Hi everyone, I am a new citrus admirer and my first tree was a dwarf Persian lime which I lost to scale infestation. This tree was a root growth of the main tree (I believe) similar to the little growth in the pot now. I'm not sure if this is the rootstock plant or not but I have decided to keep it. Everything was going well until a month ago when the new growth was accompanied by leaking clear and tasteless sap from every new emerging branch! The tree is dying back now. I couldn't find any insects on the tree. There are swellings on the new branches but nothing under them. Any ideas what this might be? Thank you!
I have never personally seen it, but it is possible you may have a copper deficiency. That is documented to cause sap leakage in a way that looks similar to your photos, for example here: https://app.periodikos.com.br/article/10.4322/crt.ICC067/pdf/citrusrt-38-1-99.pdf Another possibility is a fungal infection, e.g. phytophthora gummosis, but your photos do not look quite right for that based on the literature I have seen. Info on gummosis available here: Fact Sheet: Phytophthora | Citrus Diseases Another possibility is past damage that has not yet sealed and is leaking a bit. My guess based on the photos would be copper deficiency. Have you used a fertilizer with micronutrients? For example, Miracle Grow has a tiny amount of copper which is all that is usually needed to avoid copper deficiency.
I've seen a few of these some time ago on my 'Variegated Pink' lemon. It turned out to be nothing to worry about. It's probably something similar to 'grape pearls': Grape Pearls - Weird sap on the vine | Horticulture and Home Pest News. However the leaves do not appear to be healthy, perhaps due to some sort of nutrient deficiency.
Thank you very much for your replies! I haven't fertilized yet since I was worried this might be a fungal disease or an insect. But I will go ahead and fertilize with copper containing fertilizer and hope for recovery. On another note, the first tree this one came from as one of those small growths was a dwarf Persian lime so I am assuming it is a rootstock, but it looks completely like the main tree that died. Is it foolish to think that this one will ever produce lime? Thanks a ton!