Introducing Pesticides to Smallholder African Agriculture

Managing crop pests has always been a major part of my life. Ever since I was able to handle a hoe and use it for land preparation and weeding, I became a member of our family’s crop management team. Ultimately, hoeing became part of my life because we grew sizeable acreage of maize (corn) and edible beans which we used as staple foods.

Besides hoeing, cultivating maize often required an application of insecticide to prevent stem borers from establishing, damaging the crop, and reducing yield. The insecticide was administered by placing a small amount of a granular formulation into the funnel of each maize plant before tassels emerged. We used no personal protective equipment (PPE) because we knew no better and were given no advice to the contrary. Despite some yield-reducing pest problems occurring in the bean crop, no pesticides were applied in-season.

The next battle with pests came after crops were harvested and stored. The major storage pest at the time was a grain weevil that would infest maize and bean seeds in storage and, to a large extent, render the produce inedible. Consequently, insecticides were mixed with the harvested maize and beans by hand, without PPE, prior to bagging and storing (see Oct. 9, 2017 blogpost). Of particular note here is that once pesticides were applied in storage they could not be removed from stored maize or beans prior to consumption.

Much of what I experienced with pesticide use in Kenya in the 1970s and 1980s is still going on today, especially among rural smallholder farm families. The only difference is that these rural communities now have access to a wider arsenal of pesticides to choose from for their pest management needs. Whereas this might be seen as advantageous to the farmer, we should be concerned that basic pesticide knowledge and understanding is lacking.

What kind of basic knowledge should smallholder African farmers have to handle and apply pesticides?
I became aware of the benefits and hazards of pesticides when I pursued an educational path and career in crop protection. With the knowledge I acquired, I conducted research with pesticides and also taught university courses where I introduced students to the various facets of pesticide use. Presently I have directed my focus to confronting the challenge of pesticide use in Africa. Stepping up to this challenge means that I must strive to ensure relevant information is provided to smallholder African farmers.

Perhaps the starting point is in highlighting pesticides that were/are widely used and have been banned or are problematic.

Tune in for my next series of blogposts as I explore the various facets of pesticides – the good, the bad, and the ugly.

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My Grandmother’s Medicinal Plants and Pesticide Use

Guku Besi 2

Debra Besi Ogada, my grandmother in 1976

In this blogpost, the spotlight is on my late grandmother, Debra Besi Ogada, and the importance of her work as a herbalist (traditional healer) within her rural community in western Kenya. My grandmother grew up in an era when the only medical treatment available was from a herbalist or traditional healer who was valued for knowledge of plants with medicinal properties. Such knowledge included an understanding of the biology and ecology of the plants, when they were to be harvested and used, and the dosage to prescribe for treatment of an ailment.

According to the World Health Organization (WHO), 80% of the population in Africa use traditional medicines for their primary healthcare needs. Of all traditional medicines, about 85% of them are made using plant extracts. Furthermore, WHO estimates that in Sub-Saharan Africa, there is one traditional healer per 500 people whereas there is one medical doctor per 40,000 people. The importance of medicinal plants cannot be overemphasized, and they must be protected for the benefit of Africans. In addition, medicinal plants are a resource for medicine, since most of these plants have not been fully characterized and may have untapped medicinal potential. Medicinal plants are often rare, possibly threatened or endangered, and if herbicides are used without sufficient oversight, as is common in Africa today, the probability of causing local or widespread extinction of the medicinal plants is relatively high. Possible extinction of the medicinal plants is a huge threat to the livelihood of most rural African communities where modern medical facilities are not easily accessible.

A few years ago, as a weed science faculty member at North Dakota State University, I was given the responsibility of developing a case for the use of a herbicide that was not registered for use in potato. Referred to as an Environmental Protection Agency (EPA) Section 18 exemption, permission is sometimes needed when there is an emergency situation that requires a remedy and available options are few. In this particular case, the herbicide was on the path to full registration but had not been cleared by the US EPA. To obtain the special exemption from the EPA, I had to provide assurances that some of the threatened orchid species in North Dakota would not be affected when the herbicide was applied. This I did, and the special exemption was granted for that particular growing season. In Africa, this level of regulation is not available and once a herbicide is available on the market it can be used at the discretion of the buyer.

Towards the end of her life, my grandmother moved from her rural home to live with us in the city because she needed more care. Her absence was an inconvenience to many within her community because they were forced to look for alternative healers or otherwise travel the lengthy distance to see my grandmother and receive treatment. To me, however, having my grandmother living with us was my introduction to a knowledge base that would lead to my career in weed ecology and biology. As a herbalist, my grandmother needed to secure rare plants for her herbal remedies. As she grew older, she often relied on others, myself included, to get the required plants after she had instructed me where to locate them.

