There seems to be fungi that has developed on the surface of my lime plant. I have tried spraying a solution of diluted hydrogen peroxide to kill the fungi but it has not helped much. Is there anyway I can remove it completely?
The photo is oddly not in focus at critical spots and I can't see the problem.... not really sure if I'm seeing fungal infection.
The blurred areas -- without being at all distinct -- are making me think I'm seeing scale insects. Ha. It would be almost unbelievable if this is actually the case, but I thought I would mention it, just in case.
...since you are using such sandy media, be sure to start giving them Citrus fertilizer -- scratch some along the perimeter of the pot (away from the plants) with a plastic fork(watch out for the roots). Alternatively, put a spoonful in quart of water, dilute --cut in 1/2 at least-- and water with it.
Agree, not clear that there is a fungal infection. If you post another picture, please do it when there's not water drops on the leaves; that makes it even harder for us to know what is what.
It looks like scale. For a small plant you can use a cotton swab or a sponge and alcohol and rub them off. Citrus likes well drained soil, but in a pot you will need to water it more often if it does not contain a lot of organic matter to hold on to water. I use citrus food vigoro 6-4-6 and osmocote for most of my potted plants. The package will tell you how often and how much to apply. Tree fertilizers are based on the diameter of the trunk so the amount varies depending on the age, stage of growth, and diameter.
When the new leaves come out citrus are often attacked by scale, aphids and whiteflies so you do have to look under the leaves every week. Put out ant bait at the base of the trees. I use outdoor terro. The bait stays in the container so it does not contaminate the soil. Ants need to be controlled or they will protect aphids, scale, and mealybugs from predators. Asian psyllids and citrus brown aphids can transmit fatal diseases to citrus like Huanglongbing and tristeza.
They look like seedlings. Citrus trees will take 5-7 years to fruit from seed unless they are grafted.
Ok so here is a clearer pic attached. I am referring to the green portion on the surface of the soil (marked in yellow border). Is this fungi or something else?
You could hurry the process a bit by scratching the surface and loosening up the sand with a (plastic) fork -- I love re-using "freebie" plastic utensils from food places.