Agriculture and Natural Resources

Simulation and experimental study of biocoal production via dry torrefaction of palm empty fruit bunch

2025-04-01T16:28:40+07:00

Importance of the work: The optimum conditions of biocoal and techno-economic analysis are important in determining the potential of biocoal production based on a torrefaction.

Objectives: 1) To experiment with torrefaction for simulation; 2) to simulate and design biocoal production; and 3) to perform techno-economic analysis.

Materials & Methods: A palm empty fruit bunch (PEFB) sample from Thailand was used in the torrefaction experiment. The simulation used the Aspen Plus to model the torrefaction. Investment and optimization aimed to maximize profitability. The torrefaction temperature was set at 200-300°C, with a heating rate of 10°C/min and a residue time of 10-50 min.

Results: The yield of biocoal from PEFB at 300°C and a residue time of 30 min was 56.13%, which was higher than the biogas and bio-oil yields. There was a good correlation between the PEFB yield and the temperature factor at 300–320°C, suggesting that this temperature range influenced the yield of PEFB, making it a suitable biomass material for making biocoal. The simulation generated 1,876.25 t/d of PEFB at 300°C, producing 21,631.70 kg/hr of char, 14,530.29 kg/hr of gas, 1,279.31 kg/hr of bio-oil and 40,736.10 kg/hr of vapor. The optimal utility cost was USD 4.06 million, with a 20 yr life cycle and a total capital investment of USD 20.38 million.

Main finding: In the simulation using PEFB, the production of biocoal decreased with increasing temperature due to faster devolatilization and a reduction in carbon levels. The conceptual design of biocoal production was presented with supported data from experiments and techno-economic analysis.

Extending the shelf life of organic liquid fertilizer from food waste processing based on Masaro technology

2025-04-01T22:18:20+07:00

Importance of the work: Food waste is an environmental issue in Indonesia that requires greater attention. One effort to address the problem is ‘Masaro’ (an abbreviation for “zero waste management” in Indonesian) technology, with its main product being organic liquid fertilizer. However, this fertilizer can experience pH escalation due to deterioration when it is oxidized. Therefore, a solution is needed to prolong its shelf life.

Objectives: To extend the shelf life of organic liquid fertilizer from food waste using Masaro technology.

Materials and Methods: Several types of food waste were chopped and then fermented in two stages to form a product. Variations were investigated in the organic waste type, the addition of phosphate buffer and the product storage conditions.

Results: The organic waste producing the highest pH (6-8) was mustard greens due to their carbohydrate content being the lowest. Phosphate buffer addition significantly maintained the pH levels at 3-4 for all food waste types, as well as enhancing the number of probiotic bacteria, reducing the presence of pathogenic bacteria and increasing the nutrient contents (amino acids and fatty acids) in the product. The optimal storage conditions for the liquid fertilizer produced were a temperature of 8-10°C without exposure to direct sunlight. On the other hand, high temperatures and greater light exposure expedited oxidation.

Main finding: The application of phosphate buffers, storage at low temperatures and no sunlight exposure significantly reduced fertilizer deterioration through oxidation. These findings should help to ensure the shelf life extension of organic liquid fertilizer to longer than 1 yr.

Impacts of α-tocopherol (vitamin E) and L-ascorbic acid (vitamin C) on reproductive performance in female yellow mystus (Hemibagrus spilopterus)

2025-04-02T09:00:53+07:00

Importance of the work: The success of breeding in fish is influenced by egg quality, which can be enhanced through vitamin supplementation in the diet.

Objectives: To evaluate the effects of vitamins C and E, both individually and in combination, on the growth, reproductive performance and sex hormone levels in female yellow mystus.

Materials and Methods: Female yellow mystus aged 1 yr were fed a commercial diet with 32% protein, supplemented with: 1) no vitamins (the control); 2) vitamin C at 1,000 mg/kg; 3) vitamin E at 500 mg/kg; or 4) a combination of 1,000 mg/kg vitamin C + 500 mg/kg vitamin E. Data were collected on growth, ovary weight, gonadosomatic index (GSI), fecundity and hormone levels after 30 d and 60 d of treatment, while the fertilization rate and the hatching rate were evaluated only at 60 d.

