Maize is a vital cereal; an important cash and food crop grown in most continents, owing to its nutritional value and the ease of farming. Although wheat and rice also count as significant cereals, maize is the most widely grown staple food crop in developing countries. However, cultivation of maize has been subjected to some negative effects of insect pests, parasitic weeds, climate change, and infertility of soil among other factors. These have contributed to the low production and sent panic to the masses for fear of food insecurity mainly in Sub-Saharan Africa. Push-Pull is one of the measures that have been introduced to curtail the problem of low crop production in order to eradicate the scarcity of food. Although this technology has not fully revealed its end results, it is addressing the Sustainable Development Goals (SDGs).
Push-Pull technology, a brainchild of International Centre of Insect Physiology and Ecology (icipe) in collaboration with other partners, is an alternative to synthetic pesticides in pest management. The technology which is economical and appropriate was developed to help curb the problem of insect pests like stem borers, parasitic weeds like Striga and soil degradation. It is cost-effective especially to small-scale farmers since it is based on locally available plants, inexpensive external inputs and it fits well with traditional mixed cropping activities. This intercropping strategy entails the use a repellent intercrop and an attractive trap plant. A case in point is intercropping of maize or sorghum with a stem borer moth-repellent legume, Desmodium, surrounded with an attractive host plant like Napier grass, or Brachiaria planted as a trap plant for stem borers. When planted around the maize as a trap plant, the Napier grass attracts stem borer moths to lay eggs on it but does not allow larvae to develop on it; as a result of poor nutrition for the stem borer larvae, very few survive
Additionally, desmodium covers the surface of the ground between the rows of maize putting a chemical that stops striga weed from growing on maize. It does so by stopping root attachment of striga and initiates a suicidal germination of striga reducing its damage. In addition to increased maize yields, it enriches the soil with nitrogen and protects the soil from erosion as it acts as a cover crop. It is also an avenue of making a profit from the sale of fodder and being a continuous supply of cattle feed it translates to increase in dairy products like milk. This not only raises farm income but also improves the nutritional status of the farmer’s family.
Another angle icipe is enhancing through the push-pull technology is the focus on crops grown in dry areas like Sorghum and Millet. This approach encompasses its adaptation to the increasingly dry and hot conditions associated with climate change. The researchers are identifying repellent and trap crops that can be used in a climate-smart version of the technology. In collaboration with Rothamsted Research, icipe has so far selected Greenleaf Desmodium and Brachiaria cv Mulato, as possible component crops in the climate change-adapted push-pull technology. Brachiaria grass is gradually replacing Napier grass because it grows fast with less water and has been found to tolerate dry conditions better than Napier grass.
The impact assessment of push-pull conducted in the previous years to establish its impact on the livelihoods of smallholder farmers, found that the push-pull technology has contributed meaningfully to farmers’ families by ensuring higher and better yield stability. Of the assessed farmers, 75% indicated threefold to fourfold increase in maize yield. For instance, some push–pull farmers reported harvests of more than five tons of maize per hectare, up from previous yields of below one ton per hectare. In addition, the farmers referred to push–pull as a ‘springboard’ for diversifying farming systems, especially through the incorporation of dairy operations using Napier grass and Desmodium as fodder.
These benefits have contributed to increased wellbeing at household and village levels. By selling their surplus grains, milk and fodder, push–pull farmers earn extra income, which they use to pay school fees for their children, purchase household items, and improve their housing, overall nutrition and health. The study therefore suggested that push–pull is “probably the single most effective and efficient low-cost technology for removing major constraints faced by the majority of smallholder farmers in the region, resulting in an overall and significant improvement of their food security and livelihoods”.
Push–pull was also seen to contribute to national food security, rural employment, and better education and increased farming knowledge. Furthermore, the impact assessment found push–pull to be an environmentally friendly technology that is likely to increase agrobiodiversity and contribute to the provision of ecosystem services.
The unfortunate emergence of the fall armyworm, that has recently invaded Africa, has also caused substantial damage to maize and other crops. However, the adapted push-pull technology, developed for control of cereal stem borers in drier agro-ecologies, is believed to be an added tool for the management of fall armyworm. Data collected from at least 250 farmers who had adopted the technology in drier areas of Kenya, Uganda and Tanzania exhibited a reduction of larvae per plant and rated the technology’s superiority in reducing fall armyworm infestation and plant damage rates. Reductions of 82.7% in the average number of larvae per plant and 86.7% in plant damage per plot were observed in climate-adapted push-pull compared to maize monocrop plots. These results established that the technology is effective in controlling fall armyworm with associated maize grain yield increase, and represent the first documentation of a technology that can be immediately deployed for management of the pest in East Africa and beyond.
Icipe’s goal is to continue scaling-up the adoption of push-pull, while addressing one outstanding challenge: making the inputs of the technology, in particular, desmodium seeds, more accessible to farmers. This will involve community seed production and distribution, as well as partnerships with private sector companies to create viable commercial seed production systems.
Icipe has also partnered with government institutions, non-governmental and community- based organisationz, and private sector stakeholders, to intensify dissemination of the push-pull technology. This is aimed at ensuring that its immense opportunities are made accessible to as many small-scale farmers in Africa as possible. The Centre uses a variety of pathways such as field days, farmer teachers and farmer field schools; the mass media, information announcements, video and mobile phone technology. These tools are continuously assessed, to measure gender-specific needs regarding the adoption of the push-pull technology.