Jurnal Lahan Suboptimal : Journal of Suboptimal Lands

Evaluation of the in vitro efficacy of selected plant extracts against strawberry anthracnose disease in highlands of Sri Lanka

2025-12-19T14:04:34+07:00

Anthracnose was one of the major diseases of strawberry cultivation in Sri Lanka, caused by a fungal pathogen Colletotrichum acutatum Simmonds, and the application of synthetic fungicides was the well-known method used in disease management. Since there was a requirement to find alternative methods to control the disease, six plant extracts were tested as an organic management approach. The study aimed to evaluate the in vitro efficacy of selected plant extracts against Colletotrichum acutatum isolated from strawberry and to identify promising botanical alternatives to synthetic fungicides for sustainable strawberry cultivation in the highlands of Sri Lanka. In well diffusion test, sterilized distilled water, garlic (0.25 g/mL), Mint (0.25 g/mL), rosemary (0.25 g/mL), turmeric (0.25 g/mL), ginger (0.25 g/mL), cinnamon oil (0.25 mL/mL), Fungicide (Chlorothalonil 500 g/L SC (0.003 mL/mL) were the tested treatments. Cinnamon oil suspension (0.25 g/mL) and garlic bulb extract (0.25 g/mL) were able to control C. acutatum under in vitro conditions. However, according to the sensory evaluation test of plant extracts treated fruits, the most preferable plant extract application was garlic bulb extract, which is having significantly similar “overall acceptance” with untreated fresh strawberry fruits. Based on the results, garlic bulb extract is suggested as an organic disease management method which can be used in an anthracnose management method in organic strawberry production.

GIS–MCDA–based land suitability analysis for agrivoltaic development on degraded peatlands in South Sumatra

2025-10-22T13:15:19+07:00

Degraded peatlands in South Sumatra experience drainage driven subsidence, recurrent fires, and seasonal flooding, yet they also have reliable long term solar resources, making them strong candidates for agrivoltaics that avoids conversion of intact peat. This study aimed to map and quantify agrivoltaic land suitability on degraded peatlands using an integrated GIS and multi-criteria decision analysis workflow. Eight criteria were prepared on a 30 m UTM Zone 48S grid and normalized to a 0 to 1 benefit scale: FRP weighted fire kernel density, peat depth class as a geotechnical proxy, flood hazard index, slope, distance to roads, aspect, topographic position index, and long term global horizontal irradiance. Weights were derived with the Analytic Hierarchy Process (CR= 0.00244) and combined using Weighted Linear Combination with protected areas applied as hard constraints. Across the eligible degraded peat domain (124,007.76 ha), 53.76% (66,665.25 ha) was very suitable and 24.89% (30,867.84 ha) was moderately suitable, while 19.68% (24,408.99 ha) and 1.67% (2,065.68 ha) were unsuitable and very unsuitable. Overall, 78.65% (97,533.09 ha) of eligible land was suitable or very suitable, indicating a substantial opportunity for policy-focused agrivoltaic screening on degraded peatlands while maintaining environmental safeguards.

Efficacy test of biological agent Trichoderma spp. against white root fungus disease (Rigidoporus microporus) in rubber tree (Hevea brasiliensis)

2025-11-19T12:46:33+07:00

White root rot disease caused by Rigidoporus microporus is one of the most destructive root diseases in rubber plantations, leading to significant yield losses each year. The study aimed to evaluate the efficacy of the biological control agent Trichoderma spp. in suppressing the development of white root fungus on rubber seedlings. Laboratory assays using the dual culture method and greenhouse trials with preventive and curative applications were conducted, involving treatments with Trichoderma-based biofungicide, chemical fungicide, and control. Laboratory results showed that Trichoderma spp. inhibited the growth of R. microporus by more than 44% on the fifth day after inoculation. In greenhouse experiments, preventive application of Trichoderma spp. was more effective than curative application, as indicated by improvements in stem diameter, plant height, and the number of leaves. Besides antagonistic activity, Trichoderma spp. contributed to improved soil fertility and plant growth. The lowest disease intensity (25.2%) was observed in the preventive treatment with Trichoderma, while in curative treatments, its effectiveness was comparable to that of chemical fungicides. The findings confirm that Trichoderma-based biofungicides are effective in controlling white root rot disease while simultaneously enhancing plant growth, making them a sustainable alternative to chemical fungicides.