Results: There were synergistic effects from adding vitamin C and E. Fish fed the combined vitamin supplementation showed improved GSI, ovary weight, estrogen and progesterone levels. Vitamin C supplementation alone (at 30 d) also increased fecundity. By day 60, all vitamin-supplemented groups showed improved fecundity, fertilization and hatching rates.

Main finding: The combination of vitamin C and vitamin E significantly improved reproductive parameters in yellow mystus, consisting of fecundity, fertilization rates, hatching rates and sex hormones, offering potential for enhanced fry production.

Non-destructive method for whole-egg freshness inspection in food manufacturing

2025-04-02T09:24:52+07:00

Importance of the work: Expired eggs can ruin an entire batch in the food industry; however, under current practice, only a subset of the eggs is randomly tested for freshness.

Objectives: To develop a non-destructive testing method for full egg-freshness inspection based on the analysis of the yolk movement speed.

Materials and Methods: Experiments were conducted on eggs from three farms, with storage periods ranging from 1 to 14 days. The inspection apparatus incorporated image processing with the traditional candle testing method and consisted of egg holder hardware and a vision system. A camera was used to capture yolk images that were subsequently used to calculate the yolk movement speed. From the literature review, it was found that the viscosity of egg whites decreases as the storage duration of eggs increases. Consequently, the egg yolk moves more rapidly over time. This study utilizes this principle to assess the freshness of eggs.

Results: The storage period increased the average yolk movement speed. With storage for up to 6 d, the yolk movement speed of the tested eggs was similar (16.3 mm/s on average), to 7–8 d of storage (25.4 mm/s), with a slight increase after 9–13 d. After 14 d of storage, the average yolk movement speed was 31.4 mm/s or approximately twice that of the fresh eggs. The results were verified based on other benchmarked methods.

Main finding: The proposed method was verified as a non-destructive method for egg-freshness inspection. A full-inspection system could be developed and integrated into the manufacturing process.

Effect of abiotic feeding factors on mineral metabolism in bulls

2025-04-02T09:27:21+07:00

Importance of the work: The study of the combined effects of the wormwood plant (Artemisia absinthium L.) and trace elements is crucial for understanding their impact on cattle metabolic systems.

Objectives: To evaluate the effect of Artemisia absinthium L. and cobalt chelate compounds on the metabolic parameters and mineral metabolism of bulls.

Materials and Methods: The study was undertaken at the Federal Scientific Center for Biological Systems and Agrotechnology of the Russian Academy of Sciences using a sample of 16 Kazakh bulls (white-headed breed, aged 13-14 mth). The experiment used a 4 × 4 Latin square design, comprising four repetitions with four bulls per group, across 17 d periods (10 d of adaptation and 7 d of sampling). Blood samples were collected during each sampling period to determine biochemical indicators and trace elements. Biochemical analyses were performed using an automatic biochemical analyzer, while trace element levels in serum were assessed using inductively coupled plasma spectrometry.

Results: Alterations in feeding conditions significantly affected the metabolism of the Kazakh white-headed bulls. During the experimental period, incorporating a plant-based feed supplement derived from Artemisia absinthium L. was an optimal strategy for enhancing metabolic processes and promoting growth in the bulls. The combined introduction of wormwood and cobalt compounds into the diet resulted in increases in the levels of cobalt (Co) by 67% (p = 0.002), chromium by 80% (p = 0.004) and selenium by 12% (p = 0.05). Furthermore, when Co compounds were administered alone, there was a notable increase in Co levels by 100% (p = 0.002), accompanied by a decrease in iodine levels by 33% (p = 0.007). Additionally, groups receiving wormwood supplements had increased concentrations of heavy metals (nickel and lead) exceeding 10%.

Main finding: Feeding a plant-based additive comprising Artemisia absinthium L. and cobalt chloride (CoCl₂) compounds was optimal for cattle. This combined supplementation effectively enhanced protein, carbohydrate, lipid and mineral metabolism in the bulls.

Differential performance in height growth rate and yield components to enhance cane yields of various sugarcane types during early drought and post-recove

2025-04-02T09:39:12+07:00

Importance of the work: Drought stress reduces sugarcane yields. A deeper understanding of the growth and yield components across different sugarcane genotypes could improve the process of breeding sugarcane with tolerance to drought.

