Optimising growth in relation to light regime and development of "improved robusta" coffee

Abstract

Coffee breeding at the Cocoa Research Institute of Ghana over the past decade has focused on the improvement of the local Robusta coffee which has poor agronomic attributes including low yield. These breeding efforts have resulted in the development of a clonal material which has consistently shown better establishment, faster growth and development and higher yields over the local robusta. The experiment being reported here forms part of a series of trials designed to investigate growth requirements of the improved clonal material so as to maximise its potential. Transplanted seedlings were grown under three levels of artificial shade viz:- 25, 50 and 100 per cent of full-day light (FDL). Shading was provided by slats of bamboo supported on wooden posts. Growth data was recorded at monthly interval. Biomass production under the 50% FDL treatments was significantly greater than the 100% and 25% FDL treatments. Seedlings grown under the 25% and 100% FDL were significantly taller than those grown under the 50% FDL treatment. There were no significant differences in stem girth between the treatments. Root biomass was significantly greater in seedlings grown under the 100 and 50% FDL treatments (differences between the 100 and 50 were not significant) than those of the 25% FDL treatment. The overall picture indicates that a nursing shade of 50% FDL should be provided during establishment of the improved robusta coffee clones. Interplanting with food crops should be managed such that optimum of 50% FDL could reach the coffee canopy.


JOURNAL OF THE GHANA SCIENCE ASSOCIATION Volume 1 Number 1, July (1998) pp. 12-16