Journal of Tropical Crop Science
Not a member yet
315 research outputs found
Sort by
Cryopreservation of Terap (Artocarpus elasticus Reinw. ex. Blume) Seeds: Viability and Structural Characterization
No full textTerap (Artocarpus elasticus Reinw. ex Blume) is an underutilized fruit tree native to Indonesia, valued both for its edible fruit and its diverse applications in traditional medicine. Terap seeds are recalcitrant, so cryopreservation is the most effective method for their long-term preservation. This study aimed to determine the optimal loading and vitrification times for cryopreservation to maintain seed viability. A factorial, completely randomized design was employed with two factors: loading time (0 and 20 min) and vitrification time (0, 30, and 60 min). Seed viability after loading and vitrification treatment with or without freezing in liquid nitrogen was evaluated using tetrazolium chloride (TTZ) and germination tests. Results indicated that the loading and vitrification treatments did not yet improve the viability of terap seeds after cryopreservation, as determined by the TTZ and germination tests. The TTZ test showed that the viability of all treated seeds decreased, regardless of whether they were frozen in liquid nitrogen. Germination tests revealed that all treated seeds without freezing had reduced germination, while none of the seeds treated with freezing germinated. Structural analysis indicated that freezing alters cell degradation, likely due to the formation of ice crystals and mechanical stress. To improve the success of terap seed cryopreservation, future efforts should focus on optimizing exposure times, reducing PVS2 toxicity, and enhancing cryoprotectant penetration by removing the seed coat or using the embryo axis as an explant
Assessment of Major Diseases and Insect Pests of Horticultural Crops in Eastern Amhara, Ethiopia
Full text linkDiseases and insect pests are serious problems affecting horticultural crops grown in mid and lowland areas. A systematic survey was conducted to assess the distribution, incidence, and severity/damage levels of diseases and insect pests of horticultural crops in the mid- and lowland areas of the North and South Wollo zones (Kalu, Tehuledere, Habru, and Kobo districts) during the 2017/2018 main and irrigation seasons. During the survey, a total of 279 fields on 14 different horticultural crop types were addressed. As revealed by the assessment, horticultural crops are subjected to numerous pests. Citrus woolly whitefly (Aleurothrixus floccosus) and leaf miner (Phyllocnistis citrella) on citrus; fruit flies (Thepritidea species) on coffee; diamondback moth (Plutella xylostella) on cabbage; and thrips on onion were the most destructive insect pests in the area. Especially, woolly whitefly in Kobo and leaf miner in Kalu districts were the major pests of citrus, with severities of 38.97% and 31.84%, respectively. Regardless of location, leaf miner was the most severe pest (42.31%) at the seedling stage of citrus. whereas, anthracnose (Colletotrichum species) and powdery mildew (Oidium caricae) on mango, anthracnose on avocado, purple blotch (Alternaria porri) on onion, and black sigatoka (Pseudocercospora fijiensis) on banana were found to be the major diseases in their order of damage level and occurrence. This clearly indicates the need for regular and targeted pest monitoring on the one hand and the development of management options for the most important horticultural crop pests of the area on the other
Improved Performance of SiDREB2-SNAP Marker in Foxtail Millet by Optimum Primer Concentration, PCR Cycle, and DNA Polymerase Specificity
Full text linkFoxtail millet (Setaria italica L. Beauv.) is an emerging carbohydrate-producing crop. It is considered a climate-resilient crop due to its tolerance to abiotic stresses. Breeding for abiotic-tolerant crops requires powerful tools such as molecular markers. The single-nucleotide amplified polymorphism (SNAP) marker, developed from a single-nucleotide DNA variation at a specific location in the plant genome, is a simple yet powerful PCR-based marker widely used in phenotype-related selection. A SiDREB2-based SNAP marker was previously developed based on a base variation at the 558th base pair (an A/G transition) in the SiDREB2 gene and used to estimate the drought tolerance in foxtail millet. However, the specificity of the marker depends on technical aspects, including the type of DNA polymerase used, primer concentration, and the number of PCR cycles. Here, we reported that non-specific and false positive amplicons can be eliminated by utilizing DNA polymerase with no 3’ to 5’ proofreading activity and reducing the final primer concentration to 1.25 μM. PCR cycle number 25 yielded the optimum specificity, while increasing the cycle to 30 resulted in false positive results. Altogether, our results showed that technical optimization is necessary for improving the specificity of the SNAP marker
Effects of Chicken Manure Dose and Application Timing on the Productivity and Microbiological Safety of Lettuce (Lactuca sativa L.)