Ethnobotanical study of medicinal flora in the Lembak Delapan Tribe Community of Jum'at Village, Talang Empat District, Central Bengkulu Regency

2025-12-02T09:54:46+07:00

The potential for medicinal plants in Jum'at village is significant, despite the fact that many people today do not use traditional medicine due to the convenience of purchasing pharmaceuticals at stores, accessing remedies at home, or seeking treatment at health facilities or hospitals. The study aimed to identify and assess medical plant species and the socio-cultural conditions of the Lembak Delapan tribe's flora consumption in Jum'at village, Talang Empat District, Central Bengkulu Regency. This study used snowball sampling, interviews, and village tours to collect data and identify plants by comparing their characteristics to photos in plant identification literature. The findings revealed that 53 plant species used as traditional medicine were divided into 33 groups, with 10 species being the most commonly used by the community. These were the most often planted plants, others grew naturally near the hamlet. Plant medicinal components include the entire plant or specific portions (roots, stems, leaves, and fruit) and were viewed by the community as treatments for both internal and external ailments. They were processed by boiling, pounding, direct ingestion, brewing, squeezing, and incineration. We suggest that future studies collect the most recent data on the medicinal plant kinds found in Bengkulu Province and to carry out research on the chemical composition of the discovered medicinal plants.

Distribution of physicochemical in the coastal waters of Sembilang National Park, Banyuasin Regency, South Sumatra, Indonesia

2025-11-19T13:13:00+07:00

Sembilang National Park (SNP) is a large mangrove area and plays an important role in Indonesia, where it has important economic value, especially fisheries resources, a route for protected types of marine biota, and a potential fishing area. Good water quality conditions can optimize the function of the SNP area as an ecosystem for various existing biological resources. The aimed of study was to analyze the relationship between physical and chemical parameters in the inner and outer zones of the mangrove ecosystem. Data was collected directly in situ such as DO, pH, salinity, nitrate, and phosphate. Analysis of the distribution of physical and chemical water data was using Surfer 9 software. Analysis of the relationship between physical and chemical parameters using Principal Component Analysis (PCA). The results showed that the water quality in SNP was still in good condition for biota growth, however, nitrate and phosphate showed high values at 4.32-6.52 mg/land 0.12-0.19 mg/L. Principal Component Analysis (PCA) showed that the estuary zone was characterized by nitrate and phosphate parameters, while the outer estuary zone was characterized by DO, pH, and salinity parameters. The dynamics of the physicochemical parameters of the waters in the SNP area are generally in good condition, except for nitrate and phosphate, which are indicated to cause eutrophication.

River segmentation based on water quality index for management policy formulation: an analysis of the Enim River in South Sumatra

2025-09-16T09:37:37+07:00

This study aimed to delineate segments of the Enim River based on the Water Quality Index (WQI), using the Pollution Index (PI) as the primary method. Water quality data were collected from 14 monitoring stations between 2022 and 2024, covering several physicochemical and biological parameters. Hierarchical Cluster Analysis (HCA) was applied to classify stations based on similarities in pollution patterns. The results identified three main segments: stations with relatively good water quality, stations with fluctuating pollution levels, and stations with high pollution requiring priority attention. This approach provides a comprehensive spatial and temporal overview, supporting the development of more targeted and evidence-based river management policies. The study points to the WQI as an effective and accessible tool for assessing water quality, enhancing stakeholder understanding, and serving as a foundation for river conservation and restoration planning.

