Q. Will the diatomaceous
earth I have used in my garden and around fruit trees kill beneficial
nematodes?
A. Diatomaceous earth has the same effect on beneficial
nematodes as any other nematode. I don’t know of any solid research that shows
diatomaceous earth will reduce nematode populations. You might be wasting your
money.
When
nematodes are damaging plants, most recommendations are to mix compost into the
soils to reduce nematodes populations and encourage more rapid growth. Some
fruit trees such as stone fruits are grown on rootstocks, such as Nemaguard©, that are somewhat
resistant to nematodes.
Some
sources will tell you to grow varieties of vegetables resistant to nematodes,
reduce nematode populations periodically using a technique called “soil
solarization” or abandon the spot. I wish they were easy to control but they
are not.
My parents in Florida say they kill nematodes off by covering the area with black tarp and letting the sun bake them dead. Apparently this is common practice there, ever hear of it?
ReplyDeleteYes, a very similar technique is called soil solarization but uses clear plastic instead of black plastic. The black plastic is not as effective as clear plastic. It is a temporary solution because it reduces or kills off a portion of the nematode population but not 100%. This reduction in numbers allows you to grow for a short period of time until the populations increase from those remaining. You can read more about it at http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74145.html
DeleteOkay, you seem to be missing the point. Are the beneficial nematodes are harmed by the DE, which has already been applied in this case. Should I or should I not apply the beneficial nematodes into soil already treated with DE??
ReplyDeleteThere are some specific requirements when adding beneficial nematodes to the soil such as time of year and moisture content of the soil . Talk to your beneficial nematodes supplier but my understanding is that beneficial nematodes are not hurt by diatomaceous earth
DeleteMy understanding is that if something kills bad nematodes it will kill good nematodes.
ReplyDelete