It has since been treated successfully, but the leaves are getting more yellow and.

Jan 21, Nitrogen deficiency - shows as yellowing of older leaves in the tree's foliage. You can add special nitrogen-boosted fertiliser in your feeding to help resolve it. Zinc or iron deficiency - shows as yellowing of new leaves with green veins. To fix this, use a Estimated Reading Time: 5 mins. Nitrogen deficiency is one of the main causes of yellow leaves on a citrus tree.

Nitrogen is a nutrient used in almost every process of life for citrus and fruit trees, from growth to the production of fruit. A lack of nitrogen in the soil will affect the tree's health, beginning with the leaves.

Jul 17, It is not uncommon for citrus trees to naturally drop a small number of leaves especially in winter. Where a large proportion of leaves fall it is a sign that the plant is under stress and there are a number of possible causes. Low light levels area common reason for leaf drop. Both are more prevalent on young leaves of the fall growth flush as soils cool and root activity diminishes.

Potassium deficiency. Identification tip: Yellowish leaves with edges bent downward, especially at tip are symptomatic of insufficient potassium. Phytotoxicity from oil and copper. Apr 22, A number of pests may also be responsible for lemon tree leaf drop. Asian citrus psyllid produces honeydew, which leads to sooty mold as well as causing damage and leaf drop due to the feeding on of the young citrus leaves.

Oil sprays can control this pest when applied frequently. Citrus leaf miners are also an intrepid pest assailing lemon tree leaves. Barely noticeable to the naked eye.