Journal of Agricultural Science, Issue: Vol.18, No.6

Evaluation of Clethodim, Glufosinate, and Glyphosate Alone and in Tank-Mix with Residual Herbicides for Control of Johnsongrass (Sorghum halepense) Shoots and Rhizomes

Wed, 13 May 2026 01:32:12 +0000

Johnsongrass is one of the most difficult weeds to control due to its ability to regenerate from underground rhizomes. Johnsongrass has been a problematic weed for years in row crops in Mississippi. It can severely reduce yields in corn, cotton, soybean, and other row cropping systems. Two separate field studies were conducted in 2023 at the Delta Research and Extension Center in Stoneville, Mississippi to evaluate the effectiveness of clethodim, glufosinate, and glyphosate applied alone or tank-mixed with residual herbicides for johnsongrass rhizomes and seedlings control. No crops were included in this study, as it was carried out under non‑crop conditions. The experiment was conducted as a randomized complete block design with 12 herbicide treatments and three replications in a natural johnsongrass population (rhizomes and seedlings). Herbicide treatments included clethodim, glyphosate, and glufosinate applied alone or tank‑mixed with the residual herbicides brake, boundary, or acuron for control of johnsongrass rhizomes and seedlings. Johnsongrass shoot control from the application of clethodim alone was 83% four-weeks after application. Antagonism occurred when boundary or acuron were mixed with clethodim which reduced aboveground biomass control. Both glyphosate and glufosinate, whether applied alone or with residual herbicides, maintained excellent shoot control (>96%) with no evidence of antagonism. Four weeks after application, the entire test area was mowed down (after final johnsongrass evaluation) for possible johnsongrass regrowth. Johnsongrass regrowth was observed following all treatments except the glyphosate application. The residual herbicides brake, boundary, and acuron did not improve clethodim or glufosinate performance in preventing johnsongrass regrowth from rhizomes. Glyphosate alone or tank-mixed with residual herbicides were the only treatments that provided 100% of johnsongrass control with no-regrowth.

Epidemiological Dynamics of Alternaria Diseases in Potato (Solanum tuberosum L.): Climate-Disease Interactions, Inoculation Timing and Economic Impacts in Eritrea

Wed, 13 May 2026 01:35:53 +0000

Alternaria diseases, caused by Alternaria solani (Early Blight) and A. alternata (Brown Spot), threaten potato production globally. This study quantified the epidemiological patterns of the diseases, climate-disease interactions, transmission dynamics, and economic impacts across three climatically different zones of Eritrea (Adi Keih, Asmara, and Halhale) during the 2025 growing season. A randomized complete block design with four treatments of different pathogen inoculation times, with three replications, was used. Disease assessments were conducted at five crop development stages. Apparent infection rate, area under disease progress curve (AUDPC), ANOVA, Pearson correlation, and linear regression were used for statistical analysis. Asmara exhibited high disease risk with Early Blight severity of 4.19 and Brown Spot severity of 3.13, with 100% incidence and the highest transmission rates (0.122/day for Early Blight, 0.108/day for Brown Spot). Moderate humidity (54.1%) combined with warmer temperature (19.2 °C) was found to be conducive. Across all places, the disease progressed rapidly between 30 and 45 days after planting. Negative correlations between transmission efficiency and yield were observed for both diseases. Yield losses reached 42% (13 t/ha) in high transmission environments, which is approximately Eritrean Nakfa (ERN) 130,000/ha (USD 8,667/ha) in economic losses. Inoculation timing did not affect AUDPC values, indicating that environmental factors outweigh pathogen incidence timing. Our findings indicate that moderate humidity (54-58%) coupled with warmer temperatures (19-20 °C) create ideal conditions for disease transmission, adding a scientific basis for understanding Alternaria epidemiology. The critical crop age period of 30-45 days after planting represents the highest vulnerability window requiring intensive monitoring. These findings, while based on a single growing season, provide a foundation for multi-year validation across broader geographic scales. Our study supports the development of site-specific, climate-informed, and economically optimized integrated disease management strategies that can help farmers achieve sustainable potato production in the face of changing climate conditions.