Leaf blight and stem rot disease infection on eucalyptus (Eucalyptus pellita)

2025-11-13T11:16:40+07:00

Eucalyptus pellita is an important plant for the pulp and paper industry. During its growth and development process, there are factors that inhibit Eucalyptus, namely stem rot and leaf blight caused by Ceratocystis and Cylindrocladium. The purpose of this study was to determine the incidence and intensity of leaf blight and stem rot diseases caused by Ceratocystis and Cylindrocladium, as well as to identify the ecological conditions and disease distribution in the Baung Central Nursery and Sungai Beyuku Nursery areas. The observation method used was direct field observation with purposive sampling and interviews with representatives from the nursery division. Symptoms of stem rot caused by Ceratocystis are indicated by streaks or lines that appear as pale brown to blackish patches on the sapwood, which result in weakened and broken stems. Symptoms of leaf blight caused Cylindrocladium include round or oval dark brown to blackish leaf spots, which in advanced stages spread to the underside of the leaf and turn black. This study concludes that disease incidence in Baung Central Nursery is dominated by leaf blight caused Ceratocystis, while in Sungai Beyuku Nursery it is dominated by leaf blight caused by Cylindrocladium.

The potential of Pterocarpus indicus as a revegetation plant for coal mine Reclamation Land

2025-09-19T06:29:08+07:00

Coal mining exploitation generally uses open-pit mining techniques that have implications for environmental degradation, particularly changes in the physical, chemical, and biological properties of the soil. Revegetation of reclaimed land is a strategy for restoring ecosystem functions that have been disrupted by mining activities. This study aimed to evaluate the growth potential of Pterocarpus indicus through direct planting methods and to assess the effect of fertiliser type on plant growth acceleration on post-coal mining land. Field observations were used to measure plant growth parameters, including height, stem diameter, and number of leaves. The planting material used was stem cuttings, with variations in fertiliser treatment. Plant material type, fertiliser type, and application dose had a significant effect on plant growth variables (P<0.05). Duncan’s multiple range test indicated that the use of bokashi fertiliser at a dose of 3 kg per planting hole gave the best results, as evidenced by an average plant height of 104.38 cm, an average stem diameter of 37.692 cm, and a total of 21.99 leaves. Therefore, the direct planting method using stem cuttings as planting material with the application of bokashi fertiliser at a dose of 3 kg plays an important role in accelerating vegetation recovery in coal mine reclamation.

Farming patterns and factors affecting rice farming income on various types of lebak swamp land in Kalidoni Sub-District, Palembang City

2026-02-20T10:59:25+07:00

Rice farming in Indonesia plays a strategic role in ensuring national food security and is a key sector for improving farmers’ welfare, especially in rural areas. The study aimed to analyze the factors influencing rice farmers’ income based on the typology of lebak swamp land, with a focus on Sungai Selincah Urban Village, Kalidoni Sub-District. The objectives were to describe rice farming patterns based on lebak swamp land typology, to analyze total farming income by land type, and to identify key determinants of income across different land typologies. The research location was selected purposively, and data were collected through a survey of 60 respondents. Data were analyzed using descriptive statistics and multiple linear regression. The results show that rice farming practices vary according to land typology, significantly affecting income levels. Among the three land types, farmers on middle lebak swamp land earned the highest income at 45,627,037 IDR/year (3,802,253 IDR/month), categorized as 'very high'. Farmers on shallow lebak swamp land earned 33,306,153 IDR/year (2,775,512 IDR/month), categorized as 'high'. Meanwhile, those on deep lebak swamp land earned 20,651,753 IDR/year (1,720,979 IDR/month), categorized as 'moderate'. The regression results indicate that land area, production volume, and farming experience positively and significantly affect income (p<0.05). Furthermore, compared to deep lebak swamp land (as the reference category), farmers cultivating shallow lebak swamp land and middle lebak swamp land types earned significantly higher income, indicating a substantial income differential across land typologies.