No full textOrganic lettuce is widely regarded as a healthier alternative because it is free of chemical contaminants. Chicken manure is commonly used as an organic fertilizer because of its high nutrient content, which is readily available to plants. However, applying manure poses a risk of pathogenic bacterial contamination. This study aimed to evaluate the effects of different chicken manure doses and application times, as well as their interactions, on lettuce (Lactuca sativa L.) productivity and microbiological safety. The experiment was conducted from March to May 2023 in Cianjur, West Java, using a factorial randomized block design (RBD) with three replications. Treatments included a control and two factors: (1) manure dose (10, 20, and 30 t/ha), and (2) application times (1, 2, and 3 weeks before transplanting). Microbiological analysis of harvested lettuce leaves was performed in the laboratory to assess contamination levels of Escherichia coli, Salmonella spp., and Shigella spp. Manure doses significantly influenced all growth and yield parameters but had no significant effect on quality variables, including flavonoid, nitrate, and total chlorophyll content. Application times showed no significant effect on any measured parameter. The interaction between dose and time was also not statistically significant for most variables. The highest productivity and marketable yield were observed at the 30 t/ha dose. Salmonella spp. was not detected in any samples; however, E. coli and Shigella spp. were present in all samples at levels exceeding the Indonesian National Standard (SNI) for food safety. In addition to the required dose of chicken manure, to minimize microbial contamination, fully decomposed manure is recommended for application, as it can be applied to land shortly before planting. The use of microbial-free water for washing vegetables is recommended, including in further research
Coffee (Coffea spp.) Production Systems, Postharvest Innovations, and Quantitative and Agroecological Dynamics in the Davao Region, Philippines
No full textCoffee (Coffea spp.) is a globally significant tropical plantation crop, and the Davao Region in the Philippines is one of the country’s most dynamic production zones, thanks to its favorable volcanic soils, diverse microclimates, and evolving value chain ecosystems. With an estimated 15,821.68 ha under cultivation, the region supports all major Coffea species. Coffea arabica thrives above 1,000 m asl in highland zones such as Balutakay, Maragusan, and upland Davao City; Robusta dominates lower elevations, while Liberica and Excelsa occupy smaller areas as complementary tropical crop components. Agroecological sustainability is promoted through shade-based agroforestry systems that enhance biodiversity, soil fertility, and climate resilience. Postharvest innovations such as natural, honey, and micro-lot fermentation, alongside the expansion of community-based roasting facilities, have enabled specialty-grade production and improved access to premium domestic and international markets. Emerging trends presented at the Davao Regional Coffee Expo (DRCE) 2025 include the increased adoption of climate-resilient genetic varieties artificial intelligence-based plantation monitoring, gender-inclusive entrepreneurship, and youth participation in value-added roles such as roasting, cupping, and barista craftsmanship. However, persistent constraints, including aging plantations, low productivity, limited seedling supply, postharvest infrastructure gaps, market dependency on intermediaries, and inconsistent institutional support, continue to limit the sector’s tropical crop competitiveness. This status report consolidates insights on production systems, agroecological management, postharvest innovations, and socio-economic challenges to provide a strategic outlook for strengthening coffee as a sustainable tropical plantation crop within the Davao Region and similar highland environments in Southeast Asia
Genetic Variability, Correlation, and Path Analysis in F2 Population of Sorghum
Full text linkIndonesian sorghum (Sorghum bicolor L.) germplasm with the highest genetic diversity can serve as a valuable resource for developing high-yielding cultivars. Therefore, the present research aimed to obtain information on genetic variability in the population and also determine the key traits associated with grain yield using correlation and path analysis in sorghum F2 population. The sorghum parental genotypes 'Demak 4' and 'Soraya 3', and a local high yielding IPB line, NS 19, NS 109, and NS 111, were used in the crosses. The F2 population was evaluated against parental cultivars and four check genotypes. The results showed that 64 individual plants were observed as transgressive segregants. Meanwhile, the number of leaves and plant height were controlled polygenically through additive genes. The traits of panicle diameter, dry panicle weight, and grain weight per panicle possessed the highest genotypic coefficient of variance. The traits dry panicle weight and diameter were significantly positively correlated with grain yield. The considerable positive correlation with dried panicle weight, panicle length, and diameter could be used as selection criteria. The path analysis reported that the observed agronomic traits explained 97.07% of the total variation in grain weight per panicle
Optimizing the Application of Complete Microfertilizer in Fertigation for Cayenne Pepper (Capsicum frutescens L.)
