Thai Journal of Agricultural Science

Determinants of tractors adoption among smallholder farmers in Makuey district, Gambella region, Ethiopia

Chuol Bor, Duol Khon — Sun, 28 Dec 2025 00:00:00 +0700

Background and Objective: The Gambella region has significant agricultural potential. However, various obstacles have prevented the development of agriculture and limited smallholder farmers’ capabilities to increase their income. This study aimed to determine the adoption of tractors by smallholder farmers in the Makuey district.
Methodology: The study sample comprised 250 smallholder farmers from the Makuey district. A multi-stage sampling technique was used, beginning with purposive sampling to choose the district because of its low tractor adoption by smallholder farmers. Simple random sampling was used to select kebelles, followed by random sampling of farmers within each village. Data were gathered through focus group discussions, structured interviews, questionnaires, and key informant interviews. The study employed mean, standard deviation, frequency, percentage, chi-square tests, t-tests, and binary logistic regression to analyze the data.
Main Results: The findings revealed that access to credit was positively associated with farmers’ tractor adoption (χ² = 10.000, P < 0.01). The total annual income showed a statistically significant mean difference (t = -3.470, P < 0.01) and farming experience (t = 2.015, P < 0.05) between adopters and non-adopters. Furthermore, binary logistic regression revealed that educational level (P < 0.05), cultural norms (P < 0.01), total annual income (P < 0.01), and access to subsidies (P < 0.01) were the main variables that influenced farmers’ tractor adoption.
Conclusions: Increasing tractor adoption among smallholder farmers is imperative and will require policy intervention. Increasing access to credit on favorable terms, strengthening farmer training programs, and improving income diversification can each contribute to alleviating financing and knowledge constraints. Reducing cultural norms through sensitization and raising subsidies or cheap loan rates for machinery would also facilitate adoption. Harmonizing these interventions can transform agriculture and enhance farm income in the region.

Cluster analysis of organic rice production systems and management patterns: Case study of Sathing Phra Peninsula, Southern Thailand

Priyakorn Bunsong, Sarunyoo Kanchanasuwan, Pilaiwan Prapruit — Sun, 28 Dec 2025 00:00:00 +0700

Background and Objective: The transformation of traditional rice farming into sustainable organic systems presents significant challenges, particularly in regions with unique geographical contexts. In Southern Thailand’s Sathing Phra Peninsula, organic rice production covers only 0.31% of the total cultivation area, yet exhibits distinctive adaptation patterns. This study aimed to analyze the heterogeneity of organic rice production systems in the peninsula through cluster analysis, focusing on identifying and characterizing different farmer typologies based on their production practices, resource management, and certification patterns.
Methodology: The study examined 47 certified organic rice farmers across four districts during the 2022/23 growing season. Data collection included semi-structured interviews, field observations, and focus group discussions. Eight standardized variables were analyzed using hierarchical clustering methods: certification patterns, cultivation frequency, farming methods, water source utilization, yield levels, farmland area, seed management, and labor utilization. Statistical analysis employed Ward’s method with Euclidean distance, followed by one-way ANOVA.
Main Results: Three distinct farmer groups were identified: 1) commercial organic farmers (21.28%), characterized by larger cultivation areas (>11.98 rai) and higher yields (>500 kg/rai), 2) integrated organic farmers (27.66%), combining traditional methods with modern technology, and 3) traditional organic farmers (51.15%), primarily smallholders following conventional practices. Statistical analysis revealed significant differences (P < 0.05) across all variables, with yield variations showing the highest variance (F = 68.44). Price premiums varied by 15–20% between groups, reflecting market access disparities.
Conclusions: Three distinct farmer clusters were identified with significant productivity variations (P < 0.05). Commercial organic farmers achieved the highest yields (>500 kg/rai) on larger farms, while traditional smallholders (51.15%) maintained lower productivity (300–400 kg/rai). Infrastructure access and water management proved critical determinants of organic rice farming success, requiring differentiated support strategies for sustainable development.

