Q.Tangerine tree
Every year my tree blossoms but all the blossoms fall off and no fruit.
This could be due to lack of pollination or environmental issues.
Here are some links to help you pinpoint the issue.
https://www.gardeningknowhow.com/edible/fruits/oranges/no-fruit-on-orange-trees.htm
https://www.gardeningknowhow.com/edible/fruits/citrus/citrus-blooming-season.htm
https://www.gardeningknowhow.com/edible/fruits/citrus/fertilizing-citrus-trees-best-practices-for-citrus-fertilizing.htm
https://www.gardeningknowhow.com/edible/fruits/oranges/hand-pollinating-oranges.htm
https://www.gardeningknowhow.com/edible/fruits/oranges/growing-an-orange-tree.htm