Seed to plant transmission of Xanthomonas campestris pv. vignicola isolates in cowpea

Open Access Journal; Published: 18 March 2010Seed transmission of Xanthomonas campestris pv. vignicola was investigated to ascertain the importance of seed as a primary source of inoculum for bacterial blight disease in cowpea. The study was carried out using seeds of five cowpea varieties (TVx 12349, IT86D-721, IT82D-889, Ife Brown and TVx 3236) artificially inoculated with three bacterial isolates (Ikenne, Kano and Ibadan), and seeds harvested from infected plants. Results showed that seed to plant transmission caused 6 – 24% post-emergence seedling mortality and 26 – 49% incidence of blight in plants raised from infected seeds. These results support seed transmission of X. campestris pv. vignicola in cowpea and suggest that the distant spread of bacterial blight on cowpea may also be due to seed transmission

Spatial Integration and Price Transmission in Selected Rural and Urban Markets for Cassava Fresh Roots in Nigeria

An advanced time series econometric technique was used to study the interaction between the prices of cassava fresh roots in typical urban-demand and rural-supply markets in Nigeria. The price data cover 95 weeks from week 37 of 2004 to week 28 of 2006. The Augmented Dickey-Fuller (ADF) test was used to investigate stationarity in the prices while Johansen cointegration test procedure, with its associated vector error correction model (VECM) was used to measure the speed of adjustment coefficients that characterized the long-run dynamics of the system. Unit root tests revealed non-stationarity in both urban and rural prices series: in levels the ADF-test statistics were calculated as -1.68 for the rural price and -2.69 for the urban price while in first differences they were -13.98 and -11.91 respectively. Cointegration test revealed that both prices were cointegrated with the trace- and maximum eigenvalue statistics calculated as 18.79 and 16.38, each being statistically significant (p<0.5). The VECM reveals that any positive deviation from the long-run equilibrium would cause the system to respond with decreases in both the rural and urban prices, albeit the rural price responded faster. The impulse response analysis revealed that the rural price was more responsive to shocks emanating from the rural markets. The effect of the shock was calculated as 63.8% using the forecast error variance decompositions. The effect of rural price shock on the urban price appeared to be very infinitesimal at only 6.0% after about 10 periods. The Granger causality test did not reveal any significant causality link between the rural and urban markets prices, suggesting lack of clear trends in price leadership. The finding reveals the lack of predictability and reliability of markets for highly perishable and susceptible agricultural products, like raw cassava roots. There is need to strengthen cassava value chains with greater emphasis on processing and/or direct sale of roots to commercial processors, so as to reduce the volume of transaction of raw roots in the open market, because of the associated price shocks that have perpetually left the rural Nigerian farmer in abject poverty. Keywords: Cassava fresh roots, spatial integration, rural, urban, markets, price leadership, Nigeria

Determinants of productivity of smallholder farmers supplying cassava to starch processors in Nigeria: a baseline evidence

Open Access JournalThe influence of socioeconomic and other household characteristics on the productivity of smallholder farmers supplying cassava to the major commercial starch processors in Nigeria were examined. A multi-stage random sampling technique was used to select 96 farmers working in clusters in selected eight cassava producing states. Data were analyzed using a combination of descriptive and inferential statistics, and multivariate regression techniques. Results revealed the calculated average yield to be 12.39 t/ha thereby leaving an average yield-gap of 7.61 t/ha when compared with an average of 20 t/ha being promoted for farmers under the project. Use of improved varieties (p<0.01) and full-time farming (p<0.05) had significant positive influence on productivity. Also, training, credit use and marital status of farmers influenced productivity positivity at p<0.10 levels. Productivity increased with increase in the variables, but the degree of responsiveness was inelastic in each case. Together the included variables explained 72.1% of the variation in the productivity model. The use of improved cuttings should be accompanied by rigorous but appropriate capacity enhancement programmes to update farmers on modern issues on cassava production and farm management. Empowerment of farmers through linkage to sources of soft loan and other microcredit facilities was recommended, but such efforts should be targeted more on the married and full-time farmers for greater impact

Efficiency and its determinants among smallholder farming units supplying cassava to commercial starch processors in Nigeria: data envelopment analysis approach

Open Access JournalUnderstanding the resource allocation and use efficiency is essential considering the supportive role of agriculture in the advancement of other productive sectors of the economy. Technical efficiency and its determinants were investigated among smallholder cassava-farming and decision-taking units selected from eight states of the southeast and southwest zones of Nigeria. The states’ selection was purposive, being the states in which the IITA-Nestlé cassava starch project was implemented from 2011-2015. However, a multi-stage random sampling technique was used to select a sample of 96 farming units from the clusters established under the project’s out-growers’ scheme. Primary data were collected from the farming units’ heads by administering the pre-tested household survey instrument. Data were analysed using descriptive statistics, inferential statistics, data envelopment analysis, and multivariate ordinary least square regression techniques. The DEA results revealed that majority (73.9%) of the farming units had efficiency scores less than 1 and as such classified as inefficient. Over 30.2% of the cassava farming units had efficient scores greater than 0.8 including 3.1% with scores that ranged from 0.81- 0.99. Farming units with efficiency scores from 0.6-0.8 constituted 17.7% of the sample while those with scores from 0.4-0.6 consist of 33.3%, which also corresponds to the percentage of farming units with efficiencies scores of less than 0.5. Only three variables: cassava farming experience, fertilizer use and quantity of stems used were statistically significant (p<0.05) in explaining cassava farming efficiency. Of these the influence of farming experience was positive while that of fertilizer use and stems were negative. The finding suggests that the elderly and better experienced farmers combined their versatile previous knowledge of farming with willingness to adopt and use improved farming practices to achieve efficiency. Contrary to expectation, fertilizer and stems were associated with less efficiency, a surprising result that could have resulted from misapplication and wastage of the vital resources. The results highlight the need for appropriate training and technical backstopping for the heads of farming units to enhance their knowledge of the good agricultural practices and improve their levels of efficiency

Producing Gari from Cassava: An illustrated guide for smallholder cassava processors

Gari – a popular and increasingly marketable food in West Africa – is one of many food products that can be produced from fresh cassava roots. This practical guide focuses on building the capacity of smallholder farmers and food processors to produce gari as a profitable business. Easy to follow, it uses photographs to illustrate how to design a cassava processing centre, selecting techniques to improve product quality, good hygiene practices and expanding your market

Production du gari à partir du manioc. Guide illustré à l’intention des transformateurs de manioc à petite échelle

Le gari, aliment de plus en plus apprécié et commercialisable en Afrique de l’Ouest, est produit à partir des racines fraîches de manioc. Ce guide pratique porte sur la capacité des petits agriculteurs et des sous-traitants à produire du gari de manière rentable. Facile à suivre, il décrit à l’aide de photographies l’agencement des centres de traitement du manioc, la sélection des machines et techniques permettant d’améliorer la qualité des produits et d’étendre le marché ainsi que les bonnes pratiques d’hygiène

Releasing disease-resistant varieties of cassava in Africa

UPoCA (Unleashing the Power of Cassava in Africa) was part of the long-term, international effort to manage the food price crisis (which started in 2008). The project shared 59 new cassava varieties with at least 11,540 smallholders across seven African countries. The project worked with sub-contracted seed farms, which kept the cassava roots and some of the stems, turning over most of the stems to the project to deliver to other farmers, especially those linked to cassava-based industries. The project established 290 community seed multiplication farms to receive the stems from contractors, and multiply seed for community members. Various pests and diseases limit cassava production in Africa, but cassava mosaic disease (CMD) is the most serious. The new, high-yielding varieties distributed by the project were endowed with resistance to CMD, to other diseases, or to drought. Farmers received training in the rapid multiplication of the stems, to enhance community access to the new material. The project also trained various processors to make cassava graters and mills, and to process high quality flour and other products from cassava. Over time the new varieties (and rapid multiplication, combined with the stimulus of producing for market) increased the production of cassava in the project countries

Sources of resistance to cowpea bacterial blight disease in Nigeria

The development of resistant crop varieties depends on the reliability of the method of screening for resistance. One of the techniques widely used in evaluating field resistance is the field screening method. However, most cowpea varieties regarded as having field resistance are often found to be susceptible in farmers’ fields, where the inoculum density can be higher. This study rescreened 96 cowpea varieties, evaluated earlier in breeders’ fields as resistant to Xanthomonas campestris pv. vignicola, in field and greenhouse under high inoculum pressure. There were significant differences (P ≤ 0.05) in the reactions of cowpea varieties to bacterial blight in terms of disease incidence and severity. Results from the field screening showed that there were 69 susceptible, 25 moderately susceptible, and 2 resistant varieties. In artificial inoculation in the greenhouse IT81D‐1228‐14, IT82E‐16, IT93K‐2271‐2‐2, TVu 1235, and TVu 4630, which were moderately susceptible in the field showed a susceptible reaction. Tvu 12349 and Tvu 15549 gave consistent reactions in the field and in the greenhouse and are therefore good sources of stable resistance to bacterial blight pathogen. Stem canker incidence also varied significantly (P ≤ 0.05) among the cowpea varieties. Seventeen varieties did not manifest canker symptoms

Survival of Xanthomonas campestris pv. vignicola in infested soil, cowpea seed and cowpea debris

Published online: 19 April 2010Field and laboratory experiments were conducted in the Sudan savanna site of IITA's experimental Station, Minjibir, Kano State, to study the survival of Xanthomonas campestris pv. vignicola in infested soil, cowpea seed, and debris. The experiment was conducted in a randomised complete block design with five cowpea varieties over three cropping seasons (from 1996 to 1998). The results showed that the bacterium survived in infected plant debris, seed, and soil but after 8 months off-cropping season, the bacterium was not recovered from the soil. This implies that seeds and plant debris are the major means by which X. campestris pv. vignicola survives through seasons