(Anil Kaushik) wrote:
Thank you for the fruitful information. I think the shape of the
nodules was globular like small beads in a thread. Why I suspect
these to be of Nematodes is because in India dung manure is freely
used as a buffer in making compost and unfortunately it is not
treated or sterilized. The infected plant keeps on growing although
slowly. And in a bid to survive I think the plant struggles and keeps
on throwing new roots. Can Nina correct me on this observation
please?

Hi Anil! You kept me busy. First I tried to find out if members of
the Nyctagineaceae had any nitrogen-fixing symbionts that made root
nodules. A number of plants do, and these nodules are often mistaken
for nematode galls. I found nothing, however. So then I looked
around for information on the nematode susceptibility of more common
plants in the Nyctaginaceae (such as Bougainvillea and Mirabilis; Neea
is rather obscure). I found that neither of those is very
susceptible; a susceptible plant will have "beads on a thread" as you
described, but a less susceptible plant will only have a few scattered
galls. So I have no idea what those swellings are- as someone
suggested, cutting one open and examining it under a dissecting scope
would answer the question in a minute.

As for manu manure would contain one heck of a lot of nematodes,
but not PLANT PATHOGENIC ones. 99% of nematodes are free-living
saprophytes, without whom we would be wading in manure. Very few are
parasites of animals or plants. The plant parasites would not be in
manure, so I wouldn't worry about it. Plant pathogenic nematodes
generally spread VERY SLOWLY in soil, or are transported by farm
machinery in caked mud. Foliar nematodes can be spread by water
splash.

If uncomposted manure had an adverse effect on bonsai, it would be due
to the production of ammonium, which is toxic to plants at high
concentrations.

Nina.