Objectives: To investigate the effects of various water regimes on the growth behavior, yield components and cane yield of different sugarcane genotypes.

Materials and Methods: The experiment was designed as a split plot in a randomized complete block design with three replications. The main plot involved two water regimes—(well-watered (WW) and early drought stress (DS) —during 2–6 mth after tillering (MAT; tillering and early stalk elongation phase). The subplot contained six diverse sugarcane genotypes. The stalk height was measured at 3, 6, 8, 10, and 12 MAT. The height growth rate (HGR) and stalk number per stool were recorded at 6, 8, 10, and 12 MAT. The cane yield and yield components were collected at harvest.

Results: Early drought reduced the cane yield, stalk length, single stalk weight and millable cane. Based on the cane yield, F03-362 (F1), KK09-0358 (BC1) and KK3 (commercial cane) were identified as drought-resistant genotypes. The high number of millable canes and plant height were important traits that promoted high cane yield in F03-362, while KK09-0358 and KK3 were derived from a medium number of millable canes and a high single stalk weight.

Main finding: HGR, during recovery periods (re-watered after 6 MAT until 12 MAT), impacted promoting cane yield. The drought-tolerant genotypes had greater values for HGR than the drought-susceptible genotypes. This perspective was beneficial as it emphasized the selection characteristics in sugarcane breeding efforts to enhance drought tolerance.

in vitro Effect of organic acid combinations on sporulation of Eimeria tenella

2025-04-02T09:55:07+07:00

Importance of the work: Organic acids show potential for inhibiting Eimeria tenella that causes chicken coccidiosis with diarrhea and weight loss; however, there is no available specific efficacy data.

Objectives: To evaluate citric acid and formic acid, both individually and combined, as well as a commercial product (known as Bluetec) for in vitro inhibition of E. tenella.

Materials and Methods: E. tenella oocysts were identified using morphology and polymerase chain reaction. The half maximal inhibitory concentration (IC50) for sporulation inhibition was determined by exposing oocysts to citric and formic acids at various concentrations. Trials consisted of citric acid, formic acid, their combination and Bluetec, with sporulation inhibition assessed after 24 hr and 48 hr by counting unsporulated and sporulated oocysts.

Results: The IC50 values were 4.33 mg/mL for citric acid and 2.40 mg/mL for formic acid. After 24 hr of incubation, the sporulation inhibition (SI) percentages were 2.95% for the 3% diclazuril (PC), 12.07% for citric acid, 8.50% for formic acid and 15.13% for the combination and 48 hr of incubation were 21.49%, 11.34% and 23.51%, respectively. Incubation for 48 hour resulted in a reduced sporulation percentage, indicating that the inhibition of sporulation was dependent on the duration of exposure. The SI percentages were 0% for distilled water, 7.96% for PC and 29.74% for Bluetec, highlighting significant differences among the tested items and suggesting a synergistic effect between citric and formic acids.

Main finding: Combining citric acid and formic acid, as well as using Bluetec effectively inhibited E. tenella sporulation. There was a notable synergistic effect of citric and formic acids, though its mechanism remained unclear. The most effective treatments were citric and formic acids with incubation for 48 hr and Bluetec with incubation for 24 hr. These organic acids could be utilized as food additives or disinfectants in poultry production.

Enhancing the control efficiency of plant extracts against Spodoptera frugiperda (Lepidoptera: Noctuoidea) through mixture formula development

2025-04-02T09:59:32+07:00

Importance of this work: The fall armyworm, Spodoptera frugiperda, is a major agricultural pest, requiring effective and sustainable control methods. This study enhances control efficiency by developing a plant extract mixture that significantly increases mortality while reducing the required dosage.

Objectives: To assess the insecticidal potential of various plant crude extracts against S. frugiperda larvae for the future development of effective insecticide products.

Materials and methods: The insecticidal potential was investigated of various crude extracts from Cyperus rotundus mixed with Piper retrofractum against S. frugiperda larvae. The acute effects were determined of binary mixtures of various compounds at concentrations equal to the doses required to kill 30%, 20% and 10% of the tested population after the specified test duration (24 hr or 48 hr).

