Consumers worldwide prefer fruits and vegetables that have been treated with the lowest possible levels of pesticide, if any. Their wish overlaps with the efforts of FAO and the International Atomic Energy Agency (IAEA), which collaborate through a joint division dedicated to nuclear techniques in food and agriculture. The division, with its specialized laboratory, is delivering good results with the so-called Sterile Insect Technique.
In Croatia, the Sterile Insect Technique has already borne fruit – literally and figuratively: benefits to local growers from a pilot programme launched in 2010 amount to a 20 percent annual increase in the production. This was promising enough to scale up efforts in a regional project, where 12 countries in the Balkans and eastern Mediterranean combine their experience, technical specialists and laboratories with a state-of-the-art fly handling and release facility in Croatia.
Bordered by the Adriatic Sea on one side and mountains on all other sides, the picturesque citrus orchards of the Neretva Valley are hampered by the prevalence of the Mediterranean fruit fly or “medfly” – the world's most economically devastating fruit fly pest. These factors make the valley a perfect spot for applying the technology.
Ninety percent of the local population, scattered across some 12 000 hectares, are involved in the citrus industry, producing mainly mandarins (80 percent) for export markets. Early-maturing mandarins offer growers a niche with prime access to the market.
That raises another key issue: not only consumers demand high-quality produce, but also government authorities. There are strict regulations on pesticide residues on fruit, and a quarantine regulation for fruit fly-infested products.
No crops require more intensive use of insecticide than fruits and vegetables. At the same time, the world's farmers spend some US$ 45 billion on chemical pesticides annually. The cost of insecticides is on the rise, making the FAO-IAEA control method a cost-effective and sustainable alternative – in spite of significant initial investment costs.
In effect, the Sterile Insect Technique is a “birth control” method to create pest-free areas or areas of low pest prevalence. It involves the use of ionizing radiation to sterilize mass-reared pest insects, such as fruit flies, which are subsequently released in infested target areas. There, the sterile males mate with fertile wild females but produce no offspring. If the operation is well planned, sterile males should outnumber wild males and cause the fruit fly population to decline.
The FAO-IAEA Insect Pest Control Laboratory in Seibendorf, Austria improved the method, originally developed in the 1950s, with genetic sexing methods. It also developed and harmonized international quality control guidelines for sterile insects.
The project seeks to build countries' capacities for prevention (the best and cheapest option for handling a pest), establish a regional fruit fly surveillance system, implement and test Integrated Pest Management strategies, and ultimately improve the horticultural sector. Considering the transboundary nature of the medfly – and of the technology itself – there is no better approach than a well-coordinated regional effort. This is particularly true in an area dense with orchards and vineyards, putting it at high risk for the introduction of exotic fruit fly species.
The basic reason for using the Sterile Insect Technique is to ensure that crops are protected and growers can produce commercial-sized yields viable for sale and export – even without pesticide application.
And, as the experts point out, insects cannot develop resistance to it.
Source: FAO
