Deadly plant viruses: thorns in a farmer’s fresh

30th October, 2020
By Arinaitwe Warren

As I wrote this, a google search for plant viruses and human viruses returned 98 million hints on plant viruses and 96 million on human viruses in a second. We seem to have more plant-infecting viral contagions compare to human viruses.

Daily, farmers grapple with effects of viruses transmitted via seed, insects and humans. Like human viruses, once viruses land in a field or landscape, they are difficult to eliminate. For the few years I have been a farmer, I have come face to face with losses inflicted by viruses. They can cause up to 100% yield loss, and the contagion remains for long in the ecosystem.

Here is a personal memory of a scar inflicted by plant viruses. In 2016, we ventured into passionfruit growing (see photo). We sourced local seedlings from a credible supplier. We did all the agronomy, including pest/disease surveillance by the book. The crop flourished. Midway flowering, we noticed garden patches with strange symptoms. Wrinkled fruits and some stony hard. These are signs of passionfruit woodiness virus (PFWV), a virus transmitted by tiny bugs called aphids. Aphid transmitted PFWV and other viruses swiftly and unnoticed. Within a few weeks, the whole garden was infected. As a practising agronomist, I knew the only viable control option was to uproot and call it a season. We rogued the crop and redirected our energies to other enterprises. However, a feeling of I–have-failed remained with me.

Failure is hard to deal with. But this project taught me to fail forward. I kept asking why plant viruses are wickedly smart. Why do they strike at an unexpected time? How do they lobby their transmission vehicles, aphids in the case of PFWV? Why are they hard to exterminate by cultural or chemical means? The quest for answers to these questions motivated me to seek more knowledge.

In 2017, I started a PhD on virus-insect-plant interactions. I am investigating how plant viruses deceptively convince plants to attract insects. Do they use colour? Or they short-change the plant to release sweet-sour smells to lure insects? I am also keen to know when viruses and their insect vehicles relate most. Is it during the day or at night?

Yes, I failed on the farm, but I failed forward. Once the studying is done, I shall return to the frontline to support farmers cope with insect-transmitted viruses and more.

The writer is an agronomist consultant and PhD student at Cambridge University.

1 thought on “Deadly plant viruses: thorns in a farmer’s fresh

  1. This is an informative piece every individual should read. It is a real loss if you don’t pick lessons from a loss. Thank you for sharing your knowledge and experience.

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