Science Helps Farmers Cope with Climate Change

Research is underway to find alternative drought-tolerant plants that will be used to control the stem borer pest and the striga weed. This will be achieved by reinforcing an already existing green technology known as “Push-pull”, used by resource poor cereal and livestock farmers in Kenya. The stem borer affects about a third of the maize crop in East Africa.

This development, in a sense, marks a shift in the way organic, environmentally safe technologies for pest and weed control have been viewed in terms of funding. The case is different when it comes to biotechnology research

“It is very difficult to do research if you do not have the facilities and support. There is different money behind genetic engineering, a lot of which goes into research,” Dr. Ricarda Steinbrecher, a molecular geneticist specialized in gene regulation and gene modification, told Steinbrecher has been working on genetically modified organisms since 1995.

In 2008, and after working for three years with hundreds of scientists, the International Assessment of Agricultural Knowledge Science and Technology for Development showed that there is strong evidence indicating that agro-ecological methods of growing crops is the real way forward.

“There are more and more reports coming in that say that this is the way agriculture should move in order to produce more yields in a sustainable way. We have to change our research agenda,” said Steinbrecher.

For a long time napier grass, in conjunction with a companion leguminous plant known as desmodium, has been used to control the pest and weed. But the napier grass cannot withstand prolonged droughts that have become more frequent due to climate change.

This has also meant that small-scale farmers in drier parts of the country have missed out on the benefits of this technology, since napier grass does not do well in drier conditions. These two plants have been used through what has come to be known as “Push and Pull”.

The “push plant” (in this case desmodium, which is the inter-crop plant) produces chemicals that repel the stem borer from the farm. These chemicals, also known as green leaf volatiles, work in a complex way to attract or repel insects.

In addition, desmodium produces a chemical that kill the roots of the striga weed, which is a strong parasitic plant that attaches itself to the roots of maize thus depriving it of nutrients. Besides repelling the stem borer, desmodium also fixes nitrogen from the atmosphere important for soil fertility.

The “pull plant” (in this case napier grass) is planted around the farm to attract the pest away from the farm. Since it emits a sticky substance, it becomes a death trap for the stem borer and its eggs. The protein-rich desmodium is used with napier grass as fodder for livestock.

According to Steinbrecher, agro-ecological organic systems like push-pull produces 80 times more yield than conventional systems and that they are more likely to be sustainable in the long term.

Economic Impact

Kenyan farm

“I could only get two to three liters of milk per day from my goats. But since I began feeding them with desmodium mixed with napier grass, milk production has increased to six liters and some had gone up to eight liters per day.”

Many farmers in Kenya are increasingly finding this true, just like John Otip a 55 year-old small-scale farmer hailing from Rongo District in western Kenya. He says that the technology has improved his dairy goat farming.

“I could only get two to three liters of milk per day from my goats. But since I began feeding them with desmodium mixed with napier grass, milk production has increased to six liters and some had gone up to eight liters per day,” says the father of 11 and a grandfather of two, speaking to He has been using the technology for two years.

Otip says that the technology has improved their living standard, because farmers can work on small plots of land and get higher yields. He keeps seven goats of the British Alpine and Saanen dairy breeds.

And in East Africa maize yields have increased from one ton per hectare to 3.5 tons per hectare, with minimal inputs.

The technology was developed by the International Centre for Insect Physiology and Ecology (ICIPE) and Rothamsted Research of UK among others.

The research is being conducted by ICIPE and is expected to improve food availability for half a million people in dry regions of Kenya, Tanzania and Ethiopia. But its use has been limited to areas that receive fairly good rainfall.

“One of the challenges we have is to adopt this technology to climate change, because in many areas we cannot move because of the long droughts,” Zeyaur Khan, the principle scientist at ICIPE, who invented the technology in 1993 told Its application began in 1998.

According to Khan, farmers who have adopted the push-pull technology do not have to go and look for hybrid seeds.

Remjus Bwana of Yange village of Kisumu West District, Kenya is one such farmer. He has been using the technology since 2007.

“I used to harvest only 20kg of maize in my small plot of land measuring 15m by 20m. But I am able to reap up to 250kg of maize from the same plot since I began using it,” attests Bwana, a father of seven.

Currently, the technology is used by approximately 50,000 small-scale farmers around the Lake Victoria region.

Due to its huge potential in helping small-scale farmers attain food sufficiency and security and improving livelihoods, the European Union (EU) is injecting up to KSH 348 million (US$ 3 million) in funding this new research.

The research will help move the technology quickly to farmers who are not able to benefit from it currently, because they live in dry regions.

Following its successful adoption and encouraging results, Khan explains that there are a lot of opportunities and demand to introduce the technology to cotton.

“This is because the cotton plant has a maximum number of pests, and if we could use this principle with cotton, its production cost will go down,” he says, adding that Africa has lost cotton production because of pests.

The aim of research scientists is to have up to a million farmers in Sub-Saharan Africa adopt the technology by the year 2020.