23 Nov 2016 Story Ecosystems and Biodiversity

New pest control techniques for Kenya’s flower hub

Flower and horticulture businesses in Lake Naivasha region are changing the way they control pests.  

Nairobi, 22 November 2016: Take a two-hour ride from Kenya’s capital, Nairobi, and you arrive at a lush-looking lake with apparently abundant wildlife and a vibrant horticulture and flower industry.

Despite being a Ramsar “Wetland of International Importance” since 1995, Lake Naivasha has faced some very serious environmental challenges and pressures in the last 30 years, including rapid population growth and fertilizer and pesticide run-off from flower farms.

Rose packhouse

With tens of thousands of Kenyans dependent on the incomes of local flower farm and horticulture workers, lakeside growers are constantly on the look-out to improve the sustainability of their farming methods, and in the last few years there have been a number of positive signs on the environmental front.

Plans such as the Draft Lake Naivasha Integrated Management Plan seek to ensure the region’s sustainable development. Nowadays, more flower growers are harvesting rainwater, using drip irrigation, experimenting with hydroponics, and deploying biological pest control measures known as integrated pest management (IPM), partly as a result of pressure from European buyers and retailers.

View of Naivasha rose farm

IPM involves using bio-control products and bio-pesticides to improve sustainability in agriculture.


The three main bio-tech companies operating in Kenya are Dudutech, Koppert Kenya and Real-IPM, says Anton Jansen, a senior agri-business adviser with the SNV Netherlands Development Organization.

“By identifying the major causes of pesticide use and designing integrated biological solutions to reduce reliance on these chemicals, a reduction in synthetic pesticide use is possible,” says Jansen who in 2008 worked on sustainable agricultural solutions with the Kenya Flower Council and Real-IPM, through the Dutch government-funded Private Sector Investment programme.

Examples of IPM products are insect parasitoids (insects that complete their larval development within the body of another insect which they eventually kill); insect predators; insect killing nematodes (type of worm); insect-killing fungi; soil health products; and sticky traps.


Advising a grower in IPM

Advantages of bio-pesticides
There are a number of advantages of using bio-pesticides compared to chemical pesticides.

“Spraying with synthetic pesticides stresses plants and reduces photosynthetic activity and plant growth,” says Dudutech’s Operations Manager Barnaba Rotich.

“With fewer sprays in the crops there is an increase in production and quality; bigger, shinier, more disease resistant leaves; and better post-harvest storage characteristics.”

According to bio-tech practitioners, biopesticides usually fight their intended pests, while chemicals end up affecting non-target species, including other insects, birds and mammals. Moreover, records have shown that pests tend to become resistant to conventional pesticides, thus proving that they are not a long-term solution; and toxic ingredients in conventional pesticides cause serious negative environmental effects. This is not the case for organic pesticides. Also, most biological pesticide products occur naturally which reduces the cost of production compared to chemical pesticides.

Dudutech says it has facilitated a 90 per cent reduction in synthetic pesticide use in roses between 2003 and 2013 at three sites near Lake Naivasha.

A predatory mite N californicus (left)
attacking a pest (two spotted mite)(right)

“As farmers, we believe that successful IPM is more than products; it is a philosophy of growing that is supported by a number of crop management techniques, physical interventions and biological control. Central to this is a ‘prevention mentality’ as opposed to treatment of pest and disease with agrichemicals,” says Dudutech managing director Thomas Mason.


“We have to learn to work with the whole of nature rather than trying to bang our heads against one part of it at a time. Pesticides tend to have a negative impact somewhere else in nature and in a lake ecosystem biological methods to pest control give better overall results,” says UN Environment expert Niklas Hagelberg. 

Nematodes, fungi and predatory mites
Thrips are tiny, very active and difficult-to-spot insects; they fly into crops from elsewhere, reproduce quickly, and have the potential to cause huge economic post-harvest losses in flowers. A combination of entomopathogenic fungi, predatory mites and entomopathogenic nematodes has been found to attack the flying adults and larvae, killing them much more effectively than any synthetic pesticide.

Kenya Flower Council
The Kenya Flower Council (KFC), was established in 1996 “with the aim of fostering responsible and safe production of cut flowers in Kenya with due consideration of workers welfare and protection of the environment”. KFC says it aspires towards sustainable production, and producer members subscribe to the internationally recognized Flowers and Ornamentals Sustainability Standard, audited annually.

KFC chief executive Jane Ngige, in a speech in March 2016 to mark an award for a new insecticide, said: “It’s gratifying that the new quality product can be integrated with IPM, which is imperative in meeting the ever stringent market requirements on safety and environment protection and sustainability.”