Thai Journal of Agricultural Science

Evaluation of lentil (Lens culinaris ) performance under different fertilizer application and irrigation regimes

Ahmed Bdaiwi Hussein — 2026-04-20

Background and Objective: The scarcity of water resources in semi-arid regions necessities the use of climate-smart methods like supplemental irrigation and soil amendments. This research aimed to investigate the effects of different fertilizers under both rainfed and supplemental irrigation conditions on the growth and yield of lentil in northwest Iran.
Methodology: A split-plot experiment was conducted with three replications under field conditions. The main factor was irrigation regimes, including rainfed (R) and supplemental irrigation (SI). SI was applied during the tillering, flowering, and seed setting stages. The subplots were allocated to various fertilizers: 1- no-fertilizer application (control), 2- the application of 100% of the recommended dose of three essential macronutrients (NPK₁₀₀), 3- the application of 50% of the recommended dose of NPK + 5 t ha^-1 of cattle farmyard manure (NPK₅₀+FYM₅), 4- the application of 50% of the suggested dose of NPK + biofertilizer (NPK₅₀+BI), 5- utilization of 10 t ha^-1 of FYM (FYM₁₀), and 6- the application of 20 t ha^-1 of FYM (FYM₂₀).
Main Results: SI significantly increased (P < 0.05) plant height (34.70 ± 3.03 cm), leaf greenness (48.45 ± 2.56 SPAD units), canopy width (20.58 ± 3.16 cm), biomass (0.97 ± 0.10 g), pod number (65.17 ± 5.51 pods per plant), and grain yield (7.59 ± 0.53 g) over the R conditions. The highest lateral and longitudinal canopy growth, as well as grain yield, were obtained by the application of FYM₁₀, FYM₂₀, and NPK₁₀₀. The application of all doses of NPK fertilizer increased the leaf greenness (SPAD index). The highest grain yield was recorded with the application of FYM₂₀, NPK₁₀₀, and FYM₁₀ under SI conditions.
Conclusions: SI enhanced the efficacy of chemical fertilizers and cattle farmyard manure. Consequently, it is crucial to applyorganic soil amendments and adhere to the suggested amounts of NPK, while also delivering three additional irrigations throughoutthe reproductive phases in the examined semi-arid agricultural zone.

School garden programs supporting sustainable agricultural intensification through knowledge transfer and family engagement

Channaty Ngang — 2026-04-20

Background and Objective: This study explores the role of a school garden program in facilitating the transfer of information on Sustainable Agricultural Intensification (SAI) from students to their families. The study investigates three key objectives: (1) assessing whether students shared SAI-related knowledge with their families and explore how parental demographic were related to receiving knowledge from their child, (2) exploring the types of SAI technologies parents reported hearing from their child and the benefits they expected after receiving that knowledge, and (3) analyzing the factors that influence parent’s willingness to apply SAI at home.
Methodology: This research was conducted in Siem Reap province, Cambodia, and involved 120 families. Data were collected through face-to-face interviews in June 2024. Data were analyzed using descriptive statistics, chi-square tests, independent t-tests, and logistic regression models.
Main Results: The results show that 70% of parents received SAI-related information from their child. Parents’ gender (χ²= 9.30, P= 0.002), occupation (χ² = 5.09, P = 0.024), and farming experiences (t = 2.72, P = 0.007) were significantly associated with their child sharing knowledge with them. Among the families who received information, most parents recognized specific SAI techniques and perceived benefits such as increased crop yield, reduced chemical use, and improved environmental outcomes. Logistic regression analysis in the full model shows that parent’s occupation (β = 6.584, P < 0.001), perceived benefits of SAI (β = 3.969, P < 0.001), and social influence from peers and community (β = 1.888, P < 0.05) were significant predictors of parent’s willingness to apply SAI practices at home.
Conclusions: These findings highlight the potential of school garden programs to promote SAI through the school context by training students, increasing their knowledge, and empowering them to act as a knowledge bridge to their families. This study also shows the importance of reinforcing the perceived benefits of SAI and leveraging social networks to enhance adoption at the household level.

