Nutrient Deficiency Induces Branch and Shoot Dieback in Robusta Coffee

Abstract

In southern Sumatra, Robusta coffee is grown mainly in mountain regions, undulating and steep lands, and marginal soils. Management of soil nutrients is a key issue to maintain sustainable coffee production. This survey was conducted at the field of Farmer Training Center (FTC), at Pulau Panggung Village, Semendo Darat Laut Sub-district, Muara Enim District of South Sumatra Province, Indonesia. The trees of seven coffee clones were randomly sampled. The soil of 0-20 cm depth and full-grown leaves from middle branches was compositely sampled. The results of soil analysis and visual symptoms showed a deficiency of macro nutrient including N, P, K, and Mg that coincident with a high incidence of dieback symptoms. We observed that branch dieback incidence was 62-100% with severity score 1.0-2.5 and shoots dieback incidence was 15-50% with severity score 1.0-3.0. Local coffee clone showed a better tolerance on branch and shoots dieback and higher yield potential based on number of fruits and pinhead fruit per bunch. The results of observation on leaf symptoms of nutrient deficiency, slow plant growth, dieback incidence, plant death, and low plant population showed as a failure of coffee establishment induced by low soil fertility and poor plant management.