An Innovative Approach to Protect Tomatoes and Cucurbits from Emerging Viral Epidemics

European project VIRTIGATION addresses the threat of viral diseases in tomatoes and cucurbits.

The COVID-19 pandemic has profoundly altered our lives. However, humans are not the only ones who suffer from major viral diseases. Horticultural crops, especially tomato and cucurbit crops (zucchini, cucumber, melon, and watermelon), suffer from destructive diseases caused by emerging viral epidemics. And like the human SARS-CoV-2 virus, these plant viruses are not limited by borders.

Major virus diseases in tomato and cucumber: Begomoviruses and Tobamoviruses common symptoms 

Frequently, viral infections are the main factor that limits a crop’s production. In particular, begomoviruses and tobamoviruses threaten tomato and cucurbit crops in countries around the world. They have already caused enormous losses, from 15% to devastating entire crops (complete crop failure). 

Begomoviruses belong to the Geminiviridae family and the genus Begomovirus. The virus can be transmitted by the whitefly vector Bemisia tabaci, causing significant problems in crop (and weed) species of Solanaceae, Papilionaceae, Malvaceae, and Cucurbitaceae (1). 

Common symptoms of the infection are stunted growth, yellow chlorotic mosaic, and leaves curling upwards. In a severe case, infected plants are extremely stunted and produce malformed fruits, causing extreme yield reduction and economic losses (2). 

Symptoms in tomato plants associated with begomovirus infection: Severe plant growth reduction and reduced size of terminal leaves. B. Leaf curling. C. Chlorotic spots. D. Adult whitefly collected in Moëricke traps

Tobamoviruses are among the most important, common, and well-studied plant viruses. With numerous important members (around 37), such as the tobacco mosaic virus (TMV), tomato brown rugose fruit virus (ToBRFV), and cucumber green mottle mosaic virus (CGMMV), tobamoviruses can infect and cause significant problems in over 125 plant species including, tomatoes, cucumbers, tobacco, and orchids (4,5). Depending on the host plant and the virus species, the symptoms of the infection may vary. Infected leaves can become deformed, mottled, or with a mosaic pattern. Sometimes, in case of severe infection, Systemic necrosis and defoliation may be observed in severe infection (and under certain developmental stages and environmental conditions). Symptoms may appear on the fruits, too, decreasing the yield and fruit quality. 

So, protecting horticultural crops from emerging viral epidemics is essential. 

A multidisciplinary approach to decrease yield losses

In this context, the VIRTIGATION project, financed by the European Horizon 2020 program, aims to make a difference. Its objective is to reduce losses in tomato and cucurbit crops by at least 80%. VIRTIGATION’s multidisciplinary approach also includes the induction of natural resistance, the design of plant vaccines, biopesticides, and integrated control or cross-protection strategies.

The project especially aims to use bio-based solutions. Currently, the fight against emerging viral epidemics leads to extensive use of chemical pesticides. This implies greater exposure to residues from these products for growers, consumers, and the environment. So, VIRTIGATION aims to halve the use of chemical pesticides to control plant viruses and their insect vectors. While addressing the threat of emerging viral epidemics to horticultural crops as quickly as possible is crucial, that does not mean we should continue with harmful methods as usual.

Therefore, VIRTIGATION seeks to work with growers and the value chain to protect tomato and cucumber crops with environmentally friendly solutions. The project seeks to co-design its research activities and mitigation strategies in a useful way, especially for key horticultural crops like tomatoes and cucumbers. Thus, our training through our multi-actor network aims to ensure that the project solutions can be easily applied.

We have weathered the COVID-19 pandemic storm with vaccines and other solutions. It is time for the same to be the case for emerging viral epidemics in horticultural crops.

More information about VIRTIGATION:


  2. A. Varma, and V.G. Malathi. Ann Appl Biol. 142(2). 145–164 (2003).
  3. M.N. Sattar. Diversity and Interactions of Begomoviruses and their associated DNA-Satellites. Doctoral Thesis. Swedish University of Agricultural Sciences. Uppsala. pp: 14-16 (2012).
  4. Adams, M.J.; Adkins, S.; Bragard, C.; Gilmer, D.; Li, D.; MacFarlane, S.A.; Wong, S.-M.; Melcher, U.; Ratti, C.; Ryu, K.H.; et al. ICTV virus taxonomy profile: VirgaviridaeGen. Virol. 201798, 1999–2000.
  5. Melcher, U.; Lewandowski, D.J.; Dawson, W.O. (Eds.) Tobamoviruses (Virgaviridae); Elsevier: Amsterdam, The Netherlands, 2021; ISBN 9780123744104. 


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