What Your Crops Say About Weeds

Plants have a lot to say about weed control, we just have to listen. Scientists with the Weed Science Society of America have discovered that corn seeds can detect whether weeds are growing above ground. They make that determination based on light reflected by weeds that penetrates the soil surface. If the seeds sense weeds are lurking, cellular changes are triggered to delay germination, which results in yield losses. Emerged crops respond to weeds with chemical changes that stunt their root system and above-ground growth.

Plant-to-plant communication is being discovered in a number of ways. Jim Westwood is a plant pathology professor at Virginia Tech. His research deals with parasitic plants that attack other plants, steal their resources, and exchange genetic information. Think of them as being hackers of the plant world.

"In addition to taking these messages from the host, it’s actually sending its own messages into the host plan," says Westwood. "You can imagine that the parasite is sending a message into the host cell that says tell the plant to stand down the defenses. To upload sugar so provide nutrients, and don’t put up a big fight because the parasite is trying to persuade the host plant that it’s friendly."

Westwood says finding a way to disrupt this evil dialogue might protect the host plant and give growers the upper hand.

"The more we know about how the parasites interact with their hosts and go about doing their business of attacking and taking resources, the better chance we have to develop crops that are resistant to that." 

Read more about what plants sense that could impact the future of weed control.