From sun to shade: Cultivar-specific plasticity of robusta coffee in diverse light environments

Veera Klaipuk — 2026-04-20

Background and Objective: Coffee production faces increasing challenges from climate variability, particularly light availability, while the adaptability of robusta coffee to shaded environments remains insufficiently understood compared to arabica. This study evaluated phenotypic plasticity in five robusta coffee cultivars across contrasting light conditions using morpho-anatomical, physiological, and biochemical traits, with the Relative Distance Plasticity Index (RDPI) used to quantify trait responsiveness and identify adaptive strategies.
Methodology: One-year-old plants of five robusta coffee cultivars, namely Chumphon 2 (CH2), Chumphon 4 (CH4), R2017–1 (R–1), R2017–2 (R–2), and a local Thai variety (LO), were grown under three shading levels (0%, 50%, and 80%) in a factorial design (shade × cultivar) with five replicates, where individual plants served as experimental units. Morphological, anatomical, physiological, photochemical, and pigment traits were measured, and phenotypic plasticity was quantified using RDPI. Data were analyzed by two-way ANOVA followed by Duncan’s multiple range test (P < 0.05) in RStudio (v. 2022.02.3) using the “Agricolae” and “Plasticity” packages.
Main Results: Physiological/biochemical traits exhibited greater plasticity (RDPI = 0.16–0.25) than morpho-anatomical traits (0.10–0.13). Among cultivars, CH2 showed the highest plasticity (0.25), followed by LO (0.21), R–2 (0.20), and R–1 (0.19), whereas CH4 exhibited the lowest responsiveness (0.16). Shading significantly modified structural traits, increasing specific leaf area and reducing leaf thickness, palisade thickness, and stomatal density (P < 0.05). Physiological responses were significantly affected (P < 0.05), with increased photochemical efficiency (Fv/Fm) and chlorophyll content, alongside reductions in dark respiration (Rd) and light compensation point (LCP).
Conclusions: Phenotypic plasticity in robusta coffee was trait-specific and cultivar-dependent. Cultivars with higher RDPI values, particularly R–2 and CH2, exhibited broader responsiveness across light environments, whereas CH4 showed comparatively limited plasticity. These findings support the use of quantitative plasticity indices to guide cultivar selection in diversified coffee production systems.

The perceived efficiency and advantages of farm machinery: Evidence from paddy rice farmers in Nong Saeng district, Saraburi province, Thailand

Rungroge Kamondetdacha — 2026-04-20

Background and Objective: Farm mechanization plays a critical role in enhancing agricultural productivity. However, limited empirical evidence exists on how farmers’ operational experience influences their perceptions of machinery efficiency and advantages. This study aimed to evaluate farmers’ perceived efficiency and advantages of farm machinery and to examine the relationship between operational experience and these perceptions among paddy rice farmers in Nong Saeng district, Saraburi province, Thailand.
Methodology: A cross-sectional survey was conducted with 93 paddy rice farmers using a structured questionnaire. Perceived efficiency and advantages across six dimensions were assessed using a 5-point Likert scale. Data were analyzed using descriptive statistics and Spearman’s rank correlation coefficient to determine relationships between years of operational experience and perception variables.
Main Results: Farmers generally rated farm machinery efficiency as high, with tractors receiving the highest scores, while trucks showed comparatively lower evaluations. Tractors were the only machinery consistently rated “very good” across all advantage dimensions. “Increased working speed” was the most positively perceived benefit across all machinery types. Correlation analysis revealed a significant negative relationship between operational experience and perceived efficiency for tractors (r_s= -0.361, P < 0.05). Additionally, longer experience with tractors was negatively associated with perceived advantages in multiple dimensions, including labor reduction, productivity, output quality, and cost reduction. Similar negative correlations were observed in selected dimensions for other machinery types.
Conclusions: The findings indicate a perception gap between less experienced and more experienced users, with recent adopters exhibiting more favorable perceptions. This suggests the need for targeted extension strategies that consider farmers’ experience levels to enhance perception accuracy and support sustained adoption of mechanization.

