Genetic Variation among Robusta Coffee Genotypes for Growth and Yield Traits in Ghana

Quantifying the level of variation and estimates of genetic parameters are important to make informed decisions regarding the improvement of agronomic traits in Coffea canephora. The objectives of the present study were to assess the growth and yield performance of 54 C. canephora clones derived through ortet selection, based on yield from a previous hybrid trial; estimate genetic parameters of growth traits (stem diameter, height, span, number of laterals, length of laterals and diameter of laterals), and yield; and determine the relationship between yield and the growth traits. The clones were planted in the field in 2009 using a randomized complete-block design with three replications. Significant (p < 0.01) clone effects for all traits and broadsense heritability range of 0.15 (mean yield of last 3 productive years)-0.43 (diameter of laterals) were observed. Stem diameter was moderately and positively correlated with early years’ yield (2012/13 mean yield, r = 0.49; p < 0.001), late years’ yield (2014 to 2016 mean yield, r = 0.44; p < 0.001), and mean yield across five years (r = 0.42; p = 0.001). Relatively high genotypic coefficient of variation and expected genetic advance values were obtained for the evaluated traits, which indicated a high probability of success of selection for these traits.