Journal of Agricultural Science, Issue: Vol.18, No.4

Investigation of Palmer Amaranth (Amaranthus palmeri) Resistance to Glufosinate in Mississippi

Mon, 09 Mar 2026 13:02:36 +0000

One of the most critical issues for weed scientists today is the management of herbicide-resistant weeds. Herbicide-resistant Palmer amaranth [Amaranthus palmeri (S.) Watson] is the most problematic pest problem for corn (Zea mays L.), cotton (Gossypium hirsutum L.), and soybean (Glycine max (L.) Merr.) producers in Mississippi. Greenhouse research was conducted at the Delta Research and Extension Center from 2019 to 2021 to investigate Palmer amaranth accessions potentially resistant to glufosinate and its distribution in Mississippi. In the 2019 screening, 20 out of 54 Palmer amaranth populations tested had individuals exhibiting 2 to 20% survival from a 1X rate (0.68 kg ai ha^-1 as recommended rate) of glufosinate. Bolivar-3 (9% survival), Coahoma-1 (11% survival), Holmes-3 (11% survival), Issaquena-2 (13% survival), Tunica-4 (17% survival), and Yazoo-3 (20% survival) accessions had the highest rate of survival. Twelve of those accessions were selected for a dose-response study in August 2020. Palmer amaranth plants that survived a 1X rate of glufosinate (suspected glufosinate-resistant Palmer amaranth) in 2019 were transplanted to larger pots and grown for seed production in 2020. In 2020, seedheads from female Palmer amaranth were harvested, threshed, and cleaned to obtain progeny, which were then stored until further evaluation. Only one Palmer amaranth plant (F1 progeny) from Quitman-1, Tunica-4, and Washington-5 survived glufosinate (1X) in 2020. No Palmer amaranth plants survived 2X and 4X rates of glufosinate in 2020. In the 2021 screening, four out of five original Palmer amaranth accessions selected (seed from 2017) survived, except for Issaquena-2 accession. Palmer amaranth individuals from accession Coahoma-1, Holmes-3, Tunica-4, and Yazoo-3 exhibited 3.7, 3.2, 1, and 1% survival, respectively, from a 1X rate of glufosinate. No F1 Palmer amaranth survivors were identified from any of those accessions evaluated. At this time, we cannot say with certainty that these survivors are resistant to glufosinate. Additional research (including physiological and molecular studies) needs to be conducted to confirm whether offspring of these survivors have developed resistance to glufosinate.

Competitive Performance of Chenopodium quinoa Genotypes in Competition With Weed Species

Mon, 09 Mar 2026 13:08:37 +0000

The study of competitive ability between crops and weeds is relevant for the adoption of more sustainable control methods, with lower costs for producers and less environmental impact. In this context, the objective of this work was to evaluate the competitive ability of quinoa genotypes (Q 1303, Q 1324, and Q 1331) in association with the weeds Euphorbia heterophylla and Urochloa plantaginea in different plant proportions within the association. The experiment was conducted in a randomized block design with four repetitions. The treatments were distributed in proportions (100:0, 75:25, 50:50, 25:75, and 0:100%) of crop and/or weed plants corresponding to 20:0, 15:5, 10:10, 5:15, and 0:20 plants per pot. The competitiveness of the species was analyzed through diagrams applied to substitution experiments and through relative competitiveness indices. Fifty days after species emergence, measurements were made on tillering of U. plantaginea, number of leaves of quinoa and/or Euphorbia, plant height, stem diameter, chlorophyll index, gas exchange, leaf area, dry mass of the aerial part, as well as the measurement of nitrogen and phosphorus concentrations in the crop leaves. Heavy interspecific competition occurred between quinoa genotypes the weeds, with mutual harm to the species involved in the community. U. plantaginea proved to be more aggressive to quinoa compared to E. heterophylla. The quinoa genotypes showed similar competitive abilities, with emphasis on Q1303, which showed greater tolerance to association with U. plantaginea. The most detrimental competition for quinoa was interspecific, indicating the need for control of E. heterophylla and U. plantaginea even at low infestation levels.

Marketing Determinants Influencing Adoption of Agricultural Machinery Among Smallholder Maize Farmers in Kenya

Mon, 09 Mar 2026 13:11:37 +0000

It is widely recognized that agricultural mechanization can significantly transform the productivity of smallholder farming systems in sub-Saharan Africa. However, the level of adoption remains very low despite various policy initiatives and donor-funded programs. This study examined the marketing determinants influencing the adoption of agricultural machinery by smallholder maize farmers participating in the Machinery Ring Project in Bungoma County, Kenya. The research used a cross-sectional design employing both quantitative and qualitative methods to explore social and economic attributes, market conditions, and farmers’ adoption behavior. A total of 1,000 farmers were surveyed, and 150 respondents were selected through a stratified random sampling method proportionate to the size of the population. Primary data were collected using semi-structured questionnaires. Data analysis involved descriptive and inferential statistics conducted with SPSS (v.23). The study employed multiple linear regression to assess how product information, product price, event marketing, and face-to-face marketing influenced machinery adoption. The results indicated that face-to-face marketing (β = 0.456, p < 0.001), product information (β = 0.216, p = 0.018), and event marketing (β = 0.174, p = 0.038) are significant drivers of adoption. Conversely, product price (β = 0.026, p = 0.745) was not statistically significant. The findings suggest that cost is not the primary factor in the decision to mechanize. The study concludes that enhancing farmer-centered marketing communication, digital extension services, and a cooperative-based service model will be effective in accelerating inclusive mechanization and sustainable transformation in Kenya.

