Phenological characterization of flowering and early berry development of four coffee (Coffea sp.) species in the Philippines

This research is among the efforts of our group to elucidate the physio-morphological complexity of floral bud initiation and early berry growth of four coffee species (Robusta, Arabica, Excelsa, and Liberica) in the Philippines. In the study, the BBCH (Biologischo Bundesantalt, Bundessortenamt and Chimische Industrie, Germany) scale was used to quantify coffee morpho-developmental changes, independent of variation in timing, from bud emergence stage to early berry stage. The scale makes use of two-digit scoring system, where the first digit corresponds to a principal stage (0-9), and the second digit corresponds to a secondary stage (0-9). For each species, five plagiotrophic branches with emerging floral buds (BBCH score=51) were tagged in November 2015 at the Crop Science Cluster, College of Agriculture, UP [University of the Philippines] Los Ba├▒os. These buds were periodically monitored using the BBCH scale until the attainment of early berry growth stage (BBCH score approx 73). BBCH scores will be correlated with available agro-climatic data to establish the genotype-environment interaction on coffee floral bud emergence and development. Preliminary results show that there are variations across species in the pattern of floral bud and early berry growth and development, and that the duration of phenophases is strongly influenced by prevailing agro-climatic conditions. Regardless of species, coffee berries assume the sigmoidal growth curve as shown by the gradual transition from floral bud to early berry growth stages. While all floral buds passed through a dormant phase (BBCH score=57), it appears that release from bud dormancy as affected by agro-climatic conditions, varies across species. More conclusive descriptions will be asserted once the target phenophase are reached, agro-meteorological data collated, and correlation analysis completed before the end of 2nd quarter of 2016.