I got this small grafted Gold Nugget mandarin last November. It was kept indoor in a grow tent with LED light (mix of 5000K and 3000K). It put out some new growth, but last month I started to notice there are some cracks and dry sap on stem, leaves also have some bumps. Is this some kind of disease or insect problem? My other citrus does not have these problem (pink lemon, kumquat, valencia orange…etc). It is feed with foliage pro every time I water.
Does this plant have some type of nutrient deficiency?
From my knowledge sap is an indecator of scale. Especially if it’s in the house. Wish I could help you more. I recently had it on my calamondin and grapefruit. It was sucking out the life. Check under the leaves, stems and trunk.
Thank you. Now I look closer, I do see the little light yellow dot on some of leaves and they can be remove by finger nail. I gave the plant a good through spray of Clarified Hydrophobic Extract of Neem Oil. Also hand remove these little dot.
I don’t think it’s CLM, but more likely scale of some sort. Neem will work, and you can actually combine both Neem and Spinosad (mix separately, then combine into your sprayer), and you should have coverage for about anything that could infect an indoor citrus. CLM is not active right now, especially in your area. I do not see any leaf tunneling that would indicate past CLM infection from last spring/summer.
It is in nurseries and this would be the time to notice initial damage from penetration. However – if what I thought were internal bumps are actually surface “bugs” then I agree that it is not CLM.
I like the idea of combining Spinosad with Clarified Neam as the latter is solely a surfactant – it can be effective on juveniles but has a poor track record on adults.
It will, and for CLM, the combination of Neem and Spinosad is what Clausen Nursery uses for its citrus very successfully. But, I agree, the bumps look like baby scale to me.
I would spray right now, then follow the guidelines on the labels. Scale and spider mites are the two most common pests affecting indoor citrus. I don’t raise indoor citrus myself, as I’m in a citrus growing zone, so all my citrus are outside. Hopefully, our more experienced indoor citrus growers will chime in.
That is scale. I get it when my citrus comes indoors for the winter. I keep a small 1 qt. spray bottle of water with one teaspoon of triazicide mixed into it. I spray all of the citrus, on top and underneath the leaves, and stems. The scale dries out and drops off. Done! Really works! Also spray the soi/gritty mix.
