fall of orange fruit
The oranges become yellow and size diameter is 3 to 4 cm. The fall rate is very high. Starting 1,000 fruit but now 400. The age of tree is 10 years. Please suggest about fertilizer.
Fertilizer is the last aspect of plant maintenance that you need to consider. Several things are more important, such as soil, light, and water. After you make sure these factors are optimum, you might decide to change your fertilizer. Also 1000 fruits on a tree sounds like an awful lot. It would be natural for the tree to drop a lot of extra fruit, and keep only what it can support. This article discusses the basic aspects to orange care: https://www.gardeningknowhow.com/edible/fruits/oranges/growing-an-orange-tree.htm