Assessment of the Severity and the Incidence of African Cassava Mosaic Disease in Western Democratic Republic of Congo

Wed, 13 May 2026 01:56:54 +0000

This study focuses on the assessment of the severity and incidence of African Cassava Mosaic Disease (CMD) in the western Democratic Republic of the Congo (DRC) to assess the status of CMD and determine viral strains responsible for the disease. Epidemiological surveys were conducted in western DRC (former provincial configuration) from 2016 to 2017 following the standard protocol adopted Central and West African Virus Epidemiology (WAVE) programme. A total of 292 cassava leaf samples, exhibiting CMD symptoms and asymptomatic characteristics, were collected from 146 fields distributed across five provinces (Equateur, Kasaï-Oriental, Kinshasa, Bas-Congo and Bandundu). The mean rate incidence and mean severity in the field were 31.4% and 3, respectively; indicating that the Province was highly infected with CMD. In all provinces, infections transmitted by cuttings were more frequent.common. Molecular PCR analyses revealed an overall infection rate of 89.73%, with the detection of ACMV, EACMV, as well as other unidentified Begomoviruses. Mixed infections (ACMV+EACMV) and virus detected and not identified, were also observed. Results indicate a significant predominance of ACMV with a variable distribution across different areas. The detection of unidentified viruses in several samples suggests the presence of variants that are still poorly characterised; requiring further sequencing studies. These results highlight the importance of large scale distribution and promotion programs for CMD resistant plant materiel in these provinces.

Postharvest Preservation and Marketing Practices of Potato (Solanum tuberosum) in the Bagga Valley in the Tahoua Region, Niger

Wed, 13 May 2026 01:44:11 +0000

This study examines postharvest preservation and marketing practices of potato (Solanum tuberosum) producers in the Bagga Valley, Tahoua region of Niger. Based on survey data collected from approximately 200 farmers across selected municipalities, the study combines descriptive statistics with a binary logistic regression model to identify the determinants of storage adoption and examine prevailing market practices. Results reveal that only a limited proportion of producers practice storage, mainly due to inadequate storage infrastructure and limited access to improved storage technologies, resulting in a relatively short storage duration averaging about 30 days. The econometric analysis shows that cultivated area, farming experience, access to agricultural inputs, and membership in producers’ organizations significantly increase the likelihood of storage adoption. Despite a high level of cooperative membership, marketing channels remain dominated by intermediaries, limiting farmers’ bargaining power and income opportunities. These constraints contribute to market saturation at harvest and price volatility. The findings suggest that investments in decentralized storage facilities, farmer training, and rural infrastructure are essential to improve potato value chain efficiency, enhance producers’ incomes, and support sustainable agricultural development in the Sahelian context.

Genetic and Phenotypic Diversity of Cassava Cultivars in Southwestern Democratic Republic of Congo

Wed, 13 May 2026 01:54:11 +0000

Cassava (Manihot esculenta Crantz) is a key staple in the Democratic Republic of Congo (DRC), yet the diversity of farmer-maintained cultivars remains insufficiently documented, particularly in the southwest. This study assessed the morphological diversity and population structure of cassava cultivars collected from farmers’ fields in this region. A survey was conducted in 112 fields across Kinshasa, Kongo Central, and Mai-Ndombe, where 220 cultivars were recorded. Characterization relied on nine qualitative descriptors from standard cassava lists, complemented by altitude and whitefly abundance. Multiple Correspondence Analysis (MCA) was used to explore phenotypic variability, followed by Hierarchical Ascending Classification (HAC) to group cultivars based on similarity. Discriminant Factor Analysis (DFA) evaluated the robustness of the classification. The first five MCA dimensions explained 42.9% of total variation. Leaf pigmentation, petiole colour, plant age, and cassava mosaic disease severity were the main discriminating traits. HAC identified seven phenotypic groups of unequal size, indicating substantial diversity within the population. DFA showed high classification accuracy (94.1%), confirmed by Leave-One-Out cross-validation (92.3%). Overall, the results reveal significant phenotypic variability in cassava cultivated in southwestern DRC and emphasize its importance for breeding programs aimed at enhancing disease resistance, productivity, and adaptation to local environmental conditions. These findings provide a valuable baseline for conservation and genetic improvement efforts and highlight the need for integrating farmer knowledge with formal breeding strategies. Future research should incorporate molecular markers to better resolve genetic relationships and support the development of resilient, high-yielding cultivars adapted to diverse agroecological conditions in practice.

Reviewer Acknowledgements for Journal of Agricultural Science, Vol. 18, No. 6

Wed, 13 May 2026 01:58:30 +0000

Reviewer acknowledgements for Journal of Agricultural Science, Vol. 18, No. 6, 2026.