava clones in the dry savanna region of Nigeria

Cassava (Manihot esculenta Crantz) crop is widely known adapt to variable drought conditions. Due to the lack of adapted and high-yielding cultivars tolerant to the prevalent biotic and abiotic stresses, cassava is yet to find a wide and appropriate niche in the farming systems of the African dry savannas. Research aimed at improving adaptation to dry environments is under way. Field studies conducted at two lowland sites in the northern Guinea and Sudan savanna zones of Nigeria revealed a wide genetic variability in adaptation among African and introduced Latin American germplasm. Significant genotypic variability for stomatal response to dry weather fibrous root development, leaf stay-green ability, tuberous root yield and apparent water-use efficiency have been noted. Such variable mechanisms of adaptation associated with drought resistance are currently used as selection criteria in the IITA breeding programme to improve and sustain the cassava production in these dry savanna zones

Crescimento, fotossintese e eficiencia do uso de nitrogenio em milho, feijao e mandioca submetidos a dois niveis de N no solo

Growth and N uptake in pot-grown maize, beans, and cassava were evaluated under 2 levels of soil N at CIAT-Palmira (Colombia). The lower amount of the element reduced its uptake by the 3 species, resulting in lower tissue concn., especially in the leaves. Under low N, DM accumulation was also reduced 5 wk. after planting for maize and beans, and 7 wk. after planting for cassava. Higher amounts of N in the soil increased leaf expansion and photosynthesis (Pn) in maize and beans 3 and 4 wk. after planting, resp., and in cassava after 7 wk. Cassava plants tended to increase N-use efficiency, slightly but nonsignificantly, under low N. Maize used N more efficiently; however, the existence of a real difference between crops cannot be affirmed due to the reduced soil N concn. (AS