Nurdin Sitohang, Erwin M. Harahap, Chairani Hanum, Tumpal H.S. Siregar, Hasril Siregar
Hard pruning on cocoa trees needs to be followed by fertilizing and maintaining them in order to get the expected development of leaves, flowers, fruits and production. The objective of the research was to determine the right time for applying the best fertilization for the pruned TSH 858 clone cocoa. The research used non-factorial group random design with the application time treatment of N.P.K.Ca.Mg 12,9 : 11,4 : 16,8 : 10,6 : 4,8 fertilizers at the dosage of 1.120,1 grams per tree. They consisted of 4 stages: (1) without applying fertilizers as control, (2) applying them 2 weeks before pruning,( 3) applying and pruning simultaneously, and (4) applying once in 2 weeks after pruning. The parameter of flush, leaf size, the number of water shoots, flowers, cherelles, and pods were observed in 24 weeks. The time for applying fertilization with pruning has significance influence on the number of flowers and cherelles. Pruning with fertilization increases the forming of better flushes and increases leaf size. Application of fertilization in 2 weeks after pruning indicates the best result with 691 flowers, 56.7 cherelles, and 31.5 pods. Fertilization after pruning should be done to increase the number of flowers and pods. © 2019 IOP Publishing Ltd. All rights reserved.
Doctoral Program Agricultural Science, Faculty of Agriculture, Universitas Sumatera Utara, Padang-Bulan, Medan, 20155, Indonesia; Program Study of Agrotechnology, Faculty of Agriculture, Universitas Sumatera Utara, Padang-Bulan, Medan, 20155, Indonesia; Sungei Putih Research Center, Sungei Putih-Galang Sumatera Utara, P.O.Box 1415, Medan, 20001, Indonesia; Indonesian Oil Palm Research Institute, Jl. Brigjen Katamso No.51, Medan, 20158, Indonesia; Program Study of Agrotechnology, Faculty of Agriculture, Universitas Katolik Santo Thomas, Jl. Setia Budi No.479-F, Medan, 20132, Indonesia