Stepping up the fight against Tuta Absoluta in Kenya with safer and sustainable biocontrol products

Tomato is one of the most important vegetables grown by farmers in Kenya and plays an important role in generating employment and income. However, tomato production is limited by many factors, the most important of which are insect pests. Tomato farmers tend to control tomato pests with pesticide sprays, but these pose risks to the environment, food safety and health.

Tomato leaf miner: Tuta Absoluta

Collaboration CABI and Koppert

In order to demonstrate to farmers the benefits of biological control within an integrated approach, CABI and Koppert Biologicals Systems Ltd finalized a project to demonstrate the effects of the use of biological pesticides and Integrated Pest Management (IPM) for the control of the tomato leaf miner (Tuta Absoluta) in Kenya. This project was funded by the Dutch Ministry of Agriculture, Nature and Food Quality. CABI has expertise in biological control and integrated pest management while Koppert is a worldwide supplier of biological pesticides. The IPM regime mainly used a beneficial insect (natural enemy), Macrolophus pygmaeus (MIRICAL), the pheromone trap system (Tutasan + Pherodis) and good agricultural practices.

The project focused specifically on the biological control of the tomato leaf miner: Tuta Absoluta. Since 2014, tomato leaf miner has been the biggest threat to the sustainable production of tomatoes in Kenya. Nearly 98% of Kenyan tomato farmers' are affected by this pest and when pesticides are used as a control method, only 27% of farmers say they have successfully controlled the moth.

The tomato leaf miner belongs to the family Gelechiidae. The species is oligophagous and feeds mainly on species from the nightshade family (Solanaceae). The main host plant is tomato, but potato, eggplant, pepper and tobacco are also affected, as well as weeds such as Datura stramonium, Lycium chilense and Solanum nigrum.

Beeld: ©CABI / CABI
The impacts of Tuta absoluta can be severe, with yield loss reaching 100%

Training to increase knowledge on biocontrol products

Through training and field demonstrations farmers were shown how insect pests can be controlled with biological solutions. The farmers and extension workers trained are able to continue with awareness creation about the technologies. The trained extension workers in turn have trained more farmers in their sub counties. This has ensured that more tomato farmers are informed of the available biological methods to control the Tuta absoluta.

©CABI
CABI staff explain to a farmer how biological control can alleviate the Tuta problem on her farm

The training and awareness creation for tomato farmers have proved successful. Telephone interviews with trained tomato farmers show that the training gave them more knowledge of the various biological control practices for the tomato fly. All farmers surveyed were aware of the use of (Tutasan and delta traps), 98% of the farmers were aware of the sticky traps and 92% of them knew about the use of Trianum for the management of soil borne pathogens. The farmers also mentioned other aspects that are crucial to sustainable control of Tuta absoluta, including using chemicals as the last resort for pest control (60%) and spraying only when the pest population has reached a certain threshold level (50%). Farmers also pointed out the various important benefits that biological controls bring to them, including reduced pesticide spraying (50%) and lower expenditure, better yields and less labor input (48%).

Due to the increased knowledge about biological approaches of controlling insect pests, tomato farmers are also able to save more money. Farmers' average expenditures on pesticides and labor were 39,000 KES and 35,957 KES per hectare, respectively, before the project, compared to 23,220 KES and 31,087 KES after the demonstrations and training – an average reduction of 20,650 KES (188 USD). Spray labor decreased from KES 11,649 to KES 6,780 per acre.

Would you like to know more about Managing Tuta Absoluta, please watch a video here, ordownload the training manual "Integrated management of Tomato leaf minor (Tuta absoluta) and other pests in Kenya" via this link.

©CABI
Farmers attend a field day at Mr. George’s farm in Kimana

Field experiences of tomato farmers

A tomato farmer from the Juja farm in Kiambu County said, after a field demonstration of the Tutasan on his farm, “I heard about these products from my farmer friend, but I did not visit this farm. I am delighted that my farm has been selected for farmers to learn hands-on and see how Tutasan is placed and operated at farm level. I am surprised to see that many of the Tuta pests have been trapped within minutes. This is a product with which I can reduce the production costs I incur on chemicals.”

The Shabangu Farm, Juja are already using some integrated pest management (IPM) methods for managing Tuta absoluta and looks forward to more effective methods. 

“On our farm we already use IPM but seek more effective IPM technologies and bioproducts to manage Tuta  absoluta rather than chemical use. The challenge is always availability,” said Mr Ongeri, farm manager Shabangu Farm.

A Kiambu County Horticultural Crops Officer noted that farmers' knowledge and ability to use the technologies is a critical step to properly introduce the technology. He went on to say that "IPM does not start in the middle crop life cycle, but rather from the beginning at the nursery level before transplanting. A rigorous campaign allows for wider acceptance of safer methods of controlling common agricultural pests that are also environmentally friendly.” He saw that after their training, farmers in the Kalimoni district of Kiambu had come up with a slogan of "Start well and end well for sustainable tomato cultivation" to always remind them of pest- and disease-free tomato cultivation.

In case of questions please contact Linda Likoko, Projects Administrative Officer with CABI via l.likoko@cabi.org or Harrison Rware, Monitoring and Evaluation Officer -Africa with CABI via h.rware@cabi.org.

For any other agricultural questions to the Agricultural Counsellor feel free to contact us via nai-lnv@minbuza.nl. For the latest updates follow us on twitter @NLAgriKenya or register for our newsletter by sending an email.