Respons Pertumbuhan Bibit Kopi Arabika (Coffea Arabica L.) Varietas Sigarar Utang dengan Perlakuan berbagai Macam Zat Pengatur Tumbuh dan Tingkat Naungan

Abstract

Productivity of arabica coffee Sigarar utang variety in Indonesia is still relatively low, especially in Simalungun Regency, North Sumatra Province. The low productivity of coffee is partly due to the low quality of coffee seeds used by farmers in coffee cultivation. One of the factors that need to be considered in coffee nurseries is external factors in the form of providing plant growth regulator and shade. This research aims to study the types of plant growth regulators and shade levels that are best for the growth of arabica coffee seedlings. The experiment was carried out from March to June 2022 in Nagori Ujung Bawang, Simalungun regency and the Central Laboratory, Faculty of Agriculture, University of North Sumatra. The experiment used a split plot design consisting of 2 factors and repeated 3 times. The first factor (main plot) consists of 4 levels, namely without shade, 50 shade, 70 shade, and 90% shade, while the second factor (sub-plot) consists of 3 levels, namely auxin growth regulator, cytokinin, and combination of auxin with cytokinin. The results showed that the interaction of shade treatment and growth regulators had a significant effect on leaf length, leaf width, root length, root volume, canopy dry weight, root dry weight, root and canopy ratio, and leaf protein content. The 90% shade treatment showed the best results on the parameters of seed height, leaf area, root volume, root canopy ratio, and total leaf chlorophyll content. The effect of the best growth regulators on the growth of coffee seedlings was shown in the cytokinin treatment, namely leaf length, leaf width, leaf thickness, and leaf protein content, as well as in the auxin and cytokinin combination treatment, namely root length, root volume, shoot dry weight, and shoot ratio. root.