Hi, i have recently bought a lemon tree, it was bashed around a bit in shipping so i had a good few broken branches but now seems to be ok with some more new growth starting, and seems to be ok now..... but i have only had it about a week so still plenty of time for it to die!, i have other citrus plants, but never had a problem with pests as there all indoors, the new lemon is close on 7 foot so has been grown outside and is not so pest free! I have been checking it over and looking closely, theres a few leaves with a mould like growth on them, its hard to see as theres so many leaves, ive been going through the leaves over the last week and washing it off, most is dry and just rubs off (but i am washing it off with a detergent spray), some is sticky in a few places underneath, but all is just the same mouldy dust or sticky, cant see any insect , one leaf on the tree had a web accross between the leaf and a cacoon shell underneath the web about 3/8 inch long about 3/32 inch in diamiter , there was no sign of any insect and no more cacoons Im guessing its either scale or aphids, i cant see any aphids til today when there were about 2 on the whole tree , so i cant see it being that, i cant see anything that would be scale (but have never seen it!) so i am wondering if it is just a mould? Has anyone got any ideas about wether its just a mould or wether its got any scale on it? Ive been washing with weak detergent spray, would it be worth spraying with copper/lime spray , or with something like neam oil just in case?
The mold is called Sooty Mold. Sooty Mold is not very hazardous to your tree, other than reducing a little photosynthetic activity. However, sooty mold, is a result of an insect problem, probably scale. Scale, aphids, mealy bugs, and white fly, all deposit a sticky excretions on the leaves. It is this sticky excretion that sooty mold feeds on. Eradicate the insects, and the sooty mold will stop. The middle picture is not very clear, but I think I see scale along the mid vein, and leaf margins. Scale looks like tiny small and flat scabs. They should be easily see with the unaided eye. Look on the top and bottom of the leaves especially along the leaf vein. Scale can be controlled by horticultural oils, or soapy water solutions. Take care and good hunting. - Millet
thanks, Ive just been looking very carefully and on a few leaves i had a flat brown mark, about 1/16 inch in diam, felt perfectly flat not raised much, like it was a light brown tar spot, if i flick with my fingernail i managed to flick them off, i also found another cacoon and got a photo, it was empty again, no sign of anything living this was on a part i hadnt looked at so probably had been there before i got it, i have a photo of the cacoon, not of the little brown flake
