Survey of farmers’ knowledge of cassava mosaic disease and their preferences for cassava cultivars in three agro-ecological zones in Benin

Background: Cassava is a major staple root crop in Ghana, which serves as a food security and an income generating crop for farming families. In spite of its importance, the crop is plagued with biotic factors such as pests and diseases, resulting in yield and income reductions. Methods: Farmers’ knowledge, attitudes and practices towards cassava pest and disease management were investigated. A mixed method research questionnaire was used to collect both qualitative and quantitative data from 94 cassava farm households across two major cassava growing agro-ecologies. Results: Using descriptive statistics, parametric and non-parametric analysis, our study revealed that farmers’ knowledge on cassava pests was high but low for diseases. Whiteflies (Bemisia tabaci Gennadius), grasshoppers (Zonocerus variegatus), aphids (Aphis gossypii Glover), mealybugs (Phenacoccus manihoti), termites (Isoptera), and grasscutters (Thryonomys swinderianus) were perceived as the most common damaging pests. Farmers’ descriptions showed that disease pathogens attacked foliar tissues, stem and root tissues and caused leaf dropping and die back. Cassava mosaic disease and root rot were the most common diseases; however, disease descriptions suggested the incidence of viral, bacterial and fungal diseases. Some of the farmers observed mixed infections on their farms. The results also showed that only 25.5% cultivated improved varieties. Management actions applied included field sanitation practices and pesticide application. The effectiveness level of the control actions was rated moderately effective. Conclusions: The analysis showed heterogeneity in personal and farm level characteristics of respondents across the two agro-ecologies, but agro-ecologies were independent of the management practices employed. There is a need to improve farmers’ access to improved disease-free planting materials through efficient dissemination pathways and increase farmers’ knowledge on cassava pests, diseases and integrated management through publfic awareness creation and capacity building by extension agents and research institutions. Continued government investment is needed to achieve sustainable outcomes.

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Combining ability of cassava genotypes for cassava mosaic disease and cassava bacterial blight, yield and its related components in two ecological zones in Ghana

Euphytica ◽

10.1007/s10681-013-0936-9 ◽

2013 ◽

Vol 194 (1) ◽

pp. 13-24 ◽

Cited By ~ 13

Author(s):

Elizabeth Yaa Parkes ◽

Martin Fregene ◽

Alfred Dixon ◽

Bright Boakye-Peprah ◽

Maryke Tine Labuschagne

Keyword(s):

Combining Ability ◽

Bacterial Blight ◽

Mosaic Disease ◽

Cassava Mosaic Disease ◽

Cassava Bacterial Blight ◽

Ecological Zones

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Farmers’ knowledge, attitudes and practices towards management of cassava pests and diseases in forest transition and Guinea savannah agro-ecological zones of Ghana

Gates Open Research ◽

10.12688/gatesopenres.13114.2 ◽

2021 ◽

Vol 4 ◽

pp. 101

Author(s):

Benedicta Nsiah Frimpong ◽

Allen Oppong ◽

Ruth Prempeh ◽

Zipporah Appiah-Kubi ◽

Linda A. Abrokwah ◽

...

Keyword(s):

Management Practices ◽

Aphis Gossypii ◽

Mosaic Disease ◽

Phenacoccus Manihoti ◽

Cassava Mosaic Disease ◽

Ecological Zones ◽

Attitudes And Practices ◽

Pests And Diseases ◽

Management Actions ◽

Knowledge Attitudes And Practices

Background: Cassava is a major staple root crop in Ghana, which serves as a food security and an income generating crop for farming families. In spite of its importance, the crop is plagued with biotic factors such as pests and diseases, resulting in yield and income reductions. Methods: Farmers’ knowledge, attitudes and practices towards cassava pest and disease management were investigated. A mixed research questionnaire was used to collect both qualitative and quantitative data from 94 cassava farm households across two major cassava growing agro-ecologies. Results: Using descriptive statistics, parametric and non-parametric analysis, our study revealed that farmers’ knowledge on cassava pests was high but low for diseases. Whiteflies (Bemisia tabaci Gennadius), grasshoppers (Zonocerus variegatus), aphids (Aphis gossypii Glover), mealybugs (Phenacoccus manihoti), termites (Isoptera), and grasscutters (Thryonomys swinderianus) were perceived as the most common damaging pests. Farmers’ descriptions showed that disease pathogens attacked foliar tissues, stem and root tissues and caused leaf dropping and die back. Cassava mosaic disease and root rot were the most common diseases; however, disease descriptions suggested the incidence of viral, bacterial and fungal diseases. Some of the farmers observed mixed symptoms on their farms. The results also showed that only 25.5% cultivated improved varieties. Management actions applied included field sanitation practices and pesticide application. The effectiveness level of the control actions was rated moderately effective. Conclusions: The analysis showed heterogeneity in personal and farm level characteristics of respondents across the two agro-ecologies, but agro-ecologies were independent of the management practices employed. There is a need to improve farmers’ access to improved disease-free planting materials through efficient dissemination pathways and increase farmers’ knowledge on cassava pests, diseases and integrated management through publfic awareness creation and capacity building by extension agents and research institutions. Continued government investment is needed to achieve sustainable outcomes.

