Thai Journal of Agricultural Science

Spice essential oils enhance broiler gut health, performance, and oxidative stability

2024-12-10T16:31:53+07:00

Background and Objective: Optimizing gut health is critical for sustaining poultry productivity while reducing antibiotic use. This study evaluated the effects of garlic, turmeric, ginger, and cinnamon essential oils administered via drinking water on growth, intestinal morphology, oxidative stability, and gut microbial population in broiler chickens.
Methodology: A total of 200 a-day-old Arbor Acres broiler chicks weighing 38.47 ± 1.47 g were randomly distributed into five groups with control (CON), garlic essential oil (GAR), ginger essential oil (GIN), turmeric essential oil (TUR), and cinnamon essential oil (CIN), with ten replicates of four birds each, over a 42-day trial. Birds received a basal diet with essential oils in the drinking water. Growth indices, microbial counts, intestinal histomorphometry, and antioxidant status were evaluated using one-way ANOVA (P < 0.05).
Main Results: GAR and CIN significantly improved final body weight and villus height in duodenum compared with CON, while TUR resulted in the lowest growth performance and poorer feed efficiency. Essential oil treatments increased feed intake, particularly in GAR, without consistent improvement in feed conversion ratio. GAR reduced cecal pathogenic bacteria (coliforms and enterococci) while maintaining Lactobacillus populations, whereas TUR non-selectively increased both beneficial and non-beneficial microbes. GAR and GIN significantly enhanced intestinal antioxidant activity, and all treatments reduced lipid peroxidation in the duodenum and jejunum.
Conclusions: Supplementation of spice essential oils via drinking water improves gut health, oxidative stability, and growth performance in broilers, with garlic and cinnamon showing superior growth-promoting effects and ginger and garlic enhancing antioxidant capacity. These findings suggest that spice essential oils may have potential as phytogenic supplements capable of supporting broiler performance and intestinal health.

Effect of seed pelleting on seed quality and seedling growth of small seed of maize

2025-04-19T06:42:56+07:00

Background and Objective: Small-sized maize seeds are often less preferred by farmers because of their lower vigor and poorer field establishment, resulting in reduced utilization and economic losses. This study evaluated the effectiveness of different pelleting materials in improving the physical and physiological quality of small seeds of maize (Zea mays L.) inbred line Tak Fa 1.
Methodology: The experiment was conducted at the Khon Kaen Seed Research and Development Center and the Nakhon Sawan Field Crops Research Center from May 2023 to July 2024. Maize seeds were classified into small (16/64 inch), medium (18/64 inch), and large (20/64 inch) size classes. Small seeds were pelleted using hydroxypropyl methylcellulose as a binder with bentonite, vermiculite, talcum, or pumice as filler materials. Unpelleted small, medium, and large seeds served as controls. Laboratory experiments were arranged in a completely randomized design, while field experiments followed a randomized complete block design with four replications. Seed physical traits, germination, vigor, field emergence, and seedling growth were evaluated.
Main Results: Pelleting increased seed size from 16/64 inch to approximately 18/64 inch and improved seed uniformity. Germination remained high under both laboratory and field conditions, indicating that pelleting did not adversely affect seed viability. Bentonite- and vermiculite-pelleted seeds exhibited significantly greater vigor than unpelleted small seeds, as evidenced by higher germination after accelerated aging and faster emergence under field conditions. These materials also improved seedling establishment and overall field performance. Talcum and pumice promoted early seedling growth but were less effective in maintaining seed vigor under aging stress.
Conclusions: Bentonite and vermiculite were the most effective pelleting materials for improving seed size, vigor, stress tolerance, and field establishment of small Tak Fa 1 maize seeds. Seed pelleting enhanced the value and utilization of small seeds without compromising seed quality, resulting in performance comparable to commercially accepted seed grades.

