Dr. Pieter Raath 


Dr. Tarl Berry,

Mr. Vivian White, Ms. Johanè Niemann and Mrs. Jade North.



Research within this programme focuses on the physiology of citrus flowering and optimising fruit set and fruit thinning strategies with specific focus on managing the vegetative/reproductive balance by tree manipulations and the novel and effective use of pre-harvest plant growth regulators (PGRs). The research aims to integrate environmental and horticultural aspects related to citrus tree and fruit physiology to develop effective crop manipulation strategies to ensure consistent production of export fruit.

Another focus is developing long-term research projects to improve water use efficacy in citrus orchards in addition to studying the impact of soil and foliar nutrients on yield and fruit quality. Absorption of applied nutrients on citrus trees can be affected by environmental as well as cultural factors such as cultivar-rootstock combination as well as irrigation practises. Therefore, an understanding of the basic principles involved in citrus tree physiology and integration with a nutrition programme and irrigation scheduling are critical to increase production and fruit quality.