Contributions of Central Research Institute for Agriculture

Analysis of biotic disease incidence and abiotic disorders in oil palm (Elaeis guineensis Jacq.) main nursery at Adolina Estate

Andri Wijaya Panjaitan — 2026-07-01

This study aimed to identify biotic diseases and abiotic disorders and determine their percentage and intensity in oil palm main nursery seedlings. The research was conducted at the Adolina Oil Palm Seed Center, PT Perkebunan Nusantara IV Regional II, using a quantitative descriptive method through direct observation of 400 oil palm seedlings. Data were collected through visual assessment and analyzed using disease incidence and severity formulas. The results showed that leaf spot disease was the most prevalent biotic disease, affecting 91 seedlings (22.75%) with a disease intensity of 7.88%, followed by anthracnose affecting 81 seedlings (20.25%) with an intensity of 6.50%. Several abiotic disorders and genetic abnormalities, including chimera, dwarfism, rolled leaves, crinkled leaves, grass leaf, juvenile characteristics, and short internodes, were also identified at relatively low and stable frequencies. Overall, disease severity levels were classified as mild (1.1–25.0%). Environmental conditions, particularly high humidity and nursery sanitation practices, were found to significantly influence disease development. These findings highlight the importance of proper sanitation, environmental management, and the use of healthy seedlings to minimize disease incidence and improve nursery quality.

Effects of manure and liquid organic fertilizer from onion peel waste on the growth and yield of sweet corn (Zea mays L. var. saccharata)

Erlita Erlita — 2026-07-01

Sweet corn is a high-value horticultural crop that responds strongly to organic nutrient management. This study evaluated the effects of manure type, the concentration of liquid organic fertilizer from onion peel waste (POC), and their interaction on sweet corn grown in Inceptisol field soil at Kwala Bekala, Medan Johor, North Sumatra. The experiment was conducted from March to June 2026 using a factorial randomized block design with three replications. The first factor was manure type: no manure (K0), chicken manure 2 kg/plot (K1), cattle manure 2 kg/plot (K2), and goat manure 2 kg/plot (K3). The second factor was onion peel POC concentration: no POC (P0), 250 ml/L (P1), and 500 ml/L (P2). The observed variables were plant height, stem diameter, cob length, cob diameter, and yield weight per plant. Manure significantly affected plant height and had a highly significant effect on stem diameter, cob diameter, and yield weight. Onion peel POC had a highly significant effect on stem diameter, cob diameter, and yield weight. The interaction significantly affected plant height, stem diameter, and cob diameter and had a highly significant effect on yield weight. K2P2 produced the tallest plants, largest stem diameter, and largest cob diameter, whereas K3P1 produced the highest yield weight (261.00 g/plant), a 72.85% increase over the untreated control (K0P0, 151.00 g/plant). Thus, 2 kg/plot of goat manure combined with 250 ml/L of onion peel POC is recommended to improve sweet corn yield.

"Struktur Komunitas Makroinvertebrata Tanah pada Berbagai Tingkat Paparan Pestisida di Perkebunan Kelapa Sawit Desa Mega Timur"

Erwan Erwan — 2026-07-01

Penelitian ini bertujuan untuk menganalisis dampak aplikasi berbagai konsentrasi pestisida sintetis terhadap keanekaragaman dan keberadaan makroinvertebrata tanah pada perkebunan kelapa sawit di Desa Mega Timur, Kabupaten Kubu Raya. Penggunaan pestisida yang intensif untuk mengendalikan hama berisiko merusak biota tanah non-target yang berperan krusial dalam proses dekomposisi dan pemeliharaan struktur fisik tanah. Penelitian dilakukan melalui metode survei dengan Rancangan Acak Kelompok pada 60 unit contoh tanah yang mencakup variasi konsentrasi pestisida (2, 4, 6, 8, dan 10 ml/L) serta variasi kedalaman tanah (10, 20, dan 30 cm). Parameter yang diukur meliputi kepadatan, kepadatan relatif, dan frekuensi kehadiran. Hasil pengamatan sebelum perlakuan menunjukkan adanya makrofauna seperti cacing tanah, semut, laba-laba, dan kelabang (Chilopoda) dalam kategori frekuensi kehadiran "Aksidental" (0-25%). Namun, satu bulan setelah aplikasi pestisida, ditemukan hilangnya seluruh individu makroinvertebrata (nihil) di semua plot pengamatan dan seluruh kedalaman tanah. Kondisi ini mengindikasikan adanya dampak letal menyeluruh dan persistensi residu kimia (sekitar 80% mengendap di tanah) yang merusak habitat bioindikator hingga kedalaman 30 cm. Kesimpulannya, penggunaan pestisida sintetis pada rentang konsentrasi tersebut menyebabkan kerusakan habitat makroinvertebrata secara total, yang dalam jangka panjang dapat mengancam fungsi biologis, kesuburan alami, serta produktivitas ekosistem lahan sawit.

