From pansies to poinsettias, growth is what you’d expect inside ColorPoint’s 5 million square feet of greenhouse. But within those acres breed the tiniest of creatures (yes, creatures) too small to see. They’re called nematodes.
Ordinarily, nematodes grow naturally in almost any soil and are harmless to pets, animals or people. Even fully reared, they’re nearly invisible. However, they do have an appetite for insect larvae—early stage pests that harm propagating plants. Not surprisingly, ColorPoint growers are leading the way in exploring Biological Defense Systems (BDS) to lessen the environmental impact of conventional pesticides.
Chad Cagle, ColorPoint’s Kentucky Head Grower, explains: “This is just one way we’re stepping up environmental performance, on our way to an MPS (sustainable quality) certificate.” After using pesticides, the typical re-entry time into a greenhouse zone is 12-24 hours.
Exactly how do nematodes do the job of eradicating insect larvae? “Nematodes attack the fungus gnat, shore fly, and thrip larvae that harm plants,” says Chad. “They’re parasites that search for the host [larvae] and infect, reproduce, kill and leave their host.”
If the movie “Aliens” comes to mind, the life of a nematode is unnervingly similar. But why grow them here?
“We can buy nematodes from a supplier, but in frozen or dehydrated form they lose their efficacy,” Chad said. So he breeds nematodes under controlled conditions using mealworms as hosts. After about 14 days, the breeding ground is strained with water which makes a concentrated “nematode bath” later distributed to young plants.
Getting ready for spring 2016, the greenhouse team is already using 3 nematode species, depending upon the target pest. The unfortunate thrips with a liking to gerberas will soon meet their end.