Full text linkCayenne pepper (Capsicum frutescens) is one of the important horticultural commodities in Indonesia. According to Central Statistics Agency data, annual consumption has been rising amid fluctuating production, including a 37.68-thousand-ton decline in 2023 compared with 2022. Cayenne pepper requires a specific nutrient profile to achieve optimal yields. Micronutrients, including boron, copper, iron, manganese, molybdenum, and zinc, are vital for photosynthesis, flower development, and nutrient uptake; deficiencies impair growth, fruit quality, and disease resistance, underscoring the need for balanced fertilization. Micronutrient deficiencies can reduce plant growth, fruit quality, and disease susceptibility. Research on micronutrient provision in cayenne pepper plants remains limited. This research aims to determine the most effective method of nutrient application for cayenne pepper plants. The design used was a single-factor randomized group design. The results of the study demonstrate that micronutrient applications can increase the height and diameter of cayenne pepper stems, with foliar spray applications yielding the best response in terms of vegetative parameters. However, micro-nutrient application has not significantly affected the yield and yield components of cayenne pepper
The Potential of Metarhizium anisopliae (Metsch.) Sorokīn as the Biocontrol Agent Against Cacao Pod Borer (Conopomorpha cramerella Snellen)
Full text linkMetarhizium anisopliae (Metsch.) Sorokīn is an entomopathogenic fungus with broad bio insecticidal potential, widely recognized for its role in sustainable pest management. This review examines the taxonomy, pathogenesis, infection symptoms, environmental requirements, host specificity, and dual role as both a biocontrol agent and an endophyte. Special emphasis is placed on its efficacy against the cacao pod borer (Conopomorpha cramerella Snellen), a significant pest in Southeast Asia that causes yield losses exceeding 50% in cacao plantations. Laboratory and semi-field studies report larval mortality rates of up to 80%–90% under controlled conditions. However, field-level efficacy varies due to environmental factors such as temperature, relative humidity, UV exposure, and soil characteristics. The review also discusses formulation strategies, including conidial suspensions and granular formulations, that improve fungal persistence and infection success. Despite promising outcomes, the effectiveness of M. anisopliae is influenced by strain variability, local adaptation, and integration with cultural practices. Understanding these dynamics is crucial for optimizing the application of this approach in integrated pest management (IPM) systems and advancing sustainable cacao production
Effect of GA3 Application on the Germination of 5-Year Stored Bambara Groundnut (Vigna subterranea (L.) Verdc.)
No full textBambara groundnut (Vigna subterranea (L.) Verdc.) is a leguminous crop originating from North Africa, valued for its high protein and carbohydrate content, as well as its ability to adapt to marginal environments. These characteristics make it a promising candidate to support food and nutritional security, particularly in tropical regions. However, its cultivation and seed quality management remain limited, requiring strategies to improve germination and seedling establishment. Gibberellic acid (GA3) is a plant growth regulator widely known to stimulate seed germination and enhance vigor. This study aimed to assess the effect of GA3 on the germination performance of Bambara groundnut seeds stored for five years. Three genotypes (SS 3.4.2, BBL 1.1, and TVSU 8.6) were treated with GA3 at concentrations of 0, 75, 150, and 225 ppm, and germination and vigor parameters were evaluated. The results showed that GA3 application improved the performance of aged seeds, with 225 ppm identified as the most effective dose. Genotype SS 3.4.2 responded particularly well at this concentration, while BBL 1.1 consistently exhibited superior overall performance across treatments. These findings highlight the potential of GA3 to mitigate the adverse effects of seed aging and enhance seedling establishment. The application of GA3 represents a practical approach for improving the viability of stored seeds
Effect of Shape and Size of Purple Nutsedge (Cyperus rotundus L.) Tuber Bioherbicide Granules on the Germination of Weed and Crop Seeds
No full textThe use of synthetic herbicides is an effective way to control weeds, but their widespread use has negative environmental impacts. A bioherbicide made from purple nutsedge tubers can be an alternative for weed control. Purple nutsedge’s tuber contain allelopathy compounds that can inhibit the growth of other plants (weeds). This study aims to evaluate the response of various shapes and sizes of bioherbicide granules made from purple nutsedge’s tuber in suppressing the germination of weed seeds and crop seeds. The experiment used a completely randomized design one factor and eleven treatments: control without herbicide treatment, synthetic herbicide active ingredient oxyfluorfen 240 g/L, purple nutsedge’s tuber powder bioherbicide without carrier, very small round granule bioherbicide, small round granule, medium round granule, large round granule, very small cylindrical granule, small cylindrical granule, medium cylindrical granule, and large cylindrical granule. Each treatment was tested on four species: Bidens pilosa and Cynodon dactylon (weeds), cucumber, and rice (crops). The experimental results showed that the application of purple nutsedge’s tuber-based bioherbicides exerts a noticeable influence on several germination parameters. The smaller the bioherbicide granule, the higher the germination inhibition rate. Very small, round-shaped granule bioherbicides showed greater effectiveness in suppressing seed sprout percentage, reducing growth rate, increasing the percentage of abnormal sprouts, and inhibiting plumula and radicle growth