It is more important for African farmers at all production levels to successfully implement knowledge that works, than choose between low-tech organic farming and high-tech GM crops. The sensible way of achieving sustainable primary food production in Africa is through Best Agricultural Practices (BAPs), specifically designed for local conditions.
No quick fix for hunger in Africa
GM crops are not a panacea for solving Africa’s food security problems. This is acknowledged by multi-national chemical and seed company, Monsanto, which spearheaded the world’s first commercially viable GM crops. The company’s Roundup Ready crops were genetically modified for tolerance to glyphosate herbicide, and to produce Bt toxins against certain insects. But resistance to specific target pest organisms (weeds and insects) has evolved in both these GM crop varieties in recent times.
Glyphosate and Bt toxin resistance in weeds and insects has been aided and abetted by farmers and service providers not adhering to resistance management guidelines. Due to its efficacy and popularity, glyphosate has often been applied at dosages and frequencies not recommended on the product label, producing resistance in some weeds.
In the case of Bt-crops, which contain genes of the Bacillus thuringiensis bacterium that help ward off borer insects, some farmers fail to follow the legal requirement of planting ‘refuge areas’ to non-Bt crops. This slows down the spread of resistant genes by supporting insects that remain susceptible to the Bt toxins. Organic farming in its purest form involves no synthetic chemical input whatsoever. But it is widely acknowledged that organic agriculture is unlikely to make a significant contribution to primary food production on a global scale, now or in the future.
Organic practices on the continent
In many parts of sub-Saharan Africa, organic practices such as using manure or compost instead of synthetic fertilisers, as well as diversifying crops to deter pests, hold sway for economic and social reasons. Although productivity is generally low in such settings, organic farming remains the main food source for many local communities.
However, chemical intervention is often inadvertently practised in organic farming. In Tanzania, for example, small-scale farmers use rows of strategically placed Mexican sunflower (Tithonia diversifolia), a wild sunflower, to draw whiteflies away from cassava. Mexican sunflower, indigenous to South America, was apparently introduced to Africa, including South Africa, as an ornamental plant. Aromatic chemicals produced and released by plants such as this, act as chemical attractant.
Both commercial and subsistence sugarcane farmers in South African use the African grass, Melinis minutiflora, to repel the stem borer Eldana saccharina. This is one of the most destructive pests in sugarcane production, and natural chemicals in the plant use a ‘stimulo-deterrent diversion’ technique to fight off the insects.
Mere information on climate change has very limited value; this knowledge only gets transformed into workable practices when combined with ‘home-grown’ experience. In this regard, much research needs to be done on the environmental impact of global warming and climate change on weeds, crop pests and plant diseases.
One of the authors of the Intergovernmental Panel on Climate Change’s March 2013 report identified the breakdown of food systems as the greatest threat of climate change. The report states: “Warming of the climate system is unequivocal, and since the 1950s many of the observed changes have been unprecedented over decades and millennia. The atmosphere and oceans have warmed, the amount of snow and ice have diminished, sea levels have risen, and the concentrations of greenhouse gases have increased.”
Environmental impact on pests
Another environmental impact of global warming and climate change is the extent to which weeds, crop pests and plant diseases respond in relation to crop responses. Just one example of this is the spread of brown streak virus across sub-Saharan Africa, which is devastating cassava crops on an ever-greater scale. Higher temperatures are helping to spread the crop’s insect vector, whitefly.
Cassava starch is the staple food of about 250 million people in Africa alone. Genetically engineered cassava plants that resist brown streak virus are being developed, but only four African countries (South Africa, Burkina Faso, Egypt and Sudan) allow the commercial production of genetically modified crops.
Debate on the role of large corporations in our food supply, as well as their use of genetics, are both important but confounding. This can cloud decisions and therefore restrict, or even eliminate, any real benefits to farmers and the broader public. Advocates of biotechnology, a cutting-edge tool in agricultural technology, and proponents of organic farming should rather focus their energies on what will be needed to sustain burgeoning world populations.
Knowledge is crucial
Technological knowledge and tools will be crucial if we want to feed an additional two billion people by 2050, as predicted by the United Nations. Global hunger, a calamity predicted since the 1950s, has been averted only because the ‘green revolution’, which started in the 1960s and continued till the 1990s, made it possible to almost double the yield of key crops such as wheat, rice and maize. In Asia, the yield of wheat and rice doubled during that period, while the continent’s population increased 60%, and human health and general well-being improved concomitantly.
GM crops played no role at the time; they made a real commercial impact only in the mid-1990s. Yield improvements were mainly due to improved chemistry, machinery, and improved crops through conventional plant breeding.
A new green revolution
What is required, in short, is another ‘green revolution’ quantum leap in crop yields for the 21st century to enable us to sustainably feed the world. Supercrops and the associated biotechnology are not the only solution, as superweeds and superbugs also abound. The modern world requires new knowledge, imbedded in both people and technologies, that can be efficiently transferred to commercial as well as subsistence farmers.
To achieve this goal, it is imperative to train people at all levels of farming and service provision in home-grown skills, with the aid of local experts. – Lloyd Phillips
Phone Dr Charlie Reinhardt on 083 442 3427, or email [email protected].