Re: [compost_tea] Nematodes

From: Michael Harvey (mharvey@westnet.com.au)
Date: Tue Feb 04 2003 - 07:46:37 EST


---- Original Message -----

  As I opened this message, McAfee virus scan blocked the attachment Mike i=
ncluded, saying it is unsafe. Thought everyone might want to know this.

  Susan Cruver

  I am recsending the previous post in case it did not get through to some =
due to a suspected virus (my system did not pick up anything after virus ch=
ecking). I will not send the attachment though.
    Dear Elaine etc,
    I searched the net re reproduction times for Nematodes, I found the fol=
lowing.
    http://edis.ifas.ufl.edu/LH053 Life Cycle and Reproduction
    Plant parasitic nematodes have a fairly simple life cycle which has six=
 stages: the egg, four juvenile stages, and adult. Inside the egg, the embr=
yo develops into the first stage juvenile. The first stage juvenile molts i=
nside the eggshell to become a second-stage juvenile, which hatches from th=
e egg, and in most species, must feed before continuing to develop. The nem=
atode molts three more times to become a fully developed adult.
    The length of the life cycle varies considerably with each species, its=
 host plant, and the temperature of its habitat. Rates of activity, growth,=
 and reproduction increase as soil temperature rises, from about 50°F (10=
°C) to about 90°F (32°C). Minimum generation time is about 4 weeks fo=
r many nematodes under optimum conditions (about 81°F or 27°C for many =
nematodes).

    The number of eggs deposited by a female varies among species and is af=
fected by the habitat. Most species produce between 50 and 500 eggs, but a =
few sometimes produce several thousand eggs per female. Eggs of some specie=
s can survive without hatching for years but hatch quickly when a host plan=
t grows near them.

    (This is another site with info on nematodes if anyone is interested. h=
ttp://www.marchbiological.com/L/beneficial_nematodes.html)

    My question is what is the reproduction time for the beneficial nematod=
es and will they multiply in the CT?
     In light of the above info it seems unlikely that reproduction time wo=
uld be under 24 hours (the usual CT cycle). Thus it is unlikely that benefi=
cial Nematodes will reproduce in CT?? Thus if you are using large brewers (=
3000litre-600gal, as I am) it would seem unlikely that you would get suffic=
ient numbers of Beneficial Nematodes extracted from the compost if you only=
 use say 50 pounds of compost (containing B Nematodes).
    This will depend on numbers of nematodes in the compost of course and =
how good your extraction is.
    This is of particular interest to me since I have been told that wheat =
fields where we will be using the CT have root feeding Nematodes I would li=
ke to be able to inoculate the field with Predatory Nematodes (as well as F=
ungi Bacteria etc).
    It would seem to me that we will need to make sure we use enough compos=
t in the CT to get the high numbers of Beneficial Nematodes since they will=
 not reproduce in the CT (unlike Fungi which will multiply in the CT)?? Wit=
h the particular system I use it is not a problem to deal with 150kg (sa=
y 300pounds) of compost per batch.
    Thoughts on the matter would be of great help.
    Thanks for your response on the issue of Strike Rust I have contacted B=
ruce Elliot and am waiting for a reply.
    Regards Mike Harvey.
    New Life Soils, West Aus.
    Email mharvey@westnet.com.au




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