Shrivelled Kumquat Nagami fruit
(Molesworth, Victoria, Australia)
We have four 6-10 year old Kumquat Marami and Kumquat Nagami trees. The Marami trees have small fruit shrivelling up on the tree and many dropping while the Marami has larger distorted fruit and yellowing leaves. Is this a magnesium deficiency?
Thanks for your help.
Hi Cindianne, I'm not an expert in any kind of citrus trees, because they're not hardy where I am.
However, this kind of damage would be fairly typical of a deficiency of some kind.
If it's magnesium, that's easy to fix - apply dolomite lime to the drip line of the tree, and water it in well. It will most likely not have any effect on the tree until next year, as the damage is already showing up with the deformed fruit.
Citrus trees also can be deficient in iron which shows as chlorosis, yellowing foliage with darker green veins, and zinc deficiency shows as yellowish blotch or mottle between leaf veins. Sometimes, this can be caused by excess watering, so check your irrigation practices. The soil should be moist, but well drained. No citrus like to have wet feet.
Other things to try; make sure that there are no pests on the tree by cleaning up fallen leaves, and applying tree tape (double sided tape) to the main truck to prevent ants from carrying their favorite aphids up to the growing tips.
If your soil is extremely droughty, add a mulch to the soil from the drip line to about a foot away from the trunk.
These types of trees prefer being irrigated with a soaker hose or other drip type irrigation rather than overhead sprinklers.
Hope this helps get your Kumquats back into top form,