Physiology and early growth of introduced robusta coffee clones in wet climate drylands in Bacan, North Maluku

Abstract

Abstract Climate change, such as a prolonged dry season, will greatly determine the physiological processes and growth of robusta coffee. To overcome this, suitable clonal planting and proper fertilization are required. This study aims to determine the physiological properties and early growth for the suitability of climatic conditions and cultivation treatments. The study was conducted in Latosol soil in the dry land of IP2TP (Instalasi Penelitian dan Pengkajian Teknologi Pertanian) Bacan South Halmahera, North Maluku, from September 2018 to November 2020. The study was arranged in a factorial randomized block design with three replications. The first factor consists of clones of coffee consisting of five clones, namely: BP42, BP409, BP936, BP93 and SA237. The second factor is the fertilizer dosage which consists of 3 levels, namely: (1) 100% chemical NPK (120kg ha−1), (2) 50% chemical NPK + 50% organic and (3) 100% organic. The results showed that the chlorophyll and proline content of leaf was determined by the interaction of clones and fertilization. 50% organic fertilization produced the highest leaf chlorophyll content in clones BP409 and BP936. 50% organic fertilization also produced the lowest leaf proline in clone BP42 which showed more tolerance to drought. Agronomic traits such as plant height are determined by the type of clone. The plant height of BP409 clone highest was significantly different from BP42 and BP936.