A mature avocado tree may produce in excess of a million flowers during the flowering period, most of which fall without producing fruit. One of the factors leading to flower fall is proper pollination not taking place.
Bees are the world's dominant pollinators. Within orchards they play a vital role in the pollination of the fruit trees. Without them yields might not be economically viable. Therefore, there is a need to protect and ensure the preservation of these important environmental components.
Without honeybees and cross-pollination, a mass majority of fruits would not be available.
Well, the overall goal of cross-pollination is to ensure that the pollen from the stamen in one flower has been transferred to the pistil of another flower. Once the pollen grain has transferred from the stamen to the pistil, the grain germinates and fertilizes the ovule developing a seed. Bees play an imperative role in this process as they are carriers of the pollen.
http://oxfarm.co.ke/agri_biz-insights/avoid-shortcuts-make-the-best-orchard/
Besides the farmer benefiting from effective pollination taking place also bees make honey and here are some of the health benefits associated with eating pure honey.