March 21, 2016

avalanche column

March 3, 2016

Root Knot Nematodes (RKN) is one of the most destructive pests of crops on the planet. They ever so slowly strangle a plant by keeping the roots from taking up water and nutrients. In worst case infections the roots are one huge gal that has no resemblance to roots. The plant dies.

It has been several years now that I have had the “pleasure” of their presence in my garden.

These guys are tiny and you need some form of magnification to see them, oh but their handy work is so easy to see. Even in mild infections. The roots look like they have little Mardi Gra beads up and down the root. Quite intriguing until you realize that you have RKN.

When I first became a recipient of these “jewels”, I thought my garden was doomed. In some cases the garden is less productive but for now we have learned to co-exist. This really is an uneasy truce.  Once you have RKN you always will have RKN!!!

In order to live with RKN your garden practices must change.

I suspect I may have gotten RKN from contaminated compostable material that had some root balls with dirt attached.

Ah yes, what to do? Always clean implements in the bed that you have just worked. Washing with a hose will do. Always add compost to your beds. Compost has pathogens that are not kind to RKN. Continually rotate crops, never plant the same crop in the same spot year after year. If only part of a bed is infected always work for the clean parts to the contaminated. A roto-tiller is not compatible with RKN control. This is why I use a shovel. Plant known nemicide or RKN crops such as albion rye, or Idaho gold mustard. Starve the RKN by leaving the bed unplanted and weed free. Frequent cultivating can expose RKN and eggs to the surface where they will die. Use nemicides such as cold pressed neem oil and azaguard. Solarizing beds which is the most effective treatment.

Solariziing is a technique where the top 6 inches of soil is heated to 146 degrees. The soil is sterilized and this also kills a lot of soil pathogens. I find that these solarized beds tend to be very productive after this process. This may be due to the rapid recolonization with beneficial microbes.

I have noticed that the RKN populations in these beds are very slow to “recover”. This may be due to the implementation of many controls. This is the organic approach to gardening; garden vectors are attached and controlled with many different approaches. The biggest component is to always work toward greater soil fertility so that plants can outgrow any attach.

Good luck and happy gardening!!! Questions? I can be contacted at markdirtfarmer@gmail.com. Or more garden notes at redwagonfarm.blogsot.com