Agronomic evaluation of sub1-introgressed black rice lines under rainfed lowland conditions in South Sumatra

2025-10-30T21:01:22+07:00

Rice (Oryza sativa L.) is a major staple crop, and black rice is increasingly valued for its nutritional and economic importance. In South Sumatra, Indonesia, rainfed lowland swamp ecosystems offer substantial potential for rice cultivation, but productivity is constrained by alternating flooding and drought stress. The introgression of the Sub1 gene provides tolerance to submergence and supports the development of adaptive black rice cultivars. This study aimed to evaluate the agronomic performance of six black rice lines carrying the Sub1 gene under rainfed lowland conditions. The experiment was conducted using a randomized complete block design with three replications. Agronomic traits, including phenology, tillering, yield components, and grain yield, were recorded and analyzed using analysis of variance, correlation, and principal component analysis (PCA). Significant differences among genotypes were observed for most agronomic traits, indicating substantial genetic variability. Regita5 and Febry1 showed superior performance, producing the highest grain yields of 3.53 and 3.37 t/ha, respectively, supported by higher numbers of productive tillers and filled grains per panicle. Correlation and PCA results revealed that grain yield was primarily influenced by tillering capacity and grain production traits, whereas 100-grain weight and phenological traits contributed weakly or negatively. These findings demonstrate that black rice lines carrying the Sub1 gene, particularly Regita5 and Febry1, possess strong agronomic potential for cultivation and as breeding materials in stress-prone swamp ecosystems, contributing to sustainable rice production under climate variability.

Acidic soil amelioration strategies for improving soil fertility: a systematic literature review of techniques, materials, and mechanisms

2026-02-12T11:26:26+07:00

Declining agricultural productivity in tropical and subtropical regions is largely due to high soil acidity, which inhibits nutrient availability and increases the solubility of toxic elements such as aluminum and iron. Acidic soil is one of the main constraints in agricultural systems, characterized by low soil pH and an imbalance of essential nutrients for plants. This study aimed to systematically review various approaches to acid soil amelioration, focusing on the mechanisms and materials used. The method used in this study was a Systematic Literature Review (SLR), through an analysis of 38 reputable scientific articles published between 2021 until 2025 and indexed in the Scopus database. The article selection process was based on inclusion criteria specifically related to the results of acidic soil amelioration research. The synthesis results show that acidic soil amelioration approaches could be grouped into several main categories, namely liming-based, biochar-based, biochar and organic-based, organic (non-biochar)-based, organomineral-based, and industrial waste-based. Although research on acid soil amelioration has developed rapidly, there was still considerable variation in the selection of materials, composition, and application methods used. Overall, this systematic literature review provides a structured overview of the mechanisms and materials used in acid soil amelioration.

Knowledge and adaptation strategies of coffee smallholders toward climate change: evidence from Tanjung Agung, Semende Darat Ulu

2025-09-16T10:33:27+07:00

Coffee farming was highly vulnerable to the impacts of climate change. Exploring the strategies used by small farmers in Tanjung Agung Village has had a big impact on climate change. This study aimed to identify the level of knowledge, adaptation practices, and polyculture practices and types of shade trees used by coffee smallholders in facing climate change in Tanjung Agung Village, Semende Darat Ulu Regency. These strategies have made a significant difference. This study used a qualitative, survey-based approach. It also conducted data collection and analysis. This process was both simultaneous and cyclical coffee smallholders have noticed the effects of climate change in the last 1-2 years. Also, 35% of smallholders have known about climate change for the last 3-5 years. Coffee smallholders use indicators to predict climate change. These indicators include increased temperatures and shifts in the rainy and dry seasons. Water availability was also an indicator. Up to 90% of small farmers take steps to reduce climate change. These steps include using better types of coffee, planting trees for shade, and controlling how far apart the coffee plants were. Farmers also make air holes and use coffee bean skins to improve the soil. Our findings show that coffee smallholders understand climate change impacts well. They also quickly use strategies to adapt their crops to the changing climate. Smallholders use 16 types of shade crops as a strategy. The most widely used shade crops were petai, mango, avocado and durian.