Potassium Permanganate for White Curl Grubs in potted citrus

A forum for problem solving and exchanging ideas and knowledge related to the edible garden. Now includes sub-forum for sharing recipes and other ideas for using produce.

Moderators: Forum_mod, Pam, jack, Sam, Luzy

Potassium Permanganate for White Curl Grubs in potted citrus

Postby GP » Sun Aug 24, 2014 6:33 pm

G'day all.

I have three citrus in half wine barrels; a Tahitian lime, Kaffir lime and Eureka lemon.

The limes are fine, and all three trees have been fed quite well, but for the past 3-4 months the lemon has been looking sick. The leaves had mostly fallen off, and now it has many flowers and buds, but apart from that it is mostly bare.

Image

I wondered whether it had become root bound (it has only been in the barrel for about 12 months), so yesterday I moved some of the potting mix to check.

I found that it was not root bound, but there were many white curl grubs in the soil. After madly searching many online forums last night, I decided on mixing some Potassium Permanganate (Condy's Crystals) in a watering can and pouring it through the soil.

I used about a half teaspoon in a 10 litre watering can, and did it twice over.

I was wondering how quickly this solution kills the bugs. The impression I got from my reading last night was that it was pretty fast, but I checked the soil this afternoon about five hours after I used the crystals and found that the grubs were still alive.

Does anyone know if this is supposed to be a 'death on contact' type fix, or does it take a little while?

I was also wondering whether I needed a stronger solution.

Thanks heaps in advance.

Greg
User avatar
GP
Propagator
 
Posts: 27
Joined: Mon Aug 06, 2007 9:40 am
Location: Perth

Re: Potassium Permanganate for White Curl Grubs in potted ci

Postby tam » Sun Aug 24, 2014 7:05 pm

Greg I have just been through this with pots I wanted to plant into.
I ended up soaking mine for 2 days as I found they were still alive after 1 day of soaking. The soil in these pots was completely covered with water.
This may be a problem for you as my pots were not as big.
The only other thing you can do is try a systemic spray like Confidor. I sprayed my plants as wellThis will kill bees so do it late afternoon when bees have gone. Maybe throw a net over it for a couple of days.
I would probably do all of them as they could be in the other pots as well.
User avatar
tam
Gardening Sage
 
Posts: 1134
Joined: Sun Nov 13, 2005 3:26 pm
Location: Burpengary Qld

Re: Potassium Permanganate for White Curl Grubs in potted ci

Postby GP » Sun Aug 24, 2014 7:44 pm

Tam

Thanks for the info. I could plug the hole in the bottom of the wine barrel and flood them, but I'm not sure two days in a swimming pool will be appreciated by the plant.

I'd be curious to know how someone has gone using the potassium permanganate method.
User avatar
GP
Propagator
 
Posts: 27
Joined: Mon Aug 06, 2007 9:40 am
Location: Perth

Re: Potassium Permanganate for White Curl Grubs in potted ci

Postby GP » Sun Aug 24, 2014 8:13 pm

Whilst I think of it, I've also noticed that as the water comes out the bottom of the pot it is no longer purple.

I presume this means the potassium permanganate is coming out of the water in the soil.

Is this good/does it tell me anything about the pH of the soil?
User avatar
GP
Propagator
 
Posts: 27
Joined: Mon Aug 06, 2007 9:40 am
Location: Perth

Re: Potassium Permanganate for White Curl Grubs in potted ci

Postby Pam » Mon Aug 25, 2014 6:09 am

The active ingredient in Confidor has been banned in many European countries BECAUSE it kills bees. With it being systemic, the toxins are going to remain in the plant regardless of the time of day that you use it, Tam.

I've heard of some people having success with curl grubs using ant powder, Greg, but haven't tried it myself.
User avatar
Pam
Garden Wizard
 
Posts: 14418
Joined: Sat Mar 22, 2003 1:06 pm
Location: Bundaberg, Qld

Re: Potassium Permanganate for White Curl Grubs in potted ci

Postby tam » Mon Aug 25, 2014 7:52 pm

Would the pollen on flowers that come out after spraying kill the bees Pam.
User avatar
tam
Gardening Sage
 
Posts: 1134
Joined: Sun Nov 13, 2005 3:26 pm
Location: Burpengary Qld

Re: Potassium Permanganate for White Curl Grubs in potted ci

Postby Pam » Tue Aug 26, 2014 5:32 am

Aparently that's the case, Tam. :(
User avatar
Pam
Garden Wizard
 
Posts: 14418
Joined: Sat Mar 22, 2003 1:06 pm
Location: Bundaberg, Qld


Return to Fruit and Produce

Who is online

Users browsing this forum: No registered users and 1 guest

cron