Nematodes to the Rescue?

A week ago today the UPS man came with a small 8-inch Styrofoam cube.  Inside was $60 worth of predatory nematodes, shipped overnight from California.  Randy has not disclosed the cost of the shipping and I think perhaps I had better not ask.  Nematodes are microscopic worms that live in the soil (other species of nematodes live in water).  Some types of nematodes are garden pests, feeding on plant roots, but other kinds are beneficial and feed on insects.
 
How many nematodes do you get for sixty bucks? Twenty million.  What does 20 million nematodes look like?  A couple tablespoons of damp breadcrumbs in little plastic trays.  They are mixed with cool water and sprayed onto damp soil while being careful not to expose them to direct sunlight.  If we have a pest problem that is bad enough that we need to spray something on the crop, this is the best scenario: a targeted biological control.  Targeted because it affects the pest without having a negative effect on any other species biological because it is a living organism.
 
The need for the nematodes will be apparent when you see your turnips.  The larva of a fly species munches on the roots, which causes scaring as the turnip grows.  We had them last year, too, but at the end of turnip season.  Seems the weird weather has shepherded them earlier this year – or is it that our turnips are maturing later?  This is our first time using nematodes, and I am pretty excited to see how successful they are.
 
I am sure this is not the first time you have noticed the evidence of pest damage in your CSA box.  The yellow-margined leaf beetles have been munching the bok choi and mustard greens.  As with the turnips, this is cosmetic damage.  It makes the produce imperfect, but it does not affect the eating quality.  The turnips too ugly to even put in the shares are the ones that Randy and I get to enjoy, and they are just as sweet and crunchy.  So please don’t despair when you see that you have been sharing your produce with the creatures at Tubby Creek Farm.  We know not everything looks perfect, and we are trying to get one step ahead of the pests.
 
Our goal is not to completely erase pests from the farm.  We actually need the pests, in low levels, to keep our beneficial insects around.  The good bugs have to have something to eat.  Our goal is to keep pest populations below the level where they cause significant economic damage, and to do so in a way that increases biological diversity.  I would be happier if all the turnips were perfectly round and white.  Maybe in the fall we’ll be a step ahead and have the nematodes waiting in the refrigerator when the turnips seeds go into the ground.  If you want to learn more about how we manage pests (or fail to manage pests) on the farm, come join us Saturday for our Open House and Bonfire Party for a farm tour!