Have you noticed white spots on lemon tree leaves? Are these interesting signs a sign of disease or infestation? How do they affect the health of your tree and what effect will they have on the harvest? Isn’t it reassuring to know that natural solutions exist to protect your lemon tree and restore its vigor and luster?
What causes white spots on lemon tree leaves?
This unpleasant phenomenon can be attributed to many reasons and unfortunately, it is becoming more and more common. In any case, it is important to identify what is causing the damage to your tree, so that you can take immediate action. Of course, preventive actions are also important, as they can save you from drama. So, without further ado, let’s find out what causes white spots to appear on citrus fruits:
Powdery mildew or lemon powder
It is a fungal disease that appears as a white, powdery coating on leaves, stems and sometimes fruits. It looks like flour or white fluff. Powdery mildew often grows in areas (or rooms) where heat is moderate and humidity is high.
mealybug
Here we are talking about an infestation of tiny insects that gather on leaves and stems, secreting a white waxy substance to protect themselves. They can weaken the plant by sucking its sap, causing stunted growth and yellowing of leaves.
Water stress
Inadequate watering, whether too much or too little, can create imbalances in plants, sometimes resulting in white spots due to mineral salt deposits in leaf tissue or physiological disorders.
Chemical burns
Improper use of pesticides, fungicides or other chemicals can cause leaf burn or discoloration, which may appear as white spots. Therefore, never use concentrated products, even if they are of natural origin.
Nutritional deficiencies
A deficiency of certain essential nutrients such as magnesium or zinc can lead to leaf chlorosis, where the center of the veins turns yellow or white, while the veins remain green. This contrast may seem striking, but it is definitely a sign that something is wrong with your plant. Please also note that this problem is often related to drinking water. In other words, if the soil is dry or wet, the roots cannot absorb the nutrients. So adding fertilizer will not solve the problem.
Sun damage
Excessive exposure to direct sunlight, especially after watering in daylight, can cause sunburn. In this case, you will see discoloration of certain areas on the leaf. It is also not excluded to find brown leaves.
Once the cause is found, treat the leaves with one of the following methods:
- Lemon powdery mildew : There are two options available to you. For the first, mix 1 teaspoon of baking soda in 1 quart of water and add a drop of dishwashing liquid to help the liquid stick to the leaves. Then spray the affected parts. For another, you’ll need sulfur. Only spray the plants, but not when the temperature exceeds 30 degrees Celsius. This can be effective, but be careful not to overdose.
- mealybug : Mix liquid black soap with water and spray directly on insects. Repeat regularly until they disappear. Neem oil is also popular and often used as a natural insecticide because it interrupts the mealybug life cycle.
- Chemical burns : If you suspect a chemical burn, rinse the leaves with plenty of water and remove the residue.
Preventive measures
A citrus garden is a dream! So, master the maintenance of lemon, orange, kumquat tree, etc. Follow these simple tips:
- In a pot or in the ground, learn how to regulate tree watering based on weather conditions. As a general rule, the top layer should be watered as soon as it feels dry to the touch. This can be once a week in winter or three times in summer. But to determine this, just check the soil. Additionally, it is advisable to apply a layer of mulch to retain water in the soil.
- Avoid using chemicals. There are many natural solutions that can help you fight pests.
- When it is very hot, put an umbrella, for example, to protect it from the sun’s rays.
If you see white spots on the leaves, this could also be due to high levels of calcium and magnesium in the water. Keep in mind that you need to water the plant with fresh water to keep it healthy. Otherwise, you risk changing the pH of the soil and damaging it.
