Farmers can control striga weed and maize stalk-borer by planting desmodium, a leguminous plant that also increases soil fertility through nitrogen provision and is a good source of feed for cows.
According to the International Maize and Wheat Improvement Center (CIMMYT), striga weed infests over 20m ha of crops in sub-Saharan Africa each year causing losses estimated at Sh100bn thereby affecting over 100m people who depend on agriculture and specifically maize to sustain their livelihoods.
In East Africa, the weed infests over 1.4m hectares yearly with Kenya accounting for 340,000 ha of the total land invaded by the weed.
The striga weed normally causes stunted growth of cereal crops like maize and wheat by attaching itself to the roots of the host plant extracting essential nutrients and moisture necessary for growth.
Research by the Kenya Agricultural and Livestock Research Organization reveals that farmers in areas affected by striga weed can plant desmodium in between the rows of maize to stop the weed which also repels the maize stalk-borer by pushing it away from the plant.
Maize infested by striga weed
Alternatively, farmers planting Napier grass around maize plants intercropped with maize helps push away the female stalk-borer by the desmodium which is then pulled to the Napier where nine out of 10 stalk-borers will be killed by the sticky glue in the Napier stem.
Farmers can obtain desmodium seeds from certified seed merchants such as the Kenya Seed Company with one acre needing two kilos.
The seeds are planted on a fine seedbed on furrows 11/2 feet apart. It is recommended that the seeds be mixed with triple superphosphate fertilizer at the rate of one 50kg bag per acre and covered with a little soil.
Farmers can hand weed their field six weeks after planting or whenever they see weeds appear.
To control aphids and bollworms affecting desmodium, spray with dimethoate chemicals at two weeks intervals at the rate.
An acre can produce 30 to 60kg of desmodium seeds which farmers can sell at Sh1000 per kg.
While green, desmodium can be conserved so as to be used as animal feed during the dru season.