Results: The best formulation was the combination of P. retrofractum hexane crude extract (at a dose of 10.57 parts per million, ppm) and C. rotundus dichloromethane extract (at a dose of 2,504 ppm), which caused mortality rates of up to 98% compared with 20% when the individual extracts were used.

Main finding: This mixture formulation allowed the use of smaller amounts of plant substances, resulting in lower production costs. This information should be useful for the future development of effective insecticide products.

Identification and fungicide sensitivity of Phytophthora nicotianae for controlling pineapple heart rot in Thailand

2025-04-02T14:26:02+07:00

Importance of the work:

This research identified Phytophthora nicotianae as the cause of pineapple heart rot and evaluated fungicide efficacy for control.

Objectives:

To identify and characterize Phytophthora isolates, evaluate fungicide sensitivity and assess fungicide effectiveness in pineapple field trials.

Materials and Methods:

Pineapple heart rot samples were collected for pathogen isolation. Phytophthora isolates were identified using morphological and molecular methods. Fungicide sensitivity was evaluated based on in vitro assays, with field trials being used to assess the efficacy of four fungicides. Disease incidence and severity were monitored and analyzed using two-way analysis of variance.

Results:

Four fungal isolates (PHY-01 to PHY-04) were identified, with PHY-02 matching Phytophthora nicotianae morphologically and phylogenetically. Pathogenicity assays confirmed PHY-02 as the causal agent of pineapple heart rot. In fungicide sensitivity tests, dimethomorph achieved 100% mycelial growth inhibition at concentrations of 100 mg/L and 1,000 mg/L, with a half maximal effective concentration (EC₅₀) value of 0.17 mg/L. Metalaxyl was effective at higher concentrations (EC₅₀: 5.3 mg/L). Fosetyl-Al and phosphonic acid showed no efficacy. The field trials demonstrated that dimethomorph (9.5 mL/L) was most effective, reducing disease severity to 1 after 45 d, compared to 3 in control plots. Metalaxyl and fosetyl-Al provided moderate control, while phosphonic acid was less effective.

Main finding:

Phytophthora nicotianae was confirmed as the cause of pineapple heart rot. The results demonstrated dimethomorph's superior efficacy for disease control, advancing effective fungicide use and integrated management strategies for pineapple cultivation.

Fungicide resistance in Colletotrichum species causing durian anthracnose in eastern Thailand

2025-04-02T14:34:46+07:00

Importance of the work: Durian (Durio zibenthinus Murr.) is one of the most popular and exceptionally high-value fruit crops globally. Colletotrichum species are the causal pathogens of durian anthracnose, making managing fungicide resistance in the field mandatory.

Objectives: To evaluate the sensitivity of Colletotrichum species on various fungicides currently used in durian orchards in eastern Thailand.

Materials and Methods: In total, 15 Colletotrichum isolates were tested for sensitivity to several fungicide classes: Quinone outside Inhibitors (QoIs), DeMethylation Inhibitors (DMIs) and multi-site fungicides were tested on culture medium at concentrations of 0.1, 1, 10, 100 and 1,000 µg/mL. The 50% mycelial growth inhibition (EC₅₀) was analyzed and used to classify sensitive or resistant phenotypes. The selected isolates were evaluated for their fungicide sensitivity to spore germination and on detached durian leaves.

Results: In all 15 tested Colletotrichum isolates, the mycelial growth was sensitive to difenoconazole and prochloraz (EC₅₀ range of 0.02–45.5 µg/mL). Additionally, the EC₅₀ values varied significantly for pyraclostrobin (0.09 to over 100 µg/mL). Of these isolates, six showed sensitivity to pyraclostrobin. Unfortunately, 11 and 6 isolates exhibited resistance to chlorothalonil and mancozeb, respectively. Furthermore, both pyraclostrobin and mancozeb exhibited similar sensitivity phenotypes in mycelial growth and spore germination inhibition across all tested isolates. Notably, difenoconazole had higher EC₅₀values (74.42–316.75 µg/mL) to spore germination inhibition. Pyraclostrobin, difenoconazole and mancozeb effectively controlled disease severity in sensitive isolates on detached durian leaves. In contrast, these fungicides had no effect on the fungicide-resistant isolates.