Identification dominance and impact of Imperata cylindrica in oil palm plantations: a literature review

Farhan Zaky — 2026-07-01

Weeds are a major obstacle in oil palm cultivation, as their presence can disrupt plant growth through competition for nutrients, water, sunlight, and growing space. One of the most dominant weeds found in oil palm plantations is Imperata cylindrica. This study aims to identify the characteristics, level of dominance, and effects of Imperata cylindrica on oil palm plants. The method used in this study is a literature review, based on various national and international scientific journals related to Imperata cylindrica and oil palm plantations. The results show that Imperata cylindrica is an invasive weed from the Poaceae family with high adaptability, an extensive rhizome system, and rapid reproduction through seeds and rhizomes. Its presence causes intense competition for nutrients, water, and light, and it also produces allelopathic compounds that inhibit plant growth. The dominance of this weed is strongly influenced by open land conditions with high light intensity. In conclusion, Imperata cylindrica has a significant negative impact on the growth and productivity of oil palm plants. Therefore, integrated weed control methods, including mechanical, chemical, and cultural approaches, are necessary to maintain optimal plantation productivity.

Morpho-agronomic description of local red chili ‘Justiber’ based on limited field observations in North Sumatra

Gali Rakasiwi — 2026-07-01

Local chili pepper germplasm is an important genetic resource for crop improvement because it may harbor useful phenotypic variation in vegetative vigor, plant architecture, reproductive timing, and productivity. This study examined the morpho-agronomic traits of the local red chili ‘Justiber’ as preliminary baseline information for future descriptor-based evaluation and population expansion. The study was conducted in Simpang Selayang Village, Medan Tuntungan District, North Sumatra, Indonesia, from January to March 2026. The observed parameters included dichotomous height, plant height, stem diameter, days to flowering, number of branches, leaf length, and days to first harvest. From an initial field planting of 30 plants, only 10 normally growing plants that could be monitored consistently until first harvest were used as observation units; stunted or abnormal plants were excluded and are acknowledged as a limitation. This exploratory study did not compare treatments or genotypes; therefore, the data were analyzed descriptively using the mean, standard deviation, range, coefficient of variation, and 95% confidence interval. The results showed mean values of 77.40 ± 9.70 cm for plant height, 9.40 ± 0.97 mm for stem diameter, 57.00 ± 1.49 days after planting for flowering, 4.70 ± 1.25 branches, 8.10 ± 0.76 cm for leaf length, and 89.70 ± 1.64 days after planting for first harvest. The highest coefficient of variation was observed for number of branches (26.63%), whereas days to first harvest showed the lowest variation (1.82%). These findings indicate that the observable variation of ‘Justiber’ was concentrated mainly in vegetative architecture, while reproductive timing was relatively synchronized.

Harvesting standard operating procedures and fresh fruit bunch quality in oil palm: literature review

Immanuel Simangunsong — 2026-07-01

The quality of fresh fruit bunches (FFB) is one of the key factors affecting the productivity and efficiency of the palm oil industry. Improper harvesting practices may lead to increased losses, reduced oil extraction rates, and deterioration of fruit quality. Therefore, the implementation of harvesting Standard Operating Procedures (SOPs) is essential to ensure that harvesting activities are carried out effectively and consistently. This study aimed to examine the role of harvesting SOPs in maintaining the quality of oil palm fresh fruit bunches through a literature review approach. Literature data were collected from scientific publications indexed in Sinta and Scopus databases using the keywords oil palm harvesting, fresh fruit bunch quality, harvest losses, free fatty acid, harvesting SOP, and post-harvest handling. A total of 25 articles published between 2018 and 2025 were selected based on predetermined inclusion criteria. The collected literature was analyzed descriptively through comparison and synthesis of findings from previous studies. The review indicates that the implementation of harvesting SOPs is associated with improved compliance with fruit maturity standards, reduced harvest losses, lower risk of free fatty acid formation, and improved maintenance of fruit quality. The literature also highlights the importance of worker competence, supervision, transportation management, and adherence to harvesting schedules in supporting effective SOP implementation. Conversely, inadequate harvesting practices may negatively affect fruit quality and plantation performance. In conclusion, harvesting SOPs play an important role in maintaining the quality of oil palm fresh fruit bunches and supporting sustainable plantation management. Continuous training, monitoring, and evaluation are recommended to strengthen SOP implementation and improve harvesting performance.

Utilization of palm oil derivatives for eco-friendly industrial development: literature review

Lilis Pebriani Hutajulu — 2026-07-01

The increasing adoption of eco-friendly industrial practices and circular economy principles has encouraged the palm oil industry to maximize the utilization of waste and by-products as valuable resources. This study aims to examine the potential utilization of palm oil derivatives in supporting environmentally friendly industrial development through a circular economy approach. A descriptive qualitative method with a literature review approach was employed using secondary data obtained from 25 national and international journal articles, scientific papers, and conference proceedings published between 2019 and 2026. Relevant literature was collected from Scopus, ScienceDirect, Google Scholar, and MDPI databases using keywords related to palm oil waste, circular economy, biomass, bioenergy, and sustainable industry. Data were analyzed through content analysis involving identification, selection, classification, synthesis, and conclusion drawing. The results indicate that various palm oil derivatives, including Palm Oil Mill Effluent (POME), empty fruit bunches, biomass residues, boiler ash, and oleochemical by-products, can be utilized as renewable energy sources, organic fertilizers, biomaterials, bioplastics, and industrial raw materials. The implementation of circular economy principles contributes to reducing environmental pollution, improving resource efficiency, decreasing dependence on fossil fuels, and supporting sustainable industrial development. However, several challenges remain, including high investment costs, limited technological adoption, and inadequate industrial integration. Overall, palm oil derivatives should be viewed as strategic resources capable of supporting environmental sustainability, industrial competitiveness, and long-term economic development.