Are my orange tree's yellowing leaves a sign of underwatering?

Question

I have a mature orange tree in my back yard and I've noticed that the lower leaves at the extremity of have started to to yellow over the last couple of months.

Is this a sign of overwatering? Underwatering? A lack of necessary nutrients? Something else?

Answer 1

A picture would help. You can do the diagnosis by doing a walk around the tree. Check for these items:

• is the soil compacted and dry or springy and rich with organic matter?
• is there competition from grass and other plants under the tree
• are the veins of the leaves green and the rest of the leaf yellow (nutrient deficiency)
• is the soil dry and sandy or clay? Does it drain well or does water puddle on the surface?
• any signs of insect issues? Scale gives a sticky sugar on branches and on the ground. Mealy bug looks like white fluffy clumps in the axils of the branches
• do you water the plant? Is the local water high in salt content?

Let us know and we do more diagnosis.