Main finding: A population of Colletotrichum resistant to pyraclostrobin, chlorothalonil and mancozeb was identified in durian orchards. Fortunately, the pathogen remains susceptible to two other fungicides (difenoconazole and prochloraz). Thus, these latter two fungicides should be recommended for use or rotation with other mode-of-action fungicides in the anthracnose disease management program for durians in eastern Thailand.

Development of organic medium from agricultural by-product for cultivation of romaine lettuce

2025-04-02T14:51:29+07:00

Importance of the work: The development of an organic growth medium can promote sustainability in lettuce (Lactuca sativa L.) cultivation; however, costs remain an issue in developing countries.

Objectives: To develop an optimal growth medium using compost from local organic sources for lettuce cultivation and to investigate the effects of heat treatment.

Materials and Methods: Coir, charcoal, manure, soybean meal, molasses and rice bran were composted with fish bio-extract. The dry medium was produced via heating and regenerated using fish bio-extract. A completely randomized design was used for the lettuce growth experiment. The performance was evaluated of compost, dry and regenerated media and topsoil.

Results: The compost medium had better nutrient profiles and microbial counts than common topsoil and commercial soil products, which led to improved lettuce growth. Heating the compost at 105°C significantly reduced the bulk density and the nitrogen content in the dry medium. The regeneration of the medium with the fish bio-extract increased the nitrogen content to the level of the compost medium and significantly restored the microorganism count. When used in romaine lettuce cultivation, the regenerated medium improved lettuce growth parameters, (plant height and width, fresh and dry weights) equal to those of the lettuce grown in the compost medium.

Main finding: An accessible method was identified for producing inexpensive and an effective organic growth medium for lettuce cultivation. The heat treatment reduced the bulk density, microorganism count and nitrogen content; however, these could be restored via treatment with fish bio-extract.

Design and synthesis of resin-attachable spatane analog for prevention of sea urchin-induced seaweed loss

2025-04-02T14:58:22+07:00

Importance of the work: This study addresses a critical environmental issue with an innovative, potentially sustainable solution. By providing hope for restoring essential coastal ecosystems, it underscores the potential positive impact of research on the environment.

Objectives: To create a new spatane-type diterpenoid analog for attachment to polymers to prevent rocky-shore denudation.

Materials and Methods: The strategy utilized the method of Salomon et al. (1991) to build a spatane framework and then transform it into a target non-natural compound, as an innovative approach in the field. The methodology involved altering the spatane framework to include a methylene chain featuring a terminal alkyne, which should be of interest to researchers.

Results: A [2+2] photocycloaddition reaction was achieved between 3-methylcyclopent-2-en-1-one and (1R*,2R*,4R*)-bicyclo[2.2.1]hept-5-en-2-yl acetate to construct the core structure of the spatane diterpenoid. This reaction was efficient and laid the foundation for subsequent modifications. Through a series of reactions, including Jones oxidation, Baeyer-Villiger oxidation, and reduction using DIBAL, the key intermediate compound (23) was synthesized successfully, containing the desired spatane framework and a functional group suitable for further transformation.

Main finding: The spatane core structure was synthesized successfully and efficiently via a [2+2] photocycloaddition reaction, demonstrating the feasibility of creating a novel spatane-type diterpenoid analog to deter sea urchin grazing, instilling confidence in potential further related research.

Characteristics of halophilic lactic acid bacteria isolated from fermented snakehead fish (Channa striata Bloch)

2025-04-02T15:01:32+07:00

Importance of the work: This work lays the groundwork for further exploration into the use of halophilic lactic acid bacteria (LAB) in developing high-quality fermented fish products.

Objectives: To isolate and characterize halophilic LAB isolated from fermented snakehead fish (Channa striata Bloch), a traditional Vietnamese ‘mam’ product.

Materials and Methods: Fermented snakehead samples were collected from local markets and transported to the laboratory under sterile conditions. The fish samples were homogenized in saline solution and serially diluted. Halophilic LAB were isolated by plating onto Man Rogosa Sharpe agar supplemented with 5% NaCl, followed by anaerobic incubation at 30°C for 48 hr. Strains were evaluated for their growth ability in de Man, Rogosa, Sharpe medium containing varying concentrations of NaCl (5–15%), at varying growth temperatures (30–45°C), as well as for their levels of proteolytic activity.

