Fruit thinning with specific reference to citrus species : A review

Fruit thinning is defined as the removal of certain flowers or clusters of flowers or individual fruitlets after fruit set and natural dropping have occurred.it improves fruit yield and quality and return bloom for the following year.There are three types of thinning namely:hand,mechanical and chemical.Chemical thinning is the most common type of thinning.Various chemicals are used for thinning.Still many more are being introduced into the market and they have varying effects on fruit quality and yield,depending on the fruit species and cultivar in question.The effects of these chemicals on fruit set is affected by environmental and ecological factors among other crop factors such as vigour.Alot of research has been conducted or is being conducted on chemical thinning but varied results are generated due to many chemicals being released by the chemical companies and varying farmer situations,yet this topic is of immence interest to chemical companies,researchers ,farmers and the fruit industry.This paper discusses the various factors involved in fruit thinning but mainly the physiological principles behind the process of fruit thinning.A lot of research on thinning has been conducted on Apples and other temperate fruits but not on other fruits such as citrus which has worldwide significance.This review will mainly help pomologists who are conducting research on this area.