(It is 30 years old)
Here are some tips https://www.gardeningknowhow.com/edible/fruits/avocado/avocado-tree-with-no-fruit.htm
Hi there, here is a link to a wonderful site with lots of information on getting your avocado to flower.
is it not flowering at all or not producing fruit from the flowers(not getting fruit from flowers no pollination/bees) ? Avocado trees normally bear heavily in alternate years, so your tree may just be resting up for the next big crop. The problem could have been any of the environmental factors too extreme conditions too dry soil, too cold,too wet,too hot too early(the weather has been different this year).You don't want to keep soil for an avocado tree too wet, especially if your soil is clay, since that can cause root rot, but as spring progresses, pay attention. When soil is dry 3 to 4 inches down, water deeply (meaning, for a long time).
It is possible that the pruning is at fault. Avocado trees are naturally thickly leaved trees, but heavy pruning can result in so much leafy regrowth that the plant doesn't have energy to bear fruit. If the problem persists, discuss it with an arborist. Light pruning in midsummer (not late summer or fall) is less likely to cause vigorous regrowth than spring pruning.A note on avocado pruning:Avocado trees don't need much pruning, but since they can reach 60 feet tall, some try to limit their size while they are still young. It is best done by cutting the tips of branches or just pinching out the terminal buds of upright shoots for a few years. The goal is a shorter, compact form. Because avocado fruits are best harvested by cutting them from the tree, you want to be able to reach them.
https://www.agric.wa.gov.au/spring/growing-avocados-flowering-pollination-and-fruit-set more http://ucavo.ucr.edu/Flowering/Flowering.html interesting https://www.motherjones.com/food/2018/05/enjoy-those-avocados-pistachios-and-oranges-while-you-can-because-they-are-going-away/