Many gardeners and experts recommend removing the first few sets of fruit on young trees. This allows the plant to use its energy to develop strong roots instead of fruit. Once the plant is established, it should be fine.
Soil moisture problems also can cause fruit to drop before it’s ripe. Dec 10, Pests may cause your citrus trees to lose their fruit. Mites and thrips are known pest causes of losing fruit. Insecticides may be needed, depending on the type of infestation your citrus tree. And George, if you left your previous crop on the tree too long, when your mandarin began blooming, again, you can force your tree into an alternate bearing cycle, so pick your fruit when it's ripe.
this may be the cause of your fruit drop. Citrus fruits have a porous, moist, spongy skin and they are full of water. Unripe citrus tends to be dryer to begin with in my experience -- they continue to fill up with water as they ripen and grow on the tree. They can ripen faster if kept with ripe apples and pears, but they also can become moldy if there isn't good air circulation. Jun 04, 4. Check the nutrient levels of your citrus tree. A lack of potash is a common cause of citrus trees dropping fruit before it is ready to eat.
Always prefer a specialized citrus fertilizer over a more general one as the nutrient balance will be right for the tree.