Winter repotting found Grubs again

[Gareth]

any oxidizer will kill fungus, weather pathogenic or symbiotic. depending on strength an oxidizer can "burn" or oxidize anything really, but the thing about oxidizers is it needs to be strong enough to kill and compensate for easier to oxidize substances as well as the organisms you are trying to kill.

For instance, oxidation potential of an oxidizer will first mean that it will oxidize the easier to oxidize particles, this means organics, bacteria and fungus (which it will pretty much destroy on contact), then after all these are oxidized, and if there is any oxidation potential left, it will then go to work on harder to oxidize and kill organisms, the thickness of the cell walls, the size of the organism or particle, and weather or not it has a shell or not (plus a lot of other factors) will depend on not only how much of the oxidizer you need, but also the time the organisms you are trying kill needs to be in contact with it.

Because eggs have a hard shell, and grubs are large organisms it would take more oxidizer to kill it than an organic particle or bacteria.

So essentially you need to compensate for the oxidizer being "chewed up" by easier to oxidize particles to make sure there is enough left over, at a high enough strength to take care of, and cause enough damage to, the grubs, and the eggs that could hatch into grubs.

and just in case i didn't use it enough, here is the word again. OXIDIZE!!!!

gareth

[Jamie]

cheers gareth

so what ya saying it will kill anything good or bad

cheers

[Gareth]

Yes,

But in an inorganic mix there are not many organics so it would be easier to treat any pests, and the oxidizer would not be "chewed up" as fast as it would be in an organic or partly organic mix, and replacing symbiotic bacteria and fungi is easy using compost tea and fertilizers to "reseed" the soil with beneficial organisms.

So really you have to question, what is the lesser of two evils, after all when re potting, you remove all if not all the bacteria and fungi and need to re-establish it nearly from scratch anyway.

Compost tea is great, you pretty much BREW compost in a bucket with aeration, dilute it and use in on your garden, in pots it would be a little different in using it, as it is a more confined environment, but for remediation of soil there is really nothing better.

look at http://www.soilfoodweb.com.au

gareth

[Webos]

http://en.wikipedia.org/wiki/Cockchafer

This is a link to info on curl grubs. Make sure you read about the court case...very interesting.

[63pmp]

Soaking for an hour would not be long enough to kill curl grubs, 24 hours would be better. Any sort of oxidiser, like peroxide, would also oxidise the plants roots, much safer to go with a curlgrub specific poison. In the past I have used a half strength solution of pyrthrum, soaked the plant in it and the grubs come to the surface, they die after an hour or so. Not had so much trouble with them since moving to a mostly inorganic potting mix.

Paul

[Gareth]

it all depends on how long the plant/soil is submerged in the oxidizer, as explained, the size of any organic materail determines how long it will take to oxidize, and how much iother organic material is in the soil.

If you dont overdo it by too much, and water the plant after wards to flush the oxidizer i bilieve it would be fine.

Perhaps a serious a short dips, rather than one long one would progressive oxidize the organics/bacteria etc, and eventually kill the grub and oxidize the eggs, without overdoing it too much, small doses more often may work.

perhaps next time someone has curl grubs they could test this out, on a young tree of course, so as not to accidentally sacrifice good stock.

[Taffy]

Don't really think I'd like to run the risk of damaging any of my trees with that oxidizing stuff. I use a very simple method. I use an insecticide called Lorsban. It's potent stuff - a little goes a very long way. Mix in some instances is less than 1 part to 10,000. The main active ingredient is Chlorpyrifos. The same chemical in ant sand, but a hell of a lot stronger.

I nearly lost a very nice Root over Rock Green Island fig to these mongrels. They'd destroyed about 2/3rd of the roots.

Whenever I dunk my pots, I always put some of this stuff in the water, and I regularly hand water with the mixture as well - I mean I pour it over the pots - and even use it as a spray over the foliage (caterpillars don't like the stuff either). My trees get dosed whether they need it or not.

Bonsaibruce mentioned that a layer of gravel will discourage the beetles from laying eggs. Trust me Bruce - it doesn't work! All my pots - black plastic, styrene and Bonsai pots have a thick layer of gravel on them - I put it on to stop them drying out too quick in the hot sun and to stop the soil mix from floating away when I dunk the pots. It makes no difference to the curl grub population.

Two problems with using Lorsban:

1. It isn't available to the general public - primary producers and commercial use only.

2. It's a known carcinogenic - ALWAYS wear protective gear when handling the stuff.

It's classed as being non-residual, but I myself would never use it on edible produce - only on my trees and other ornamentals.