Cloning and characterization of a candidate bacterial leaf blight resistance gene, a serine/threonine protein kinase, in rice

Sun, 28 Dec 2025 00:00:00 +0700

Background and Objective: Bacterial leaf blight (BLB), caused by Xanthomonas oryzae pv. oryzae (Xoo), is a major constraint on rice (Oryza sativa L.) production, particularly in Asia, where rice is a dietary staple. Enhancing host resistance through the deployment of resistance genes remains one of the most effective strategies in rice breeding programs. Advances in molecular tools, including marker-assisted selection (MAS), quantitative trait loci (QTL) mapping, and genome-wide association studies (GWAS), have facilitated the identification of at least 46 BLB resistance genes, 11 of which have been functionally characterized. Building on the previous work, 127 putative BLB resistance genes were identified via GWAS. This study aimed to examine the expression and variation of candidate genes to identify genes potentially contributing to BLB resistance.
Methodology: Quantitative PCR (qPCR) was used to evaluate the expression of selected candidate genes in two rice cultivars: IR57514 (a resistant cultivar) and Jao Hom Nin (a susceptible cultivar), following Xoo inoculation. One gene, LOC_Os01g66860, encoding a serine/threonine protein kinase, was selected for further analysis. A phylogenetic analysis was performed to assess evolutionary conservation across the plant kingdom, and the gene was cloned and sequenced from both cultivars.
Main Results: LOC_Os01g66860 was significantly upregulated in the resistant cultivar after pathogen challenge. Phylogenetic analysis confirmed its conservation across plant species. Cloning and sequencing revealed one amino acid substitution between the resistant and susceptible cultivars.
Conclusions: These findings suggest that LOC_Os01g66860 may play a crucial role in BLB resistance. The results provide a foundation for future functional validation and highlight its potential application in rice breeding programs aimed at improving disease resistance. However, a limitation of this study is the need for further functional tests, such as gene knockout or overexpression experiments, to confirm the gene’s specific role in resistance.

Effect of acid-hydrolyzed soybean waste as a biostimulant on cos lettuce growing using two types of hydroponic systems

Sun, 28 Dec 2025 00:00:00 +0700

Background and Objective: Plant biostimulants produced from agricultural waste have been reported to promote plant growth, stimulate phytochemical content, and promote the valorization of agricultural by-products. This study investigated the impact of soybean-derived protein hydrolysate (SPH) on lettuce production in hydroponic systems using a reduced chemical fertilizer solution concentration (FSC).
Methodology: Cos lettuce (Lactuca sativa L.) was cultivated using both deep-water culture (DWC) and nutrient film technique (NFT) hydroponic systems. The test used a factorial design arranged in a randomized complete block design (RCBD) with two factors: SPH concentration (0 mL/L [SPH0] and 1.0 mL/L [SPH1]) and FSC (half- and full-strength Hoagland nutrient solutions). Each treatment combination was replicated twice with 30 plants per unit, where growth, biomass, and phytochemical parameters were analyzed using two-way ANOVA and Duncan’s multiple range test.
Main Results: SPH1 significantly enhanced plant growth and phytochemical content in both hydroponic systems (P < 0.05). In half-strength nutrient solutions with SPH1, lettuce head diameter and biomass increased by 1.16- and 1.17-fold in deep-water culture, and by 1.16 and 1.61-fold in nutrient film technique, respectively, with greener and more intense color than the control. Additionally, the total phenolic contents, total flavonoid contents, DPPH• scavenging activity, ascorbic acid content, soluble protein content, and nitrate content increased by 1.47, 1.47, 1.11, 1.02, 1.33, and 1.23-fold, respectively, in the DWC system, and by 1.40, 2.40, 2.98, 1.15, 1.69, and 1.71-fold, respectively, in the NFT system.
Conclusions: The findings of this study indicated that adding SPH1 in both systems enhanced lettuce growth, yield, and quality and proved to be an effective method for improving nutritional contents and antioxidant activities while enabling reduced chemical fertilizer use. Although nitrate content increased, levels remained within acceptable daily intakes.

