Yellow splotches on Kumquat leaves

[Larry Zavadil]

The leaves on my kumquat have yellow splotches.  New and old leaves.  They don't fall or die, just have splotches.  Deficiency?  Bug?  See picture.

[Susanne42]

could be manganese deficiency?
What fertilizer do you use?

[Millet]

As Susanne wrote it is probably a manganese deficiency.  A manganese deficiency shows on the newest leaves having green veins WITH green border areas to the side of the veins, on an otherwise yellow leaf.  Manganese deficient leaves remain NORMAL SIZE. Manganese deficiency commonly shows up when the tree is flushing new growth, but not always.  I can't see your picture all that well, so I will also mention it might be a zinc deficiency.  A zinc deficiency looks very much like a manganese deficiency --- green veins with a green border area to the side of the veins, and also showing on the newest leaves, but in a zinc deficient leaf the leaves are substantially dwarfed in size.  You can foliage spray with  a dilute solution, or apply the fertilizers to the root zone, using manganese sulfate or manganese nitrate to correct the manganese deficiency.  The same procedures using zinc sulfate should take care of a zinc deficiency.

[Mike T]

Could be manganese, zinc, magnesium or a combination of deficiency symptoms showing. Causes can be over application of specific fertilisers or just a lack of that nutrient. Manganese and Zn should be applied together to avoid antagonistic effects which could worsen the situation. Quite often too much of one  nutrient causes deficiency in another hence antagonism.