Results: In total, 18 LAB strains were isolated from 4 fermented snakehead samples, with identification performed using 16S rRNA gene sequencing. The strain with superior properties, identified as Tetragenococcus halophilus, had signifcant proteolytic activity, crucial for enhancing the flavor and nutritional profile of fermented fish. The isolated strains demonstrated robust growth in high-salinity conditions, specifically at 10% NaCl, with optimal growth observed at 30°C and 35°C. Additionally, most strains had high levels of protein hydrolysis.

Main finding: The halophilic LAB Tetragenococcus halophilus FF18.2 was successfully isolated and screened. Due to its ability to thrive in high-salt environments and degrade proteins, the addition of this bacterial strain as a starter culture may contribute to the development of high-quality, safe and potentially more nutritious fermented fish products.

Effects of corn malt on rumen fermentation, blood metabolites and growth performance in fattening goats

2025-04-02T16:21:49+07:00

Importance of the work: Corn malt (CM), derived from fermented corn grain, has the potential to improve ruminant feed quality and enhance growth.

Objectives: To evaluate the effects of different CM and fermented corn husk (CH) ratios on rumen fermentation, blood metabolites and growth performance in fattening goats.

Materials and Methods: In total, 20 male crossbred Native × Boer goats (13.0 ± 4.0 kg initial body weight) aged 3 mth were randomly assigned to five total mixed ratio (TMR) diets: T1 = 50% corn grain (CG) + 50% CH; T2 = 50% CM + 50% CH; T3 = 60% CM + 40% CH; T4 = 70% CM + 30% CH; and T5 = 80% CM + 20% CH. A completely randomized design was applied for the 90 d trial. The parameters measured were: rumen pH, volatile fatty acids (VFA), ammonia-nitrogen (NH₃-N), blood urea nitrogen (BUN), blood glucose, insulin, body weight gain (BWG), average daily gain (ADG), feed conversion ratio (FCR) and feed intake (FI).

Results: The rumen pH, VFA, NH₃-N and BUN levels were within their optimal ranges across treatments. The CM-based diets (T2–T5) produced higher blood glucose levels (p < 0.01) than T1. Goats fed T5 produced the highest BWG (12.97 kg), ADF (0.21 kg/day) and FI (1.38 kg/day), representing a 75% increase in ADG over T1. FCR was similar across treatments; however, higher CM inclusion enhanced nutrient utilization and feed palatability.

Main finding: The TMR diet with 80% CM and 20% CH (T5) significantly improved growth performance and feed efficiency, suggesting its potential as a cost-effective strategy for fattening goats. Further studies are needed to validate its use in other ruminant species and diverse environments.

Laboratory bioassays of volatile pyrethroid spatial repellents against medically important mosquitoes in the Asia-Pacific region: A systematic review

2025-04-02T14:47:39+07:00

Importance of the work: Variations were identified in laboratory evaluation studies of volatile pyrethroid spatial repellents (VPSRs) in the Asia-Pacific region (APR).

Objectives: To conduct a systematic review of laboratory studies of VPSR efficacy in the APR and their adherence to World Health Organization (WHO) guidelines.

Materials and Methods: The search occurred between May 2023 until September 2024. Studies were identified by searching electronic databases and were screened using defined criteria. Strengths and weaknesses were identified of studies according to WHO guidelines and the relevant published literature. Critical comments were included on evaluation methods, design, and mosquito rearing conditions.

Results: Since 2004, VPSR studies in the APR have focused on toxic effects, as reflected by their chosen evaluation methods. Laboratory studies measured common entomological endpoints such as knockdown rate, knockdown time, and mortality. There was minimal variation in protocol due to unique study objectives. However, mosquito rearing conditions and physiological status in some studies did not adhere to WHO guidelines. This could be attributed to the unique main objectives and resources of each study. In addition, three-room chamber studies emphasized the importance of airspace volume and the capabilities of secondary devices in vaporizer formulations when conducting efficacy studies in this test arena.

Main finding: Individual VPSR studies in the APR appeared to be unique. Engagement of other APR countries would be beneficial to provide preliminary picture of efficacy against medically important mosquitoes and to support further semi-field and field studies.