A researcher samples Striga plants from an invested maize farm at Rongo Migori County. [Sammy Omingo, Standard]

For the last three seasons, he has been planting maize on his one-and-a-half-acre piece of land but getting low yields despite the heavy investments in farm inputs. A parasitic plant known as Striga weed (Kayongo) that has wreaked havoc on the livelihoods of millions of farmers in sub-Saharan Africa is to blame for the losses suffered by Samuel Oraw Adongo, a teacher and farmer from Esikulu village in Matayos sub-county. Striga weed is purple.

“I have tried all means available to eliminate the weed, but all have been in vain,” said Mr Adongo.

Adongo said that the weed surfaces after the second weeding, where it attacks the plant at the root and sucks all the nutrients.

“It leaves the plant with nothing, and eventually it withers and dies,” said Adongo.

For three consecutive seasons, he has planted maize on his one-and-a-half acre parcel of land but has harvested a paltry 10 kilos of maize, which he says cannot sustain the needs of his family.

“I had given up on maize farming for incurring huge losses,” said Adongo, adding that he had started thinking of trying another business to fend for his family. Early this year, Adongo met a group of agronomists from Toothpick Company Limited, who had a solution to his problems.

Toothpick Company is a Kenyan social business firm that has invented the first bioherbicide that controls Striga weed infestations in maize farms in Western and Nyanza regions.

“They were just driving by when they saw that my entire maize plantation had been infested by the weed. We agreed to use my farm as a demonstration farm by planting maize using their new herbicide, and it works,” said Adongo.

He promised that even those I recruit would get good yields after using the new herbicide.

“I am going to harvest eight 50-kilo bags of maize this season. From the research, it was noted that my problem and that of other farms was also due to our acidic soils,” he added.

According to Dorcas Kemboi, an agronomist from Toothpick Company, the weed has caused untold damage to cereal crops such as maize, millet, and sorghum, among other cereal crops in the region.

“This weed with purple flowers has caused untold damage to cereal crops. The situation is dire, the weed is decimating entire fields of maize and sorghum,” said Ms Kemboi. She added: “When the weed attaches itself to the root of the crop, it sucks the nutrients, which prevents the plant from making its own food through photosynthesis and eventually dies.”

Their bioherbicide, KichawiKillTM, uses the virulence-enhanced fungus known as Fusarium oxysporum f.sp. strigae (FoxyT14). “With this innovation, farmers protect their cereal crops and increase their yields. By selecting specific strains of this fungus for their overproduction of amino acid excretion,” said Kemboi.

Kemboi said the herbicide is being piloted in Kenya before being rolled out to more than 20 African counties severely affected by the Striga weed, commonly known as ‘Witch Weed’ among farmers. In Kenya, the pilot project is in seven counties: Kakamega, Kisumu, Bungoma, Busia, Siaya, Homabay, and Migori.

“Striga weed likes acidic soils, which have been destroyed by continuous sugarcane farming, and the use of inorganic fertiliser. The weed thrives well in acidic soils,” said Kemboi,

in the Western region alone, the weed has affected at least 200,000 hectares, causing an estimated loss of Sh100 million annually. According to her, in Sub-Saharan Africa, it results in losses of up to 10 billion US dollars annually.

From their trials on 500 farms, the bioherbicide has shown an increase in crop yields of at least 56 per cent during the long rainy season and 42 per cent during the short rainy season, a move she said is a significant improvement and is changing the lives for smallholder farmers.

The current delivery of the bioherbicide involves two major steps: laboratory coating of primary Foxy T14 inoculum on dowel pins (toothpicks), followed by on-farm production of secondary field inoculum in boiled rice, enabling delivery of vigorous, fresh inoculum directly to the seedbed. The formulated bio-control agent is used by a farmer during planting.

The secondary inoculum is produced by trained smallholder farmers, of whom 85 per cent are women, known as village inoculum producers.

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