Development of stem diameter RAP of rubber stand (Hevea brasiliensis) in the PBPH-HT area of PT. Sylvaduta Corporation in Kutai Kartanegara District, East Kalimantan Province

The development of industrial plantation forests or timber estates was one way to overcome the imbalance between supply and demand for wood raw materials for the forestry wood industry, namely by developing industrial plantation forests with rubber stands. The research aims to determine the stem diameter and analyze the development of diameter increments (MAI and CAI) in rubber stands in the PT Sylvaduta Corporation area. The research was carried out from March to May 2024 on rubber stands at PT. Sylvaduta Corporation is located in Kembang Janggut District, Kutai Kartanegara Regency, East Kalimantan Province, Indonesia. The research activities carried out include preparation, observation, determining sampling locations, sampling, data collection, data analysis, and reporting. The research results show that (1) the average stem diameter of rubber stands in 2022 will range from 19.37 – 21.14 cm, in 2023 it will range between 21.56 – 23.50 cm, and in 2024 it will range between 23, 83 – 25.95; (2) the average annual diameter increase (MAI) in 2022 ranges from 1.94 – 2.11 cm/year with an average of 2.02 cm/year; MAI in 2023 will range from 1.96 – 2.14 cm/year with an average of 2.05 cm/year; and MAI in 2024 ranges from 1.99 – 2.16 cm/year with an average of 2.07 cm/year; and (3) the average increase in walking diameter (CAI) in 2022 ranges from 1.72 – 1.93 cm/year with an average of 1.81 cm/year; CAI in 2023 ranges from 2.19 – 2.35 cm/year with an average of 2.29 cm/year; and CAI in 2024 will range from 2.27 – 2.46 cm/year with an average of 2.38 cm/year.