Assessment of Arabusta coffee hybrids [Coffea arabica L. X Tetraploid Robusta (Coffea canephora )] for green bean physical properties and cup quality

Robusta coffee is known to be high yielding than Arabica coffee, since it is more vigorous in growth. However, it is limited by the inferior cup quality. The aim of the study was to evaluate the performance of the Arabusta hybrids and its backcross derivatives for bean physical characteristics and organoleptic properties including their interrelationship. Nineteen coffee genotypes were evaluated at Siaya ATC and KALRO-Alupe, using randomized complete block design with three replications. Data on the bean grades and sensory traits was carried out on beans harvested in the year 2018. The results indicated that there was a significant variation on both the sensory and bean grade traits from the two locations. On average, Arabusta hybrids showed better performance on bean traits when compared to its backcrosses and Robusta. There was a highly significant positive correlation between the sensory traits which had highly significant positive association with aftertaste (r=0.96), aroma (r=0.84), balance (r=0.85), flavor (r=0.96) and overall standard (r=0.96).  The positive significant correlation between the 100 bean weight and the AA bean size is an indication that weight of beans can be used in predicting the bean sizes. The interspecific hybridization enables the transfer of good cup quality attributes from Arabica coffee to Robusta coffee.   Key words: Flavor, Arabica, bean grade, quality, Arabica, Robusta, environment, variation.