Indigenous knowledge in crop management for reducing papaya ringspot disease incidence

2024-10-08T17:11:15+07:00

Background and Objective: Papaya ringspot virus (PRSV) is a major constraint on commercial papaya (Carica papaya L.) production. This study evaluated chemical-free indigenous barrier cropping systems to suppress PRSV incidence and severity while optimizing fruit yield for smallholders in Thailand.
Methodology: A field experiment using a randomized complete block design with five treatments and five replications was conducted in Maha Sarakham province. Papaya plots (2.5 m × 2.0 m spacing) were surrounded by double-row living barriers of different companion crops positioned 3.0 m away. Evaluated treatments included papaya bounded by: (1) banana (Musa ABB group), (2) custard apple (Annona squamosa L.), (3) cassava (Manihot esculenta), (4) sugarcane (Saccharum officinarum), and (5) a monoculture control. Yield, fruit quality, total soluble solids (°Brix), PRSV incidence (%), and severity scores (0–4 scale) were monitored. Mean separation was performed using Duncan's multiple range test (P < 0.05).
Main Results: Integrated barriers significantly mitigated viral impacts and enhanced yields compared to the control (P < 0.05). The control exhibited maximal disease pressure, recording 100.00 ± 0.00% incidence and a 3.92 ± 0.11 severity score. Sugarcane and custard apple barriers minimized incidence to 61.04 ± 6.90% and 53.12 ± 7.20%, and severity to 2.37 ± 0.28 and 2.44 ± 0.25, respectively. The banana boundary system demonstrated the highest agronomic performance despite an 88.61 ± 9.45% incidence and 3.15 ± 0.38 severity score. It produced the highest fruit count (130.62 ± 18.45 fruits/tree), mean weight (2.30 ± 0.35 kg), flesh thickness (3.40 ± 0.42 cm), and peak sweetness (16.00 ± 1.50 °Brix) over the control.
Conclusions: Diversified polyculture provides a viable non-chemical strategy for PRSV suppression. Sugarcane and custard apple systems likely serve as physical/visual vector barriers. Meanwhile, the banana model potentially provides agroecological modifications supporting crop vigor under disease pressure.

Automated seedling vigor estimation in cucumbers using digital image processing

2026-04-01T16:28:51+07:00

Background and Objective: Farmers often rely on experience rather than quantitative indicators to determine seedling quality, resulting in inefficiencies in resource allocation. This study aimed to (1) compare seedling vigor and growth characteristics between open-pollinated (OP) and F1 hybrid cucumber seed types, and (2) develop a non-destructive predictive model for seedling vigor estimation based on digital image analysis.
Methodology: Seedling images were acquired under controlled LED lighting using a 5 MP digital camera positioned 30 cm above 14-day-old seedlings. A YOLOv8-based object detection model was applied to detect and isolate true leaf regions, from which pixel count and RGB color values were extracted as input features for a multiple linear regression model to predict the seedling vigor index (SVI).
Main Results: The YOLOv8 object detection model achieved a mean average precision (mAP@0.5) of 96.00%, precision of 93.40%, and recall of 94.40% in detecting true leaves. Multiple linear regression analysis was conducted using the Scikit-learn library in Python. Scikit-learn provides regression-based machine learning algorithms, including multiple linear regression. The equation was then applied to the training and test sets, using the pixel values of true leaves as the independent variable and SVI as the dependent variable. Using multiple regression analysis, the trained model generated the equation SVI = -2.27 + (2.84 × 10^-5× pixel) + (3.48 × 10^-5× R) + (-7.49 × 10^-2 × G) + (2.06 × 10^-1× B), R² = 0.57 and RMSE = 1.10. The model achieved the test set, r = 0.79 and RMSE = 1.34. The model performance showed a correlation coefficient of 0.85 for OP data and 0.91 for F1 hybrid data.
Conclusions: The results demonstrate that digital image processing combined with object detection provides a non-destructive and effective approach to estimate seedling vigor quality. The predictive models developed from OP and F1 hybrid datasets indicate potential application in precision agriculture for automated seedling quality assessment and transplanting decision support.

