Changes in the respiration and growth rates of developing fruits ofCoffea arabicaL.

SummaryThe rate of dark respiration, at 30 °C, of newly-detached developing coffee fruits, fruit pericarps and seeds is described in relation to their increase in size and dry weight (d.w.). The fruits took up 2 ml O2/g d.w./hr when they started to swell 6–8 weeks after flowering. Between 9 and 17 weeks the fruits expanded rapidly, seed endosperms were formed, and individual fruit d.w. increased to about 200 mg. Oxygen uptake per gram d.w. decreased to 0.5 ml 02/hr, while uptake per fruit increased to about 90μl O2/hr. From 17 weeks after flowering until ripening, at about 30 weeks, the fruits swelled relatively little but increased in d.w. to about 500 mg. Although the respiratory activity of the pericarp and seed tissues decreased greatly, oxygen uptake per fruit remained unchanged (about 90 μl O2/hr). During and after fruit ripening the pericarp increased in size and d.w. and respired more rapidly than before.Changes in the carbohydrate demands of developing coffee fruits are discussed.