Growth and yield performance of eggplant (Solanum melongena L.) under bat guano tea application in potted conditions

Derby E. Poliquit — 2026-04-20

Background and Objective: Eggplant (Solanum melongena L.) is an economically important vegetable crop in the Philippines, but productivity is often limited by declining soil fertility and reliance on synthetic fertilizers. Bat guano tea (BG tea), a nutrient-rich organic liquid fertilizer, has the potential to improve crop performance; however, its dose–response relationship under local conditions remains insufficiently quantified. This study aimed to evaluate the effects of different BG tea concentrations on growth, biomass allocation, and yield of eggplant under pot conditions.
Methodology: A randomized complete block design (RCBD) with six treatments (0, 10, 25, 55, 75, and 100 mL pot⁻¹) and three replications was conducted. BG tea was prepared from air-dried guano, diluted, and applied weekly for seven weeks after transplanting. Growth traits, root characteristics, phenology, and yield were measured. Data were analyzed using ANOVA, with mean separation by LSD (P < 0.05), and effect size quantified using eta squared (η²).
Main Results: BG tea application significantly affected vegetative growth and yield (P < 0.05). Higher concentrations (75–100 mL pot⁻¹) enhanced plant height, leaf production, root volume, and biomass accumulation. The highest yields were obtained at 75 mL pot⁻¹ (1.43 ± 0.09 t ha⁻¹; +27.68%) and 100 mL pot⁻¹ (1.37 ± 0.08 t ha⁻¹; +22.32%), although these were not statistically different from the control. Lower concentrations (10–55 mL pot⁻¹) resulted in reduced yield. A strong treatment effect was observed (η² = 0.97), indicating that BG tea concentration accounted for most yield variation. Excessive application (100 mL) promoted vegetative growth without proportional yield gain.
Conclusions: Moderate BG tea application (approximately 75 mL pot⁻¹) optimized growth-yield balance under pot conditions. While BG tea shows promise as an organic nutrient source, further field validation and comparison with conventional fertilization are required before broad recommendations.

Growth performance and survival of guppies (Poecilia reticulata) associated with dried Wolffia spp. supplementation in mixed-diet formulations

Thanchanok Moonthasri — 2026-04-20

Background and Objective: Feed costs represent a major constraint in aquaculture, making alternative protein sources such as Wolffia spp. of increasing interest. Although Wolffia spp. contains 20–48% protein, its practical inclusion for guppies remains unclear. This preliminary study examined growth and survival in guppies fed 0–60% dried Wolffia spp. (base feed weight basis) under a non-isoproteinous, mixed-diet formulation.
Methodology: A 6-week feeding trial was conducted with 135 female guppies (0.48 g initial mean weight) fed diets containing 0, 15, 30, 45, or 60% dried Wolffia spp. powder mixed with commercial feed. Growth, feed efficiency, condition factor, and survival were evaluated and analyzed using one-way ANOVA or Kruskal-Wallis test (P < 0.05).
Main Results: Dried Wolffia spp. contained 22.16% protein, 3.78% fat, 49.20% carbohydrate, and 319.46 kcal/100 g (AOAC analysis). Significant differences in growth performance were observed beginning at week 5 (P < 0.05). The highest growth trends were observed in the 45% inclusion group, with an average daily gain of 0.00429 g/day, specific growth rate of 0.74 ± 0.06%/day. Survival remained high across all treatments (88–100%). Median apparent feed conversion ratio remained comparable across treatments (P = 0.217), while apparent protein efficiency ratio (P = 0.006) and condition factor (P = 0.022) differed significantly among treatments. The 60% group demonstrated growth patterns comparable to the 45% group (P = 0.508) with a similar survival rate.
Conclusions: This study indicates that 45% dried Wolffia spp. inclusion (base feed weight basis; 31.03% of total diet) was associated with improved growth trends in guppies. However, as the design could not isolate the effect of Wolffia spp. per se from changes in overall diet composition, these exploratory results likely reflect increased dietary protein. Further isonitrogenous trials are required to support practical dietary recommendations.