Watermelon Crop Circles

Spotting these Unique Looking Viruses

by Sandy Swegel

Nature is so darn weird some days.  My friend Lara found four watermelons with this a design in them growing in her farm field.  Her neighbors are, um, quirky enough that one of them might have spent the night carving the design.  But a quick google for “crop circles and watermelons” turned up more equally cryptic images.

Most likely these watermelons weren’t carved by industrious aliens.  Designs like this can be caused by spot or mosaic viruses   Last year, we saw lots of the Tomato Spotted Wilt Virus that wiped out tomato plants locally.  Vining plants like cucumbers and papayas are also susceptible.

Most of these plant viruses are spread by insects, often aphids or thrips.  An infected insect goes from plant to plant spreading the virus.  Sometimes the effects are inconsequential and sometimes, as happened with the papaya ringspot virus, most of the crop can be wiped out, endangering the economic status of the entire growing area. Insects often overwinter in debris in the field or nearby, so clearing out your garden after harvest can sometimes break the disease cycle.

Not much you can do once you have the virus. Sometimes they don’t spread, and other times they wipe out the field. Lara only has four fruit so far so she’s hopeful it’s an isolated problem.

Why is tidying up always the answer to most problems?