The biological pest management strategy Push-Pull can help achieve the Sustainable Development Goals (SDGs) by contributing to ending poverty and hunger. This is the message of a guest article on IISD’s SDG Knowledge Hub, published by Zeyaur Khan, Programme Leader for Push-Pull at the International Centre of Insect Physiology and Ecology (ICIPE) in Kenya, and Samuel Ledermann, Scientific Advisor at Biovision Foundation, which helps to spread the Push-Pull method from farm to farm. The authors argue that the Push-Pull method is a successful example of how a knowledge-intensive solution to the problem of yield losses to maize crops caused by striga weed and stemborers became a proven technology. It is closely linked to many of the 17 SDGs, adopted by world leaders in September 2015: Push-Pull does not only have a beneficial impact on the implementation of SDG 2, which aims at ending hunger, achieving food security and improved nutrition and promoting sustainable agriculture, they write, but also positively impacts SDG 1 (no poverty), SDG 5 (gender equality) and SDG 15 (life on land).

Maize production in Africa is constrained by two major pests: stemborers, which can cause yield losses of 20-80%, and Striga, a parasitic weed that attaches itself to the maize roots and can cause yield losses up to 100%. By the late 1990s, in search of an ecological solution to stemborers, scientists at the ICIPE, Kenya Agricultural Research Institute (KARI) and Rothamsted Research in the UK developed the biological pest management strategy to control the stemborer. The leguminous plant desmodium is planted in between the rows of maize or sorghum. It then suppresses the growth of the striga weed by natural means. The smell of desmodium repels the stem borer moths and drives them away from the main crop (push). Around the fields, the farmers plant napier grass, which attracts female stem borer moths (pull). They place their eggs in the grass where, once they try to bore into the grass, the hatched larvae die in the sticky substance the grass produces. Soils and livestock also benefit from Push-Pull. Like other leguminous plants, desmodium fixes nitrogen from the air with its root nodules. As of early 2017, the number of adopters in East Africa has reached 140,000 farmers.

According to Khan and Ledermann, at the level of SDG 2, the ability to control these two major pests resulted in on-farm maize yield increases in Kenya from less than 1 tonne per hectare to at least 3.5 tonnes per hectare. Furthermore, adapted for drier climate with drought-tolerant varieties, the climate-smart Push-Pull variant results in yield increases for sorghum from less than 1 tonne per hectare to 2.5 tonnes per hectare. This can contribute to achieving SDG 2 target 2.3 of doubling the agricultural productivity and incomes of small-scale food producers by 2030. With regard to SDG1, the authors highlight that these yield gains correspond with positive returns on investment for farmers. In addition, the two companion plants serve as a highly nutritious extra fodder for the cattle that increases milk production. Farmers can also generate an additional income by selling the remaining napier grass.

At the level of SDG 5, Khan and Ledermann say that Push-Pull is a technology mainly adopted by women due to targeted dissemination campaigns. The programme promoting the adoption of Push Pull is accompanied by community-based seed production whereby women’s groups are multiplying desmodium seeds and subsequently earn additional household income. Since desmodium is a nitrogen-fixing plant, Push-Pull also contributes to SDG 15 by reducing soil erosion, improving moisture conservation and increasing carbon sequestration through a reduced need for plowing. Khan and Ledermann are not alone with their opinion: With over 100 scientific research articles published, Push-Pull is a proven and chemical-free agricultural technology to control pests. (ab)