Part of my desire to become a weed scientist was to one day follow in my grandmother’s footsteps albeit with a difference. My hope was that I would study the plants that she used in her herbal remedies before the knowledge was lost or plants became extinct. The likelihood of extinction is accelerated by the adoption of herbicides and their widespread use. Improving the knowledge of rural communities to help improve their appreciation of medicinal plants, coupled with a better understanding of pesticide use can help protect these plants for present and future generations. Perhaps too, it will be a step in helping regulators ‘catch up’ and get a handle on ensuring sustainable pesticide use that not only protects humans and the environment, but which also helps preserve medicinal plants, some of which are rare, threatened, or endangered species.

Fansworth, N. R. and D. D. Soerjarto. 1985. Potential consequences of plant extinction in the US and the current and future availability of prescription drugs. Economic Botany 39(3): 231-240.

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The African Pesticide Market

In the 1990s, I learned how the African pesticide market was too small and insignificant for most of the big manufacturers and marketers to focus their attention. However, that notion soon changed when the African continent was confronted by hunger crises which eventually led to the coining of the phrase ‘food security’ used by many professionals involved in international development. The primary focus soon became one of increasing crop yields to ensure Africa became food secure. Consequently, the need for improved technologies became an important facet, thus paving the way for the entry of pesticides, and the burgeoning African pesticide market.

The African pesticide market is extremely difficult to characterize with precision. Nonetheless, the UN predicts that it will continue to grow by at least 3% per year between now and the year 2050. During the same period, Africa’s population is projected to increase from 16 to 25% of total world population, whereas the population of the Americas will stay the same (13%), Europe will decline from 10 to 7%, and Asia will decline from 60 to 54%. Projected population growth alone points to the fact that Africa urgently needs to ramp up food production and in all likelihood pesticides will become a major component of crop production. In fact, pesticide manufacturers and marketers from outside Africa have entered and dominated the pesticide supply landscape. For the most part, the new players market their pesticides but do not provide adequate stewardship to help ensure that their pesticide products are applied properly with minimal harm to humans and the environment. African governments lack the expertise and resources needed to provide adequate stewardship for the numerous pesticide products that are marketed, each with its own target specificity, guidelines for use, etc. Given this background, several highly hazardous pesticides are now available, even in remote villages, to anyone who can afford them.


Agrodealer in his store in Southern Ethiopia.

In recent trips to Ethiopia and Mozambique, I had the opportunity to see firsthand how pesticides, that would require a license to purchase in the west, were available to anyone. I also got to understand how this had become the African reality. For the Ethiopian and Mozambican agrodealers I visited, by selling pesticides they were fulfilling a growing need. They were businessmen with little or no training in safe use and handling of pesticides and, aside from selling pesticide and spray equipment, they also served as a source of information for the farmers they served. The agrodealers recognized the need to provide good advice to the farmers they served and would have welcomed some training but it was impossible to obtain at the time.

Agrodealership in northern Mozambique (left), and pesticides for sale (right).
Individuals selling pesticides at a market in northern Mozambique.

As the pesticide market continues with its exponential growth, the needs for ensuring all users are adequately informed and trained is approaching crisis levels. Over-reliance on pesticide is soon going to become a reality in Africa just as it has become in the west. Most concerning is that Africa cannot afford to sit quietly and let this happen because the consequences are staggering from a health standpoint – some of the meager resources will have to be devoted to health care. In 2012, the UN predicted that expenditure on pesticide-related illnesses in Sub-Saharan Africa will be over $90 billion by the year 2020. Can Africa continue to bear these costs?

How about the impact of pesticides on the environment in Africa?

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Are Pesticides Poisoning African Wildlife?

Farmers in Kenya used carbofuran insecticide to kill mice (left) and mousebirds (top right) and inadvertently killed Mackinder’s eagle owls (bottom left), a threatened species. [Source of images:]

The intentional and unintentional poisoning of wildlife using pesticide was brought to light in a blogpost titled ‘United Against Wildlife Poisoning’ which was posted by Rupi Mangat on September 28, 2017 ( Farmers in Kenya had used the insecticide carbofuran on sliced tomatoes to kill mice and mousebirds. However, Mackinder’s eagle owls, which prey on mousebirds, were also getting killed. Notwithstanding, the Mackinder’s eagle owl is a threatened species which, despite negative cultural beliefs that link owls to misfortune or death, is a source of tourism revenue from bird watchers. Furthermore, the prevalence of some pests can be reduced by the presence of the Mackinder’s eagle owl potentially making the species an important facet of integrated pest management.