Effect of adoption of Sustainable Agricultural Practices (SAP) on profit efficiency among cassava farmers in Ogun State, Nigeria

Sun, 28 Dec 2025 00:00:00 +0700

Background and Objective: Despite cassava’s many benefits to the world, many farmers still embrace unsustainable farming methods, which frequently lead to pest infestations, degraded soil, and low profits. Adopting Sustainable Agricultural Practices (SAP), such as integrated pest management, organic manuring, and agroforestry systems, could undoubtedly improve the profitability of cassava production. Nevertheless, there is still a shortage of empirical evidence regarding the economic impacts of these practices, particularly concerning profit efficiency. The study was conducted in Ogun State, Nigeria, to assess the adoption of SAP and its impact on profit efficiency among cassava farmers. The study described the farmers’ socio-economic characteristics, identified the adopted SAP, determined the profitability of cassava production, and examined the determinants of profit efficiency.
Methodology: The study’s data set was primary. It was obtained from 120 farmers using a questionnaire. The farmers were selected via a multi-stage sampling procedure. Data analysis methods include descriptive statistics, budgetary analysis, and the Cobb-Douglas stochastic frontier profit function.
Main Results: The results revealed that the cassava farmers were predominantly male (79.20%), with an average farmer being 45 years old. SAP adopted includes soil enrichment (65.00%), integrated pest management (63.30%), intercropping (59.30%), crop rotation (55.80%), and mixed farming (54.20%), among others. Furthermore, given the profitability indices, cassava production is profitable in the study area. Determinants of profit efficiency include farm size, labour cost, cost of cassava stem, age, education, extension contact, mixed farming, and integrated pest management.
Conclusions: The study’s findings suggest that cassava farming is profitable and SAP, like mixed farming and integrated pest management, influences profit efficiency. Farmers also need increased extension services to increase their knowledge and awareness of SAP.

Cross- and multiple-herbicide resistance of penoxsulam- resistant barnyardgrass in Central Thailand paddy fields

Mongkol Sripeangchan, Tosapon Pornprom — Sun, 28 Dec 2025 00:00:00 +0700

Background and Objective: Echinochloa crus-galli (L.) P. Beauv. is the most troublesome weed in paddy fields. Farmers in Central Thailand have observed poor control with the labeled rate of penoxsulam, an acetolactate synthase (ALS) inhibitor. This study was conducted to confirm and quantify barnyardgrass resistance to penoxsulam in the region and to evaluate cross- and multiple-resistance patterns against commonly used herbicides in paddy fields.
Methodology: A split-plot design with four replications was used. The main plot consisted of six penoxsulam dose rates (0, 7.03, 14.06, 28.12, 56.24, and 112.48 g a.i./ha), and the sub-plot included resistant (R) and susceptible (S) biotypes. Both biotypes were assessed for I₅₀ (visual injury) and GR₅₀ (plant height and fresh weight). Cross-resistance to ALS inhibitors from three chemical families and multiple-resistance to other herbicide mechanisms of action were also evaluated.
Main Results: The R-biotype showed 53.78–64.52-fold higher resistance to penoxsulam than the S-biotype. Cross-resistance was detected to bispyribac-sodium, pyribenzoxim, and triafamone, while multiple-resistance occurred to metamifop (acetyl-CoA carboxylase (ACCase) inhibitors) and quinclorac (synthetic auxin). No resistance was detected to profoxydim, propanil, or florpyrauxifen-benzyl.
Conclusions: This study provides the first confirmed and quantified case of penoxsulam-resistant barnyardgrass in Central Thailand paddy fields, revealing high-level resistance and a clear profile of cross- and multiple-herbicide resistance. These findings emphasize the need for integrated weed management strategies, including herbicide rotation across different modes of action and the incorporation of non-chemical control measures, to slow the spread and minimize the impact of ALS-resistant E. crus-galli populations in paddy fields.