Validation of the QUEFTS Model for Predicting Fertilizer Requirements in Maize and Common Beans

Mon, 09 Mar 2026 13:15:26 +0000

Inherently low soil fertility continues to constrain crop productivity among smallholder farmers in Zambia. To remedy this, fertilizer application is often guided by blanket recommendations that fail to account for differences in soil nutrient supply and crop demand. The Quantitative Evaluation of the Fertility of Tropical Soils (QUEFTS) model can estimate balanced nitrogen, phosphorus, and potassium requirements, but its performance when calibrated using rapid soil testing kit data remains limited. This study validated QUEFTS-based recommendations for maize and common beans using soil data obtained from a rapid soil testing kit. On-farm trials were conducted at 12 farmer-managed sites and one researcher-managed site during the 2024/2025 season. Fertilizer treatments included QUEFTS-generated rates, a blanket rate (current practice), and control (no fertilizer) treatments. Significant treatment effects were observed for maize grain yields and biomass (p < 0.001) with the QUEFTS treatment producing the highest mean grain yield (5.6 t ha^-1), followed by the blanket rate (4.8 t ha^-1) and the control (3.2 t ha^-1). For common beans, grain yield under QUEFTS was significantly higher than the control but not different from the blanket treatment, while aboveground biomass did not vary among treatments. Model evaluation indicated moderate predictive performance for maize (RMSE = 1.91 and d = 0.41) but overestimated the bean yield. These findings indicate that integrating rapid soil testing with the QUEFTS model can improve site-specific fertilizer management in maize although further refinement is required for common beans under variable field conditions.

Agricultural Behaviors of Maize Producers in Response to Climate Variability in the District of Banyo (Adamawa Region, Cameroon)

Mon, 09 Mar 2026 13:18:20 +0000

Maize production, a strategic food crop for food security and rural incomes in Cameroon, is increasingly threatened by climate change. The main objective is to assess the extent to which farmers’ adaptive behaviors contribute to strengthening the resilience of family farms in the Banyo subdivision of the Adamawa region. The methodological approach combined a literature review with a field survey conducted among 234 maize producers. Data analysis revealed that more than 80% of farmers adjust their cropping calendar, delaying or advancing sowing dates to cope with prolonged droughts at the beginning of the agricultural season. Around 97% adopt improved seeds and implement practices such as field irrigation, crop diversification, intercropping, agricultural intensification, and the use of organic fertilizers to compensate for declining soil fertility and to optimize yields. The adoption of off-season cropping further illustrates a willingness to innovate and secure production despite climatic uncertainties. These agricultural practices highlight both a strong capacity for local adaptation and the persistence of significant vulnerabilities. While farmers are mobilizing a diverse repertoire of climate-smart practices, their effectiveness remains constrained by technical, economic, and institutional barriers. The study underscores the urgent need for strengthened agricultural extension services, improved access to timely climate information, and wider dissemination of appropriate technologies tailored to local contexts. Beyond its empirical findings, this research contributes to enriching scientific debates on agricultural adaptation in Central Africa. It also provides concrete insights for guiding public policies towards sustainable resilience strategies that build on farmer behavior, local innovations, and knowledge systems.

Drivers of Farmers Satisfaction and Loyalty at Agricultural Exhibitions in Uganda: An Integrated Theoretical Approach

Mon, 09 Mar 2026 13:23:07 +0000

Agricultural exhibitions increasingly serve as platforms for disseminating innovations and bridging the farmer-researcher gap. However, limited empirical evidence exists on how such exhibitions shape farmers’ satisfaction and their subsequent loyalty to exhibiting research institutions. This study examines the psychosocial and organizational determinants of farmers’ satisfaction with the National Agricultural Research Organisation (NARO) following technological exposure at the Jinja Agricultural Show in Uganda, and assesses whether such satisfaction translates into institutional loyalty. Survey data from 300 event attendees (farmers) were analyzed using structural equation modeling (SEM). Results indicate that intrinsic motivation (β = 0.228, p < .001), self-efficacy (β = 0.369, p < .001), and peer approval (β = 0.330, p < .001) significantly enhance satisfaction, whereas perceived behavioral control has a significant negative effect (β = -0.326, p < .001). Satisfaction negatively predicts loyalty (β = -0.118, p = .041), suggesting that although farmers value NARO demonstrations, they may prefer to obtain technologies from commercial vendors rather than maintain loyalty to the research institution. Extrinsic motivation and push-pull motives did not significantly predict satisfaction. These findings refine Self-Determination Theory, the Theory of Planned Behavior, and Organizational Support Theory by demonstrating that satisfaction in agricultural exhibitions is primarily driven by internal and social factors, whereas loyalty is shaped by broader institutional visibility and post-event reinforcement. Practically, the study highlights the need for co-branding with technology vendors, stronger post-event support pathways, and peer-driven engagement mechanisms to enhance farmer loyalty to research institutions.

Reviewer Acknowledgements for Journal of Agricultural Science, Vol. 18, No. 4

Mon, 09 Mar 2026 13:25:11 +0000

Reviewer acknowledgements for Journal of Agricultural Science, Vol. 18, No. 4, 2026.