Journal of Tropical Crop Science
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Purple Cleome (Cleome rutidosperma) Growth, Yield, and Total Flavonoid Under Different Media Compositions and Harvesting Frequencies
No full textPurple cleome (Cleome rutidosperma) is a medicinal plant known for its flavonoid content, which confers multiple pharmacological benefits. However, cultivation methods to optimize both biomass production and bioactive compound accumulation remain underdeveloped. This study aimed to assess the influence of planting media composition and harvesting frequency on the growth, yield, and total flavonoid concentration of purple cleome. The experiment was conducted in Gunung Batu, Bogor, Indonesia, from January to April 2025, employing a two-factor randomized block design. The first factor was planting media composition, with four treatments: 100% soil (0) and soil mixed with cow manure at ratios of 1:1, 1:2, and 1:3 (v/v). The second factor was harvesting frequency, with two levels: A single harvest at 8 weeks after planting (WAP) and two harvests at 4 and 8 WAP. Results indicated that all tested media compositions supported plant growth effectively. Notably, total flavonoid concentration was significantly higher at 4 WAP compared to 8 WAP. Moreover, cumulative flavonoid yield from two harvests was significantly greater, reaching 5,639.80 mg quercetin equivalents (QUE) per plant dry weight, compared to 1,456.50 mg QUE per plant from a single harvest. These findings suggest that harvesting at multiple intervals enhances flavonoid yield in purple cleome cultivation
Optimizing Rice Seed (Oryza sativa L.) Production and Quality through Organic Fertilizer Application
Full text linkRice (Oryza sativa L.) is a vital cereal crop and primary food source for over half of the global population, especially in Asia, Africa, and Latin America. This study evaluated the effect of organic fertilizers on optimizing rice seed production and quality. Organic fertilizers improve soil physical, chemical, and biological properties, thereby enhancing nutrient availability. A study was conducted standard and premium organic fertilizers (petroganik), in a completely randomized design with six treatments: no fertilizer (control), (12.5% organic C) at 500 kg/ha, and the premium organic fertilizer (15% organic C) at 250, 500, 750, and 1000 kg/ha. With four replications, 24 experimental plots were established. Results showed that while application of premium organic fertilizer did not affect vegetative growth, it significantly increased the number of productive tillers and overall yield. Applying 500 kg/ha of premium organic fertilizer increased rice yield by up to 13% compared to the control, with a relative agronomic effectiveness of >95%. Seed quality improved, indicated by higher germination rates, vigor index, and maximum growth potential. The after-ripening period was shortened by two weeks compared to control seeds, i.e., from 5 to 3 weeks, but did not affect seed storability
Potential of Silybum marianum Aqueous Extract to Inhibit Rhizoctonia solani Growth and Pathogenesis
Full text linkThe present study evaluated the effects of a cold aqueous extract of milk thistle (Silybum marianum) on the growth of the soil-borne pathogen Rhizoctonia solani and on wheat seed germination and seedling development. In vitro assays demonstrated that the extract significantly inhibited fungal growth, with concentrations up to 7.5% completely preventing proliferation. Pot experiments further revealed that soil treated with both R. solani biomass and its culture medium, particularly in the presence of milk thistle extract, resulted in a drastic reduction in wheat seed germination to 30% and complete seedling mortality within 10 days. Notably, when fungal biomass and its medium were treated with increasing concentrations of milk thistle extract (2.5%–10%), wheat seed germination rates improved markedly, ranging from 83% to 93%. In comparison, seedling death decreased from 16% to 10%. Furthermore, seedlings grown under these conditions exhibited significant increases in shoot and root length, as well as overall biomass, compared with controls grown on potato dextrose agar (PDA) alone. These results suggest that milk thistle extract may serve as an effective pre-planting seed treatment, enhancing wheat germination and seedling vigor while reducing susceptibility to Rhizoctonia solani during early developmental stages
Economic Viability and Ecological Outcomes of Organic Horticulture: Evidence from Highland Farming Communities in Bali, Indonesia
No full textOrganic horticulture is an essential component of sustainable agriculture, offering agronomic, ecological, economic, and social benefits. This study investigates the economic viability and ecological outcomes of organic horticultural practices among highland farming communities in Bali, Indonesia. Utilizing a case study of certified organic farmer groups, data were collected via interviews, field observations, and secondary sources. Analysis included market trends, cost-benefit ratios, productivity, and environmental indicators. Findings show that organic horticulture enhances soil fertility with compost and manure, and manages pests through crop rotation, intercropping, and plant derived pesticides. Economically, organic horticulture is highly profitable, with a benefit-cost (B/C) ratio of 14.18, driven by strong consumer demand for pesticide-free produce in urban and tourist markets. Environmentally, organic farming reduces chemical contamination, boosts soil organic matter, and strengthens agroecosystem resilience. Socially, it promotes cooperative farming, knowledge sharing, and community engagement. Challenges include higher input costs, complex certification processes, and limited access to organic farming technology. This research’s novelty is its integrative assessment of agronomic productivity, environmental sustainability, and economic feasibility in a unique tropical context, offering a holistic sustainability model. Findings contribute to organic agribusiness theory, sustainable development, and resilient food system policymaking
Fruit and Seeds Development and Seed Germination of Andaliman Pepper (Zanthoxylum acanthopodium DC.)
