The Growth of the Coffee Berry

In Kenya the coffee berry stays in the ‘pin-head’stage for approximately 6–8 weeks after flowering. A periodof rapid growth follows which ends when the berry is about 17weeks old. Thereafter, a small loss of fresh weight seems tooccur while the dry weight remains constant for about two weeks.At this stage the beans have attained their final size but drymatter can be as low as 9 per cent. Until the time when ripeningbegins, the fresh weight of the berry increases little whilethe dry weight increases regularly. In this period dry weightis laid down mainly in the beans which attain their final dryweight when the berry is still green. During ripening of theberry (which is in fact ripening of the pulp) the fresh weightof the beans drops slightly due to loss of water. Both freshweight and dry weight of the pulp (including parchment) increaseconsiderably during ripening by approximately 121 per cent.and 106 per cent. respectively.     

The Effect of Soil Moisture, Nitrogen Fertilization and some Meteorological Factors on Stomatal Aperture of Coffea Arabica L.

Stomatal aperture in irrigated and non-irrigated plants of Coffeaarabica L. was studied by measuring the infiltration into theleaf of mixtures of iso-propanol and distilled water. In potexperiments, stomatal aperture proved to be closely relatedto soil moisture content. In the field, the coefficient of thecorrelation between stomatal aperture and soil moisture contentin the 10 ft deep rooted zone was 0.929 (r² = 0.863) in thedry season and 0.773 (r² = 0.598) in a period of intermittentrain. Stomatal aperture was invariably inversely correlatedwith the calculated soil moisture deficits of five irrigationtreatments. Application of nitrogen fertilizer increased stomatalaperture but no explanation can be offered for this effect.Stomatal aperture as measured by this particular method waslinearly correlated with temperature, vapour-pressure deficitand radiation, and also related to the time of day.