Fungicide Spraying is Critical for African Potato Production

African Potato Fields Fungicide Treated (L) Untreated (R)

African Potato Fields Fungicide Treated (L) Untreated (R)

Potato consumption has increased dramatically in Sub-Saharan Africa in the past ten years as more people have moved to cities and have diversified their diets. Potato production has increased to meet the demand through the planting of more fields with potatoes which are encroaching on forestland. Potato yields remain low in Africa primarily due to damage from the late blight disease. Increasing farmer knowledge about late blight and the importance of fungicide recommendations could dramatically increase potato yields.

“Potato cultivars grown in Uganda have low levels of general resistance to late blight. As such, most commercial potato farmers rely on fungicide applications for control of Phytophthora infestans, the causal agent of late blight.

Potato has become an important staple and cash crop in the highlands of eastern Africa. These areas experience moderate temperatures (about 15–22°C) and receive relatively high amounts of rainfall (>1200 mm per year) that are favourable for potato production. However, these same conditions favour severe epidemics of late blight, and as such, late blight is a major limitation to potato production in high humid elevations.

In Uganda, potato late blight has been a serious problem since the introduction of the crop into the country in the early 1900s… During the 1990s, six varieties with resistance to late blight were released. However, resistance to late blight in these cultivars has since been overcome and significant yield losses experienced. Additionally, susceptible varieties are still greatly desired by farmers due to their good agronomic characteristics. Invariably, fungicides must be used to ensure disease control.”

Authors: Kankwatsa, P., et al.
Affiliation: Department of Crop Science, Makerere University, Uganda.
Title: Efficacy of different fungicide spray schedules for control of potato late blight in Southwestern Uganda.
Source: Crop Protection. 2003. 22:545-552.

Cowpea, A Major Source of Protein in Africa, Requires Insecticide Applications.


Cowpea Damage From Insects

Cowpea (also known as black-eyed pea) originated in Africa and is the major source of plant proteins in the diet of rural populations in sub-Saharan Africa. Insect pests pose the greatest threat to cowpea production. The crop is attacked at every stage of its growth by insects. Since the late 1970s, extensive studies on insect pests of cowpeas have been conducted at the International Institute of Tropical Agriculture (IITA). IITA’s Guide to Cowpea Production in West Africa states that generally, 2-3 sprays are required for a good crop of cowpea.

“Cowpea is one of the most important food and forage legumes in the semi-arid tropics.

Despite cowpea’s importance and high yield potential in the Nigerian savannas, insect pest attack is a major constraint upon production. Severity can vary, and sometimes lead to total yield loss.

High levels of insect resistance are not available in current cultivars.

Insecticide application is the most widely known means of a pest control method in cowpea; it is not otherwise feasible to grow cowpea commercially. Farmers can improve yield 10-fold if insecticides are used.”

Authors: Kamara, A. Y., et al.
Affiliation: International Institute of Tropical Agriculture, Nigeria.
Title: Integrating planting date with insecticide spraying regimes to manage insect pests of cowpea in north-eastern Nigeria.
Source: International Journal of Pest Management. 2010. 56[3]:243-253.

To Increase Income and Competiveness, Public Policy Should Educate African Maize Farmers About the Benefits of Using Herbicides

Weedy Maize Field: Africa

Weedy Maize Field: Africa

Maize consumption is a major source of calories for millions of people in Sub-Saharan Africa. Within the next few decades, the majority of people in Sub-Saharan Africa will be living in cities. Countries in eastern and southern Africa are increasing imports of staple foods, including maize. In order to be competitive, African farmers need to reduce the cost of producing a unit of maize. Herbicide adoption would greatly reduce costs of growing maize and lead to greater yields and farmer income and competiveness.

“Rural smallholder production remains highly labor-intensive. On average, family labor accounts for 62% of the total cost of maize production in Zambia’s small- and medium-scale farm sector. Promoting the identification and adoption of practices and technologies that save labor and/or identifying labor-productivity-enhancing technologies through research and development will therefore help to make Zambian maize more competitive and allow farmers to maintain profitability even at lower producer prices.

Although only 3% of fields had herbicides applied, regression results suggest the benefits of its use are quite high. All else equal, applying herbicides increases gross margin between ZMK 363,700 to ZMK 376,300 per hectare planted… The magnitude of this effect is fairly large compared to the national average margin of ZMK 1,108,542 (in other words, at the mean, herbicide use would increase gross margins by roughly a third). …these results indicate that public policy measure should be considered to educate farmers about the benefits of herbicide application, as its contribution to smallholder income growth and regional competitiveness may be comparable to and highly synergistic with increased fertilizer use.”

Authors: Burke, W. J., et al.
Affiliation: Zambia Food Security Research Project (FSRP)
Title: The cost of maize production by smallholder farmers in Zambia
Source: Food Security Research Project. Working Paper 50. March 2011. Available at: