Journal of Agricultural Science, Issue: Vol.18, No.7

Efficacy of Diflufenican Plus Metribuzin Applied Preemergence in Soybean

Wed, 10 Jun 2026 00:54:16 +0000

Diflufenican is a selective phenyl ether herbicide belonging to WSSA Group 12 Limited information is available regarding its efficacy, crop safety, and interaction with metribuzin when applied preemergence (PRE) in soybean under Ontario growing conditions. Field experiments were conducted in 2018 and 2019 across three environments in southwestern Ontario, Canada, to evaluate soybean tolerance and weed control with preemergence (PRE) applications of diflufenican, metribuzin, and their combinations. Treatments included metribuzin (150, 200, and 300 g ai ha^-1), diflufenican (60, 75, 90, 105, 120, 150, and 180 g ai ha^-1), and diflufenican plus metribuzin (1:2 ratio) mixtures (225, 300, and 450 g ai ha^-1) applied PRE. Soybean injury was ≤ 8% at 1 and 2 weeks after emergence (WAE) for all treatments. Soybean injury was not observed beyond 2 WAE. Metribuzin applied PRE controlled Powell amaranth (13-97%), redroot pigweed (30-38%), common ragweed (0-38%), common lambsquarters (11-35%), flower-of-an-hour (0-33%), ladysthumb (0-87%), common purslane (5-87%), and wild mustard (25-33%) at 8 WAA and controlled barnyardgrass (14-66%) and green foxtail (14-65%) at 2 WAA. Diflufenican applied PRE controlled Powell amaranth (52-100%), redroot pigweed (35-100%) common ragweed (0-11%), common lambsquarters (0-13%), flower-of-an-hour (0-85%), ladysthumb (≤0-13%), common purslane (10-87%), and wild mustard (47-99%) at 8 WAA and barnyardgrass (0-20%) and green foxtail (0-20%) at 2 WAA. Diflufenican plus metribuzin mixtures applied PRE provided broader and more consistent control, including Powell amaranth (72-89%), redroot pigweed (71-100%), common ragweed (8-43%), common lambsquarters (26-54%), flower-of-an-hour (31-97%), ladysthumb (16-76%), common purslane (46-94%), and wild mustard (56-99%) at 8 WAA and barnyardgrass (10-69%) and green foxtail (11-68%) at 2 WAA. Observed responses were generally additive, with minor antagonistic or synergistic interactions for specific species at specific rating timings. Results indicate that diflufenican has activity on Powell amaranth, redroot pigweed and wild mustard. Diflufenican combined with metribuzin improved the spectrum and level of weeds controlled. Diflufenican co-applied with metribuzin is a safe and effective PRE option for control of some weed species in soybean.

Thermal Performance and Morphological Variation of Diceraeus melacanthus (Hemiptera: Pentatomidae) Under Controlled Rearing

Wed, 10 Jun 2026 01:00:23 +0000

The neotropical green-belly stink bug, Diceraeus melacanthus (Dallas, 1851), is considered a major pest of maize and wheat production systems in South America, particularly under no-tillage systems and soybean–maize crop succession. Given the influence of climate change on arthropod development, this study aimed to characterize the effect of five constant temperatures (16, 21, 26, 31, and 36 °C) on the morphometrics and weight variations of D. melacanthus across all developmental phases. The experiment was conducted under controlled laboratory conditions ((14:10 h L:D photoperiod; 65±15% relative humidity) using a completely randomized design. Morphometric parameters, including total body length, pronotum width, abdomen width, rostrum length, and humeral angle length, were measured alongside fresh weight (mg). Results indicated that the thermal range of 26-31 °C represents the physiological optimum, promoting maximum growth and biomass accumulation, with adults reaching a significantly higher mean weight (67.9 mg) at 31 °C. Conversely, temperatures of 21 °C and 36 °C acted as limiting factors, significantly reducing abdominal width and humeral angle development, particularly in the fourth and fifth instars. Individuals reared under laboratory conditions exhibited larger morphometric values than those previously reported for field populations, likely due to the high-quality, diversified diet provided. The high phenotypic plasticity exhibited across the 16-36 °C gradient underscores the resilience of D. melacanthus to climatic fluctuations, enabling its year-round persistence in agricultural fields. These findings provide essential biological parameters for improving population growth models and strengthening Integrated Pest Management (IPM) strategies under future climate scenarios.

Factors Influencing the Adoption of Mechanization among Smallholder Rice Producers in Mwea Irrigation Scheme, Kenya

Wed, 10 Jun 2026 01:03:10 +0000

Agricultural mechanization is widely regarded as a critical pathway for improving smallholder productivity, reducing labour bottlenecks, and enhancing the efficiency of agri-food systems in the Global South. Recent reviews show that mechanization can support sustainable transformation, but its uptake remains highly uneven because adoption is shaped by farm size, purchasing power, service markets, and institutional access rather than machinery availability alone. In Kenya, rice is a strategic food and commercial crop, yet mechanization among smallholder rice farmers remains partial across key operations such as land preparation, irrigation, and harvesting. This study examined factors influencing the adoption of mechanization among smallholder rice producers in Mwea Irrigation Scheme, Kenya. Using cross-sectional survey data from 384 households, the study employed descriptive statistics and a multivariate probit model to analyze three interrelated adoption decisions: tractor use, mechanized irrigation, and mechanized harvesting. Results showed that mechanization choices were positively correlated, confirming complementarity across technologies. Gender significantly influenced tractor use and mechanized harvesting, while education positively affected tractor uses and mechanized irrigation. Household income and access to credit increased the likelihood of adopting tractor use and mechanized irrigation. Group membership was important for mechanized irrigation, whereas rice farming experience and land size significantly influenced mechanized harvesting. The findings indicate that mechanization adoption in smallholder rice systems is simultaneously shaped by socio-economic characteristics, institutional support, and farm structure. The study concludes that inclusive mechanization policy in Kenya should strengthen extension, credit access, service markets, farmer organizations, and gender-responsive support if mechanization is to contribute meaningfully to rice sector transformation. Empirical data and model results are drawn from the attached study results.

In vitro Regeneration of Two Local Bambara Groundnut Landraces [Vigna subterranea (L.) Verdc.] in Kenya

Wed, 10 Jun 2026 01:05:17 +0000

Bambara groundnut [Vigna subterranea (L.) Verdc.] is a climate-resilient and nutrient-dense legume with limited genetic improvement in Kenya due to the absence of efficient in vitro regeneration systems. This study evaluated regeneration responses of two Kenyan landraces, Cream with Black Eye and Yellow with White Eye, using different explant sources and plant growth regulator regimes. Callus induction was achieved in all explants, with frequencies reaching 100% under 2,4-dichlorophenoxyacetic acid and 50-100% under naphthaleneacetic acid. Direct shoot regeneration from embryo axes cultured on Murashige and Skoog medium supplemented with 0.25 mg/L 6-benzylaminopurine produced the highest proliferation, yielding mean shoot numbers of 34.8 and 37.2 per explant in the two landraces. No shoot regeneration was observed from callus under any treatment. Rooting frequency reached 80-93% at 0.2 mg/L indole-3-butyric acid. Direct organogenesis proved more reliable than callus-mediated regeneration. These findings establish a reproducible regeneration protocol for Kenyan Bambara groundnut and provide a basis for propagation and future biotechnological applications.

Irrigated Sorghum as a Strategy for Farmers’ Climate Resilience in Chad

Wed, 10 Jun 2026 01:10:17 +0000

Sorghum is a cereal crop traditionally grown under rainfed conditions in sub-Saharan Africa. In the context of climate change, its production is increasingly jeopardized. Growing this crop during the dry season under irrigation is being explored as an innovative approach to enhance farmers’ climate resilience. A field experiment conducted at a Technology and Innovation Park (TIP) established at the headquarters of the Institut Tchadien de Recherche Agronomique pour le Développement (ITRAD), located between 14°57.6ʹ and 15°2.4ʹ North latitude and 12°4.8ʹ and 12°9.6ʹ East longitude, using the rainfed sorghum variety S35, provided key insights into this concern. A preliminary soil fertility assessment was carried out, and integrated soil fertility management (ISFM) techniques were applied throughout the experiment. The objective of this study is to demonstrate that, in the context of climate change, farmers can improve their resilience by cultivating rainfed sorghum varieties under irrigation during the dry season. Analysis of variance of the results obtained showed that, under such conditions, the S35 sorghum variety nearly tripled its rainfed yield (5.82 t·ha^-1, compared to 2 t·ha^-1). The study highlights that access to agricultural water is essential for farmers seeking to strengthen their climate resilience. Cultivating sorghum under irrigation also represents an innovation for optimizing the use of hydro-agricultural infrastructure, which is generally reserved for rice and market gardening.

Reviewer Acknowledgements for Journal of Agricultural Science, Vol. 18, No. 7

Wed, 10 Jun 2026 01:13:22 +0000

Reviewer acknowledgements for Journal of Agricultural Science, Vol. 18, No. 7, 2026.