Why the tomato is under threat

It's impossible to imagine cuisine without the tomato. But an invasive pest is destroying tomato harvests around the globe. How integrated pest management helps.

 

by Laura Angelstorf, editor at Biovision

The tomato originates from Central and South America—as does the invasive pest Tuta absoluta, the tomato leafminer. The name of the moth reveals its capability for destruction. This leafminer can reproduce every month in warm areas, producing up to 12 new generations per year. Furthermore, it can survive the winter also when only partially developed. The moth arrived in Europe in 2006, probably from infested plants or fruits. It did not take long before the entire African continent was confronted with problems from Tuta absoluta infestation.

Total crop failures

This tomato pest can cause complete crop failure. As the tomato is the most consumed vegetable in Africa, it is obvious that the pest can become a social problem. The African continent is already dependent on imports because local production cannot meet the demand. 
In 2018, the moth ruined almost 114,000 metric tons of tomatoes in Kenya, three times the annual production of tomatoes in Switzerland.
The quantitative losses, reflected in particular by the loss of profits of tomato plantations, are accompanied by additional problems. Particularly for smallholder families, who are usually only able to produce small quantities for their own needs  and the loss of the harvest thus eliminates an important source of vitamins, minerals and essential amino acids. 
Additionally, smallholders often endanger their own health by improperly using chemical pesticides, which are expensive and often not successful in the long term. Thus, Tuta absoluta has quickly become a problem that threatens the livelihood of the poor rural population in sub-Saharan Africa.

Sustainable and long-term protection for tomatoes

The International Centre of Insect Physiology and Ecology, icipe, supported by Biovision, sought out a biological pest control method for the Tuta absoluta moth. A parasitoid wasp, also from South America, was adapted to the local conditions in Kenya and Uganda and propagated there. As part of the Biovision project, the parasitoids are now being distributed to the affected regions. Farming families are also being trained in greenhouse hygiene, the correct handling of biopesticides and infestation monitoring. "The strategy of combating the pest with beneficial insects is definitely the key to success. However, it is still important to provide those affected with knowledge on pest management, greenhouse hygiene and the production and use of biopesticides," summarizes Dr. Samira Mohamed, Head of Research of the Integrated Pest Management unit at icipe. 
In accordance with the Biovision principle of knowledge transfer to ensure the long-term independence of smallhollders, the knowledge generated in the laboratory is made available to the general public. 

Pest control is a global problem

The Biovision project is currently designed for a project phase that lasts until 2021. Initially, around 5,000 direct beneficiaries in Kenya and Uganda will be trained and gain experience in biological pest management. "However, we hope to receive further funds to spread the technology in other countries as well," says Mohamed.
 

  • Three small tomato plants sitting on a counter are hit by sun rays from the left.
    The tomato plant is of vital importance in Sub-Sahara African economies.
  • A scientist works on different tomato plants in the lab.
    Scientists of the icipe develop a tailored package for integrated pest control.
  • A tuta absoluta moth sitting on a tomato leaf
    The moth "tuta absoluta" is able to destroy the complete tomato harvest.
  • Two scientists work on tomato plants in the lab.
    Scientists of the icipe - among other things - developed a biopesticide for effective pest control.