Whiteflies and worm castings

[duajones]

Read recently that mulching with worm castings has shown to repel whitflies and wondered if anyone here has experience with it. Here is a little what I read:

An exciting development in a new form of whitefly control may be coming to light. Studies conducted over a six-year period show that plants mulched with worm castings repel a variety of pests, including whiteflies. Apparently the worm castings raise the level of a particular enzyme in the plants-the enzyme chitinase-which whiteflies find distasteful enough to keep moving. The recommendation is to spread a one-inch layer of worm castings around the plant and periodically apply more. It takes some time for the enzyme to form.
In an article published in May 2000, Los Angeles Times reporter Julie Bawden Davis noticed a significant drop in whitefly populations one month after mulching a whitefly-infested hibiscus. After seven weeks, she said, there were absolutely no whiteflies on the plant

[mtbigfish]

Dua
I used to get white flies a lot and that terrible white sticky stuff on the leaves - not because of that but just for plant overall health I have been spreading a cup of worm castings on top with my mulch and now that you mention it I haven'y noticed them as much for the last 3-4 years

only problem is I just picked up a 20 lb bag from the local farm supply and the cost skyrocketed from $25 to $35 a bag
Wow
Dennis

[duajones]

I was quoted 14.99 for a 15 lb bag by the first place I called. I incorporated worm castings in the hole of my plants in 07 and 08 and didnt have the whitefly problem I had in 09. But I have no idea if the castings had anything to do with it.

Apparently the worm castings raise the level of a particular enzyme in the plants-the enzyme chitinase-which whiteflies find distasteful enough to keep moving. The recommendation is to spread a one-inch layer of worm castings around the plant and periodically apply more. It takes some time for the enzyme to form

edit to add: this study was done on roses not tomato plants but was supposedly effective on hibiscus as well

[mtbigfish]

yeah it's a special brand - really pure

[duajones]

A brand was mentioned but nothing was written about it being specific to a certain brand. Not that I read anyway

[mtbigfish]

Dua
I didn't mention name but I use Agrowinn organic pure worm castings - 99% pure and tested - it has no fillers etc - it has always been 30% more than other brands particularly vermi-composts - sorry too it's 40lbs bag
Dennis

[Blueaussi]

Yippee!

Something organic to try!

And the fellow in the SC Market Bulletin has dropped his price to $0.75 a pound. Thanks Duane!

[dice]

I like dropping in a handful under a seedling when transplanting
into the garden or a container, just for the fertilizer value and
the fact that it is such a natural plant food. (I have never seen
a plant object to earthworm castings or earthworm casting tea.)

I wonder if using earthworm casting tea would work. No way
do I have enough earthworm castings from my little worm bin
to mulch everything an inch deep with it, but I have enough
to make tea and give all of the tomato plants a nice soil drench
with it occasionally. I do not have chronic whitefly problems
up here in Western Washington, but high chitinase levels in
the plant probably repels many other kinds of insect pests
as well. It should help prevent transmission of insect carried
viruses and viroids from local weeds to tomato plants.

I am mixing some into the potting mix that I use for potting
up into newspaper pots this year, so that may raise chitinase
levels in the seedlings at transplant time.

[sfmathews]

Does using DE in the hole at plant out help to raise the chitinase levels enough to repel whiteflies? It was suggested to me last year to do this. I didn't really have a whitefly problem, but whether it was because of this, I don't know. I have had whiteflies in past years.
Thanks,
Susan


I wonder if using earthworm casting tea would work. No way
do I have enough earthworm castings from my little worm bin
to mulch everything an inch deep with it, but I have enough
to make tea and give all of the tomato plants a nice soil drench
with it occasionally. I do not have chronic whitefly problems
up here in Western Washington, but high chitinase levels in
the plant probably repels many other kinds of insect pests
as well. It should help prevent transmission of insect carried
viruses and viriods from local weeds to tomato plants.

I am mixing some into the potting mix that I use for potting
up into newspaper pots this year, so that may raise chitinase
levels in the seedlings at transplant time.[/quote]

[dice]

[diatomaceous earth and chitinase]

I did a little web searching on this, but did not find
anything mentioning a connection between DE and
chitinase levels in plants. DE is used as a repellent
for certain kinds of insects, but I get the impression
that it works as a physical irritant, as a dessicant,
or as a substrate for other substances that do the
actual work.

There is some mention of both bacteria that produce
chitinase and DE used for controlling fire ants. It is
possible that DE in the soil might raise populations
of such bacteria, just as crab shell meal and shrimp
shell meal are said to do for controlling root knot
nematodes with increased chitinase levels in the soil.
But in this case (fire-ant and harmful nematode control)
it is not the plant producing the chitinase, rather it is
some other soil organism feeding on the chitin-containing
soil amendment.

So I would not expect DE in the soil to have any effect on
whitefly infestations of the plant above. (Probably good for
reducing populations of fire-ants and root knot nematodes,
though, if you have those.)

[sfmathews]

Thanks, Dice. I found it hard to believe that the plant could uptake enough chitin to have any impact on insects.
Susan


I did a little web searching on this, but did not find
anything mentioning a connection between DE and
chitinase levels in plants. DE is used as a repellent
for certain kinds of insects, but I get the impression
that it works as a physical irritant, as a dessicant,
or as a substrate for other substances that do the
actual work.

There is some mention of both bacteria that produce
chitinase and DE used for controlling fire ants. It is
possible that DE in the soil might raise populations
of such bacteria, just as crab shell meal and shrimp
shell meal are said to do for controlling root knot
nematodes with increased chitinase levels in the soil.
But in this case (fire-ant and harmful nematode control)
it is not the plant producing the chitinase, rather it is
some other soil organism feeding on the chitin-containing
soil amendment.

So I would not expect DE in the soil to have any effect on
whitefly infestations of the plant above. (Probably good for
reducing populations of fire-ants and root knot nematodes,
though, if you have those.)[/quote]

[b54red]

The soil in my raised beds is alive with worms and by mid summer the soil is covered with worm castings and it has made no difference in the whitefly population. As a matter of fact they seem to be worse than years ago when I didn't have nearly as many worms.
I have tried everything to slow down the whitefly population and have found nothing that works for very long. My best results have come from spraying with various things like dormant oil, mild poisons, soaps, essential oils and simple water sprays and alternating them. I only use poisons when the population becomes unmanageable.
If anyone finds something that really works on a heavy population of whiteflies I would love to try it. The last 3 years have been a constant battle from mid July til cool weather arrives in November.

[Blueaussi]

Originally Posted by b54red

The soil in my raised beds is alive with worms and by mid summer the soil is covered with worm castings and it has made no difference in the whitefly population. As a matter of fact they seem to be worse than years ago when I didn't have nearly as many worms.
<...>

LALALALALALA! I CAN'T HEAR YOU! I CAN'T HEAR YOU!



*sigh*



And I was really hoping this would help.

[desertlzbn]

Worse yet, I have whiteflys on my SEEDLINGS URGGGHHHHHHHHHHH Now I have to try to figure out how to not kill my seedlings but kill the whiteflys.

[dice]

[a post in a thread last year on possible TYLCV virus carried by
whiteflies]

Whitefly control is a hard problem:
http://hortipm.tamu.edu/publications/SPWF.html
(Chemical controls require careful timing and the bugs build up
resistance anyway.)

Biological controls for them are not cheap:
http://www.naturescontrol.com/whitefly.html
http://www.arbico-organics.com/organ...y-control.htm

Since they are only seedlings (for desertlzbn), a total
dip in one of the chemical controls might be effective
in the short term.