Biochar and poultry manure impacts on soil characteristics and yam productivity in a degraded tropical Alfisol

2026-01-14T09:51:00+07:00

Background and Objective: Soil degradation remains a significant constraint to sustainable production of white yam (Dioscorea rotundata Poir) in tropical regions, largely due to continuous cultivation and progressive nutrient depletion. While organic amendments like biochar and poultry manure have been studied in cereal and vegetable systems, their combined effects on yam-based systems remain underexplored. This study evaluated the effects of cocoa pod husk biochar (CPHB) and poultry manure (PM) on soil properties, leaf nutrient concentrations, growth, and tuber yield of yam grown on a degraded Alfisol in Owo, southwestern Nigeria.
Methodology: A two-year (2023–2024) field experiment was conducted at Owo using a factorial randomized complete block design (RCBD) comprising three CPHB rates (0, 15, and 30 t ha^-1) and three PM rates (0, 10, and 20 t ha^-1), replicated three times. Soil physical and chemical properties, leaf nutrient concentrations, growth parameters, and tuber yield were evaluated following standard procedures.
Main Results: Results showed that CPHB and PM, applied singly or together, significantly (P < 0.05) improved soil properties compared with the control. The combined application of 30 t ha^-1 CPHB and 20 t ha^-1 PM resulted in the lowest bulk density (0.90 Mg m^-3), highest total porosity (66.3%), moisture content (19.5%), organic matter (3.58%), total nitrogen (0.21%), available phosphorus (18.7 mg kg^-1), and exchangeable K (0.33 cmol kg^-1). Leaf N, P, K, Ca, and Mg concentrations, growth, and yield attributes also increased. Averaged over two years, the highest tuber yield (46.1 t ha^-1) was recorded with 30 t ha^-1 CPHB + 20 t ha^-1 PM, representing 35–82% yield increases over other treatments.
Conclusions: CPHB and PM produced significant interaction effects on soil fertility, nutrient uptake, and yam yield on degraded Alfisols. Their combined application offers a sustainable approach for restoring soil productivity and improving yam production in tropical agroecosystems.

Slower ripening and enhanced antioxidant retention: Effects of crude bacterial IAA and temperature phasing on postharvest quality of ‘Kluai Khai’ (Musa acuminata, AA Group) bananas

2026-06-27T16:02:36+07:00

Background and Objective: Postharvest deterioration after ripening severely limits the marketability of 'Kluai Khai' banana (Musa acuminata, AA group). This study evaluated whether an indole-3-acetic acid (IAA)-containing, cell-free solution produced by Micrococcus yunnanensis P2-23 and temperature phasing (TP) could maintain postharvest quality.
Methodology: A 4 × 2 factorial completely randomized design with three biological replicates combined with four nominal Salkowski-estimated IAA-equivalent concentrations (0, 250, 500, and 1,000 ppm) with non-TP and TP regimes. After a 3-min dip and storage at 12 ± 2°C for 14 days, fruit were ripened either continuously at 25°C or under TP (25, 22, 20, and 18°C on days 1–4, respectively, followed by 25°C). Visual quality, physicochemical characteristics, CO₂ production, and antioxidant-related attributes were evaluated through day 10.
Main Results: All fruits were fully yellow by day 6, with no treatment differences in final total soluble solids. By day 10, TP-treated fruit had brighter peel, higher titratable acidity and firmness (118.0–132.7 versus 56.9–66.6 N), and lower weight loss (5.55–7.03 versus 8.28–9.13%) than non-TP fruit. The 1,000 ppm crude solution under TP maintained visual acceptability four days longer than the untreated non-TP control. TP also maintained higher late-stage ferric-reducing antioxidant power and total phenolic content, whereas non-TP fruit had higher DPPH activity. Respiration and crude-solution effects varied with time and concentration, with no consistent additional benefit or general synergy. HPLC-measured authentic IAA was 43.86% of the Salkowski estimate.
Conclusions: TP most consistently slowed late-stage deterioration without disrupting ripening and is therefore the best-supported practical treatment for ‘Kluai Khai’ bananas. The crude bacterial solution provided no consistent additional benefit, and its effects cannot be assigned solely to IAA because authentic IAA was lower than the Salkowski estimate and other metabolites may have been present.