I know this is fairly common on citrus, but was just wondering if anybody has some advice please to get rid of the ugly soot. Spray with dishwash liquid over and under leaves? Manually clean each leaf? But basically is there a preventative method I can apply. Plants in question are in pots. Have been wintering under the veranda, they several years old now, healthy and fertilized etc. produce lots of fruit, first year they have had it. Appreciate any helpful advice. Cheers
harm_less,
Sep 7, 1:52pm
The sooty mold is growing on the sugar rich excretions of an insect infestation of the sap sucking variety, probably scale or aphids. To get rid of the sooty mold sort out the insect infestation as if you don't you are destined to failure.
In turn the infestation of insects may well indicate an excess nitrogen supply to the plant so review your fertiliser regime accordingly. Overfertilising potted plants is a common issue.
Once you get rid of the mold's food source (insect poop) the problem should right itself with help from weather or watering.
wine-o-clock,
Sep 7, 2:32pm
spray conqueror oil on it
lythande1,
Sep 7, 2:50pm
Conqueror oil gets rid of the scale (temporarily), which is the cause of the mould. (From the leaking sap). Too clean it, it's pretty much wash the tree. But you can't eliminate it completely. bigger trees cope with it.
beebb3,
Sep 7, 6:50pm
Thanks for the above info, much appreciated. I do spray conquerer oil for the scale, checked today, under, over all round, barely any scale. But, will give them a 'dose' of conquerer tomorrow and maybe in a weeks time. Cheers
trade_menow,
Sep 7, 10:43pm
had that issue 2 years ago . tried weak dishwash spray which seemed to loosen up the soot - then turn around and do it a couple days later which did help somewhat but i spoke to someone in mitre10's garden dept and was told to use mavrik and " keep doing what your doing " 2 weeks later finally got on top of the little sods ( whitefly ) just keep on top of it and it should right it self - my tree did only difference is my trees not in a pot - Good luck
As per my post above the problem comes from infestations of sap sucking insects which includes not only scale (but most common in citrus) but also aphid, whitefly, mealy bug, etc. They tap into the sap flow but consume excess sugars which they excrete as honeydew which promotes sooty mold.
Spraying oil will deal to scale but other problem incests will require something more toxic. Whatever you're using be sure to check on withholding periods to avoid harvesting fruit that is contaminated. Also take care with spraying oils as they can be harmful in sunny/hot conditions as they can restrict plant transpiration.
beebb3,
Sep 8, 9:31pm
Wonderful thankyou all, much appreciated.
clementine4,
Sep 8, 10:54pm
I have the answer and it works! Google "Wallys karbyon citrus sooty mould remover." Use according to directions and then spray with Enspray 99 fungicide. Its organic and safe. Google it. May need to use Karboyn a couple of times. Spray the Karbyon before rain. Wally has an 0800 number. You can ring and talk to him. Problem solved.
tegretol,
Sep 10, 3:35pm
Waterblast (gently) the black stuff off then spray conquer oil and copper sulphase mixed on. The soot will never return.
This stuff is magic! After years and years of trying to get rid of black sooty mould on our lemon and mandarin trees, we have finally found something that works! Amazing product.
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