Full text linkAndaliman is a species found in the Lake Toba region of North Sumatra, Indonesia. To determine its optimal harvest time and the length of its physiological maturity, it is necessary to observe fruit development in new locations outside its natural habitat. Andaliman seeds are known for their low germination rates and are classified as endospermic seeds. This study aims to analyze the stages of fruit and seed development, evaluate the effects of seed treatments, and identify the most effective germination test methods for andaliman seeds. Seeds were treated with a 50% H2SO4 solution for 15 min and with a 200 ppm GA3 + 100 ppm kinetin solution for 48 hr. The seeds were then tested using pleated paper and top paper media to assess germination response. Changes in fruit coloration indicated various stages of development: intense yellowish-green at 17 weeks after anthesis, deep yellowish-green at 20 weeks, deep red at 23 weeks, and dark greyish-yellowish-brown at 26 weeks. During development, some fruits experienced embryo abortion, resulting in many empty or wrinkled seeds. The seeds reached physiological maturity at 23 weeks after anthesis, as indicated by a deep red fruit color, increased seed dry weight, and enhanced germination and seed growth rates. The treatment with GA3 and kinetin yielded the highest germination rate of 20%, with the pleated paper method proving to be the most effective for germination testing
Effects of Ethephon and Fertilization on Latex Physiology and Rubber Yield in GT1, BPM 24, PB260 and IRR112 Clones
Full text linkThis study was conducted to evaluate the effects of ethephon stimulation and fertilization on latex production and physiological latex in different clones. This study was conducted in the experimental field of the Indonesian Rubber Research Institute in South Sumatra. The experiment was laid out in a randomized complete block design with three replications. The main block is the rubber clones, and the subblocks are fertilization rate and ethephon stimulation. The rubber clones for this research were GT 1, BPM 24, PB 260, and IRR 112. The different fertilization rates used in the experiment were control (no fertilizer), 50% recommended rate (50 RR), 100% recommended rate (100 RR), and 150% recommended rate (150 RR). Ethephon stimulation was applied every two months during the observation period with a rate of S/2 d3 ET2.5% 6/y. The observed parameters included: latex yield, physiological latex (sucrose, inorganic phosphorus, and thiol), and tapping panel dryness. Results showed that rubber yields, such as latex production and dry rubber content, increased by 10%–16% with fertilization and ethephon stimulation. Latex characteristics, including thiol, inorganic phosphate, and sucrose, remained within their optimal ranges, with thiol levels increasing from 0.11 to 0.29 mM, inorganic phosphate from 7.29 to 1.58 mM, and sucrose from 0.42 to 7.12 mM upon fertilization
Improvement of Chlorophyll, Antioxidant Properties, and Biomass Yield in Sweet Basil (Ocimum basilicum L.) Using Chitosan at Various Growing Stages
Full text linkSweet basil (Ocimum basilicum L.) is known for its numerous health-promising antioxidant phytochemicals and is primarily used in nutritive, medicinal, and cosmetic products. Previous attempts to increase the antioxidant content of sweet basil were associated with disadvantages, including ecological problems, reduced biomass yield, and increased cost. Alternatively, the current study aimed to improve selected antioxidants and biomass yield by using chitosan as an organic and cost-effective growth promoter. In this experiment, a total of four different concentrations of chitosan were applied ( 0%, 0.2%, 0.4%, and 0.6% v/v) at two different growing stages: early growth stage (GS1: 45-day-old plant), late growth stage (GS2: 65-day-old plant), and at both growth stages (known as GS3: 45 & 65-day-old plants). Results showed that plants treated with 0.4% chitosan at GS1 reached the highest chlorophyll a (4.33 mg/cm2), chlorophyll b (2.50 mg/cm2), total chlorophyll (6.84 mg/cm2), total leaf area (2234.31 cm2), total dry biomass (22.72 g per plant), total flavonoid content (33.23 mg QUE/g DE) and DPPH inhibition (92.34%) compared to other treatments. Based on the yield and phytochemical content, it is recommended to apply chitosan at 4% on the 45-day-old plant
Analysis of Farmers’ Indigenous Knowledge, Perceptions, and Practices Used in the Control of Parasitic Weed Striga among Maize and Sorghum Farmers in Northern Nigeria