Lioness for Blog #9

Pastoralists in Kenya used carbofuran insecticide to poison lions to avenge the killing of their livestock. [Source of images:]

In other examples where pesticides are used against wildlife, the blogpost highlights how some pastoralists in Kenya have used carbofuran to poison lions and other big cats to avenge the killing of their livestock. In addition, carbofuran was used by some to harvest birds meant for human consumption.

As Africa’s population continues its rapid rise, more land will be needed to cultivate the food necessary to sustain the population. Eventually, the boundaries which separate human and wildlife habitats will shrink increasing the likelihood of wildlife being regarded as nuisance pests whenever they venture into human habitats. Because the need to increase food production has ushered in an African ‘Green Revolution’, a dependence on agricultural inputs, particularly crop protecting pesticides, has been one of the outcomes. The pesticide markets have responded by increasing the supply to Africa with highly hazardous pesticides now available in some of the most remote parts of Africa. However, what is lacking is adequate regulation and stewardship. More importantly, there is a need to make sure that the African smallholder farmers who eventually use the pesticide products have the necessary knowledge and skills to ensure proper use and safety to humans and the environment.

What is lacking when pesticides are marketed in Africa is education; making sure that smallholder farmers are aware of the benefits and dangers to enable them to make informed decisions when they choose to use pesticides. Furthermore, raising farmer’s awareness of the benefits of wildlife can be beneficial for conservation purposes especially if tourism revenue can be generated and shared with the farmers.

Despite being a highly effective insecticide, carbofuran was deregistered in Kenya in 2009 by the manufacturer, FMC Corporation. However, there is one product which contains carbofuran that is available in Kenya today ( which may/may not have an impact on the wild animals mentioned above. Besides, there are several other registered pesticides in Kenya which can be used by farmers or rural inhabitants to target wildlife that have become a nuisance, so education in pesticide safety and wildlife conservation needs to be prioritized.

The Challenge of Pest Control for Smallholder Farmers in Africa

Jembe for Blog #7

A worker taking a break from manually weeding a crop field in Kenya. [Source: Francis Ombwara]

Growing up in Kenya my family raised maize, as it was the major staple, along with several other crops. Maize production was laborious and time consuming because of the tasks involved which included land preparation, planting, weed removal, crop dusting, and harvesting all of which were by done manually. Of all these tasks, weeding was the most brutal. It was part of the reason why I decided to become a weed scientist. One of my goals as a weed scientist was to find ways to make it easier to accomplish the task of weed removal efficiently and without the time- and labor-consuming requirements. So I studied weed biology and ecology in order to understand the various aspects of a weed’s life cycle so as to exploit vulnerabilities using mechanical and chemical means and achieve greater weed control that would result in improved crop yield.

Presently, most crop management operations in Kenya have remained the same, as described above, for smallholder farmers. Where tractors and plowing equipment are available, land preparation has become less laborious for those able to hire service providers. However, when it comes to weed control, the task is still primarily a labor-intensive exercise. Most maize is grown in mixtures with other crops such as beans, which make the use of mechanical and chemical control challenging. Ultimately, maize yields are low.

In the face of rising food needs in Kenya, and in Africa as a whole, the weed control method I describe above which do not depend on pesticide applications to protect crops from pests has become unsustainable. First, acquiring the labor to carry out needed operations has become challenging, with many would-be workers opting to look for more rewarding opportunities in urban areas. Second, use of pesticide is out of reach for many smallholder farmers either because of cost or feasibility of applying pesticides in mixed cropping systems.

For those who have production systems which allow them to apply herbicides, the challenge then becomes timing (when to apply the pesticide) and doing so in a manner that is safe to humans and the environment. There are several factors to consider when selecting and applying a herbicide, all of which center on type and variety of weeds targeted for control. Understanding the biology and ecology of the weed is beneficial when you have several that you need to control, with each having its own unique characteristics.

To date, my blogposts have focused on pesticide safety because pesticides are vital agricultural inputs that when used properly will enable Africa to become more food secure. Improper pesticide use has become widespread across Africa among smallholder farmers hence the need for attention on safe use. In addition, I see the current rise in pesticide availability in Africa leading to an over-reliance on pesticides by smallholder farmers that will cause irreparable harm to humans and the environment. Thereby, a focus on pest biology and ecology education will enable smallholder African farmers develop a better understanding of pests that will allow them to embrace a variety of pest management techniques and prevent an over-reliance on pesticides.

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