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Influence of Abiotic Factors on the Population of Serangium Parcesetosum; A Predator of Cassava Whitefly in Uganda

Journal of Agriculture and Crops ◽

10.32861/jac.52.31.37 ◽

2019 ◽

pp. 31-37

Author(s):

Wamani S. ◽

Acipa A. ◽

Opio M. S. ◽

Ocitti P. ◽

Wanyana B. ◽

...

Keyword(s):

Production Systems ◽

Abiotic Factors ◽

Mosaic Disease ◽

Cassava Mosaic Disease ◽

Predator Population ◽

Ecological Zones ◽

Serangium Parcesetosum ◽

Field Situation ◽

Cassava Brown Streak Disease ◽

Cassava Production

Whitefly is a known pest of economic importance in the cassava production systems of Africa. This pest has been reported to cause losses to cassava through direct feeding damage as well as vectoring cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). Serangium parcesetosum is a known predator of whitefly (Bemisia tabaci) and previous screenhouse and laboratory studies reported that temperature affected the reproduction and survival of this predator. However, these findings lacked precision since they did not depict the field situation. In that regard, it was imperative to initiate a study to help understand the influence of abiotic factors especially temperature and rainfall on the population of S. parcesetosum in the cassava growing fields of Uganda. The study was conducted in two agro-ecological zones of Uganda, namely; North Western Savannah Grassland (Lira) and the Kyoga Plains (Kamuli) in the first rains of 2017. Results revealed that temperature caused an increment of 3.5%, 9.1% (Kamuli) and 1.1%, 1.8% (Lira) for mean adult and larvae S. parcesesotum per plant respectively. On the contrary, rainfall caused a decrease in the population of S. parcesesotum in Lira. Generally, the effect of both temperature and rainfall on the predator population in the field was minimal.

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Influence of Cassava Morphological Traits and Environmental Conditions on Field Populations of Bemisia tabaci

Insects ◽

10.3390/insects12070604 ◽

2021 ◽

Vol 12 (7) ◽

pp. 604

Author(s):

Kasifa Katono ◽

Sarina Macfadyen ◽

Christopher Abu Omongo ◽

Thomas Lapaka Odong ◽

John Colvin ◽

...

Keyword(s):

Relative Humidity ◽

Leaf Area ◽

Bemisia Tabaci ◽

Morphological Traits ◽

Block Design ◽

Mosaic Disease ◽

Cassava Mosaic Disease ◽

Ecological Zones ◽

Positive Effects ◽

Lobe Width

High populations of species in the whitefly complex Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) were reported to cause severe damage to cassava in East and Central Africa. However, reasons for B. tabaci population increases are not well understood. We investigated the effect of cassava morphological traits, temperature, rainfall and relative humidity (RH) on the abundance of B. tabaci. Five cassava genotypes with varying levels of resistance to cassava mosaic disease, cassava brown streak disease, and B. tabaci infestation were planted in three Ugandan agro-ecological zones. The experiment was conducted in 2016 and 2017 in a randomized complete block design. Across all locations, the tallest genotype Alado alado supported the lowest number of B. tabaci adults. In areas with high B. tabaci prevalence, leaf area, leaf lobe width, and leaf lobe number exhibited significant positive effects (p < 0.001) on B. tabaci adult count. Positive effects of relative humidity and negative effects of temperature and rainfall on B. tabaci adult and nymph counts were observed in 2016 and 2017, resulting in low populations in Lira. Evidently, temperatures of 28–30 °C, rainfall of 30–150 mm and RH of 55–70%, and deployment of cassava genotypes of low plant height, large leaf area, and lobe width significantly enhanced B. tabaci population growth.