Full text linkThis study examined the socio-economic impact of the parasitic weed Striga infestation and the effectiveness of local and conventional control measures in Nigeria’s Gombe, Kano, and Jigawa States. Cross-sectional data from 925 respondents in 2020 was analyzed using descriptive and inferential statistics. Most respondents were male (94.8%), married (85%), and engaged in crop production (64%). The average landholding per household was 2 hectares, primarily used for cereal and legume cultivation, such as maize, sorghum, cowpea, and millet. The majority practiced mixed cropping (88%). Soil texture, moisture retention, color, and grass species appearance were used to assess farmland fertility. Striga infestation’s negative effects included stunted growth (59%), yellowing of crops (57%), yield decline (51%), and soil fertility reduction (19%). Respondents considered continuous cropping (63%), low fertilization (89%), poor crop management (79%), low rainfall (45%), and high temperature (45%) as the main causes of Striga infestation. Farmers used various methods for control, including appropriate fertilizer application (75%) and weeding (68%). Indigenous methods like a mixture of salt and potash and Parkia fruit powder were also common. The effectiveness of indigenous and conventional methods showed no significant difference between Jigawa and Katsina. In conclusion, Striga infestation significantly threatens crop production, income, and food security. It can be managed through both conventional and indigenous methods. Efforts should focus on educating farmers about agronomic practices to mitigate Striga infestation and promote the adoption of Striga-resistant crop varieties, especially in Striga-prone areas
Genetic Variability of Echinochloa crus-galli Ecotypes from West Java, Indonesia, by RAPD Analysis
Full text linkEchinochloa crus-galli (Barnyardgrass: Poaceae), is one of the most detrimental weeds in rice fields globally. As one of the leading rice producers in Indonesia, controlling barnyard grass in rice fields in West Java province is of great importance. Information on the genetic variability of barnyard grass is necessary to determine proper weed control. A molecular marker is considered the most accurate tool in determining genetic variability as its profile is unaffected by the environment. The objective of this study was to evaluate the genetic variability of barnyard grass collected from seven sub-districts in West Java province, Indonesia, using RAPD markers. Genomic DNA of barnyard grass ecotypes from “Bayusari”, “Majalaya”, “Klari”, “Cugenang”, “Cianjur”, “Ciomas”, and “Ciampea” sub-districts were analyzed using eight RAPD primers and resulted in a total of 87 reproducible amplicons. Of these amplicons, 59 were polymorphic, and 28 were monomorphic, with a polymorphism percentage ranging from 37.5-92.8%. Polymorphism information content (PIC) values ranged from 0.21 to 0.41, indicating the used RAPD markers are highly informative. All seven ecotypes were divided into three distinct groups with a coefficient level of 0.77 in a dendrogram constructed following the UPGMA clustering method. Group 1 consisted only of the “Bayusari” ecotype. Group 2 consisted of “Majalaya”, “Klari”, and “Cugenang” ecotypes, while Group 3 consisted of “Cianjur”, “Ciomas”, and “Ciampea” ecotypes. This research indicated remote dispersal of E. crus-galli, since ecotypes from distant locations were found to be closely relate
Biology of Cellulosic Bacteria from Hindgut Oryctes rhinoceros as Antagonistic Agent of Ganoderma boninense In Vitro
Full text linkGanoderma boninense is a pathogenic fungus that causes the base rot of oil palm trunks. Antagonistic microorganisms can inhibit, suppress, or eliminate populations of plant pathogens. Antagonistic microorganisms can be utilized through symbiotic bacteria. The capability of symbiotic bacteria to degrade cellulose enables them to be more utilized as biological agents for controlling plant pathogens. Oryctes rhinoceros larvae are one of the insects that have symbiotic bacteria. This study aims to analyze the morphological and biochemical characteristics of symbiotic bacteria of O. rhinoceros larvae and see their effectiveness in inhibiting the growth of G. boninense. This research employed a non-factorial completely randomized design with six treatments: S0, Ganoderma boninense (control); S1, G. boninense + isolate of symbiotic bacteria (P2); and S2, G. boninense + isolate of symbiotic bacteria (P3). The results showed that treatment P2 that c, which contains Bacillus subtilis, was able to inhibit G. boninense by 35.21%, and the P3 bacterial isolate, which is Bacillus sp., was able to inhibit the growth of G. boninense by 23.66%. The identification showed that bacteria P2 is B. subtilis, and P3 is Bacillus sp