Household-level Field Survey of the Pest-Free Fruit Project in Embu County, Kenya. Pest-Free Fruit project, coordinated by Cirad, aims at testing entomovectoring – a new biocontrol technology for the mango fruit fly Bactrocera dorsalis - on two experimental sites, respectively in Kenya and Senegal.

Bactrocera dorsalis is a quarantine pest with adverse effects on livelihood of many horticultural famers across the globe. With origin from Asia, the pest is present in Africa as well and the potential risk of its introduction to a new area is aided by increasing international tourism and trade with great influence from changes in climate and land use. The major economic impact is the loss of export market due to stringent quality measures, increased cost of production and adverse effect on the environment due to excessive use of pesticides to manage the pest. PEST-FREE FRUIT project aims at testing entomovectoring as a biocontrol strategy to manage mango fruit flies.

On 2nd September 2019, a team of 9 led by Dr. Beatrice Muriithi and Charity Muthoni both from Social Science and Impact Assessment Unit, icipe started on questionnaire training using CSPro which aimed at identifying existing famers knowledge and practices in management of mango fruit flies and tracking on farmers’ innovation in order to unearth possible adoption barriers of biocontrol technologies in pest management. After successful training of the survey tool, the team conducted a household level survey in Embu county for 5 days (3rd to 7th September 2019). Embu is a predominant mango growing zones where other IPM components such as use Fruit fly taps have been tested and implemented by icipe.

Photo: Mr. Henry Ngari, an icipe model farmer (second left) explaining to Team of enumerators about orchard sanitation using Augmentorium. Mr Ngari manages B. dorsalis mainly using orchard sanitation and use of fruit fly traps.

Photo: Charity Muthoni, having looking at fruit flies trapped in a farmers’ innovated trap at Madam Cecilia orchard which has more than 600 mango trees, 80% Tommy Atkins and Kent varieties. The average cost of buying a complete set of fruit fly trap is KES. 450 (container plus Bactrolure wing) while the cost of buying the Bactrolure wick alone is KES. 250 hence the farmer minimizes cost by using homemade containers and buying the lure wing alone.

Photo: Mr. Paskwale Njiru George (Right) being interviewed by David Karue (left) during the PEST FREE PROJECT survey. The farmer owns 150 mature mango trees and mainly uses pesticides to manage B. dorsalis. The farmer noted that pesticides are expensive and not very effective since he still incurs losses of up to 15% due to fruit flies’ infestation.

PHOTO: A fruit fly trap hanged in the mango orchard peripherals. This helps in trapping the B. dorsalis as they enter into the orchard before they infest on the fruits. Some of the reasons farmers have stopped using fruit flies’ traps and other IPM components are due to re-infestation from neighboring orchards. One of the farmers acknowledged that IPM works efficiently if practiced at communal level.

Photo: A mango farmer smoking his mango orchard using Mexican marigold, Tithonia diversifolia, pepper and other bitter herbs in attempt to manage mango infesting pests during flowering. The farmer intercrops mango with Macadamia.

Photo: Robert Ouko, Enumerator (Right) in action. The farmer, Mr. Mwaniki Njogu from Kagaari South ward in Runyenjes Sub-county owns a mango orchard with 400 trees. Fruit flies and mango seed weevil are the major pest of economic importance in his farm. He uses indigenous innovations to manage fruit flies by preparing a food bait spray using Molasses and a pesticide. He re-invented the knowledge from the technology of On Spot Food Bait Application learnt from icipe. The method helps him reduce yield losses caused by fruit flies by 90%.

PHOTO: Other than the mango fruit fly (Bactrocera dorsalis), Mango seed weevil causes significant losses to the farmers and acts a barrier to access export market in the Middle East. “The export buyer slices a mango fruit before purchase and if one fruit is infested, all the fruits from that orchard are rejected” explained Mr. Fabian Ngondi. Fabian controls mango seed weevil by typing up the tree trunk using pieces of clothes dipped in used engine oil, a practice he termed as somehow effective.

Photo: Smallholder Horticulture Aggregation and Processing centre owned and managed by Karurumo Horticultural Self Help Group of email address karmaindustries2003@gmail.com. The group does value addition on mango where they make juices, wine and dried mango. The group started with the objective of reducing post-harvest losses on mango, providing better prices to the farmers who are often exploited by brokers and creating jobs to the local community. The Chairman of the group Mr. Aloys Mbogo Mutuku of contact +254 721217321 chaired their monthly meeting which the survey team attended. He was very keen to thank icipe for their intervention but noted that even though the fruit fly traps have helped minimize the losses from fruit flies, there is still more to be done by research organizations and other stakeholders in coming up with more strategies to manage the invasive Bactrocera dorsalis.