What Causes Citrus Yellowing? A Full Analysis of the Causes and Solutions
Yellowing is now a common problem in citrus cultivation, and it gives many fruit growers a splitting headache. It mainly shows up as yellowing and dropping leaves, poor disease resistance and susceptibility to illness in the plant, and low fruit yield and quality, seriously affecting the grower's income. So what causes yellowing? How should it be solved? Come to Qinnong Web for a detailed introduction.
1. Lack of elements
Citrus trees need many kinds of trace elements as they grow, and once a certain element is lacking, yellowing appears. For example, when nitrogen is lacking, the plant's leaves begin to turn yellow and become thinner; when phosphorus is lacking, new leaves grow densely and old leaves turn bronze; when magnesium is lacking, old leaves begin to turn yellow and show triangular yellow patches; when iron is lacking, new leaves begin to turn yellow; when calcium is lacking, the leaf veins begin to turn yellow, and so on. A lack of any element in the plant can cause yellowing.
Solution: Fertilize diligently to ensure the nutrients the plant needs for growth. When fertilizing, pay attention to balanced combinations and to the supply of all kinds of elements. Never apply a single fertilizer only. It is recommended to apply organic fertilizer or a multi-element compound fertilizer.
2. Soil and root causes
Problems with the soil and roots can also cause yellowing in citrus. When soil fertility is poor or the soil is compacted, the roots cannot grow normally or are damaged and cannot absorb nutrients and water, which leads to leaves showing a half-green, half-yellow appearance and, in severe cases, to leaf drop. In addition, root-knot nematodes can cause root nodules, so the roots cannot grow and absorb normally, and this condition also appears.
Control method: Choose a plot with fertile, loose soil for planting. Strengthen management at planting time, fertilize regularly, maintain soil fertility, loosen the soil and weed at set times, increase soil permeability, and use root-knot nematode control agents as a root drench to eliminate the disease.
3. Pests and diseases
Citrus has a great many pests and diseases, with more than four hundred kinds on record, and some of them also cause citrus leaves to yellow. For example, among diseases there is huanglongbing (citrus greening), and among pests there are mites, aphids, longhorn beetles and citrus psyllids, all of which can cause yellowing.
Control method: These pests and diseases cannot be treated all the same way; the specific method must be analyzed case by case, since different pests and diseases require different methods. So you must understand their damage characteristics in order to prescribe the right remedy.
The above is Qinnong Web's presentation of the causes of citrus yellowing and the solutions. That is all for the introduction to the problem of citrus yellowing. The editor has also provided solutions for various causes, hoping it can help you. For more agricultural knowledge, please keep following Qinnong Web.