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Differential Adaptation Strategies By Agro-Ecological Zones In African Livestock Management

10.1596/1813-9450-4601 ◽

2008 ◽

Cited By ~ 3

Author(s):

S. Niggol Seo ◽

Robert Mendelsohn ◽

Ariel Dinar ◽

Pradeep Kurukulasuriya

Keyword(s):

Adaptation Strategies ◽

Ecological Zones ◽

Livestock Management ◽

Differential Adaptation ◽

Agro Ecological Zones

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Effects of Vector Maturation Time on the Dynamics of Cassava Mosaic Disease

Bulletin of Mathematical Biology ◽

10.1007/s11538-021-00921-4 ◽

2021 ◽

Vol 83 (8) ◽

Author(s):

F. Al Basir ◽

Y. N. Kyrychko ◽

K. B. Blyuss ◽

S. Ray

Keyword(s):

Time Delay ◽

Plant Density ◽

Plant Viruses ◽

Mosaic Disease ◽

Plant Diseases ◽

Cassava Mosaic Disease ◽

Maturation Time ◽

Negative Effect ◽

Dynamical Regimes

AbstractMany plant diseases are caused by plant viruses that are often transmitted to plants by vectors. For instance, the cassava mosaic disease, which is spread by whiteflies, has a significant negative effect on plant growth and development. Since only mature whiteflies can contribute to the spread of the cassava mosaic virus, and the maturation time is non-negligible compared to whitefly lifetime, it is important to consider the effects this maturation time can have on the dynamics. In this paper, we propose a mathematical model for dynamics of cassava mosaic disease that includes immature and mature vectors and explicitly includes a time delay representing vector maturation time. A special feature of our plant epidemic model is that vector recruitment is negatively related to the delayed ratio between vector density and plant density. We identify conditions of biological feasibility and stability of different steady states in terms of system parameters and the time delay. Numerical stability analyses and simulations are performed to explore the role of various parameters, and to illustrate the behaviour of the model in different dynamical regimes. We show that the maturation delay may stabilise epidemiological dynamics that would otherwise be cyclic.

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Towards Understanding Variability in Droughts in Response to Extreme Climate Conditions over the Different Agro-Ecological Zones of Pakistan

Sustainability ◽

10.3390/su13126910 ◽

2021 ◽

Vol 13 (12) ◽

pp. 6910

Author(s):

Adil Dilawar ◽

Baozhang Chen ◽

Arfan Arshad ◽

Lifeng Guo ◽

Muhammad Irfan Ehsan ◽

...

Keyword(s):

Pearson Correlation ◽

Principal Component ◽

Mitigation Strategies ◽

Precipitation Extremes ◽

Climate Mitigation ◽

Mean Annual Temperature ◽

Climate Extreme ◽

Ecological Zones ◽

The Mean ◽

Agro Ecological Zones

Here, we provided a comprehensive analysis of long-term drought and climate extreme patterns in the agro ecological zones (AEZs) of Pakistan during 1980–2019. Drought trends were investigated using the standardized precipitation evapotranspiration index (SPEI) at various timescales (SPEI-1, SPEI-3, SPEI-6, and SPEI-12). The results showed that droughts (seasonal and annual) were more persistent and severe in the southern, southwestern, southeastern, and central parts of the region. Drought exacerbated with slopes of −0.02, −0.07, −0.08, −0.01, and −0.02 per year. Drought prevailed in all AEZs in the spring season. The majority of AEZs in Pakistan’s southern, middle, and southwestern regions had experienced substantial warming. The mean annual temperature minimum (Tmin) increased faster than the mean annual temperature maximum (Tmax) in all zones. Precipitation decreased in the southern, northern, central, and southwestern parts of the region. Principal component analysis (PCA) revealed a robust increase in temperature extremes with a variance of 76% and a decrease in precipitation extremes with a variance of 91% in the region. Temperature and precipitation extremes indices had a strong Pearson correlation with drought events. Higher temperatures resulted in extreme drought (dry conditions), while higher precipitation levels resulted in wetting conditions (no drought) in different AEZs. In most AEZs, drought occurrences were more responsive to precipitation. The current findings are helpful for climate mitigation strategies and specific zonal efforts are needed to alleviate the environmental and societal impacts of drought.

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