Asian Journal of Agricultural and Horticultural Research

Nanotechnology-enabled Biopesticides: Advanced Formulation Strategies, Target-Specific Delivery Mechanisms, and Translational Challenges in Sustainable Crop Protection

Manabendra Debnath — 2026-06-09

Global food security faces mounting pressure from crop-destroying pests and the deeply entrenched reliance on synthetic chemical pesticides that, despite decades of use, are generating accelerating resistance across major pest taxa, widespread ecotoxicological harm to non-target organisms including pollinators and soil biota, and tightening regulatory restrictions in key agricultural markets. Biopesticides — encompassing microbial agents, botanically derived compounds, and semiochemicals — offer a fundamentally more targeted and biodegradable alternative; yet their widespread field adoption has been constrained by rapid photodegradation under UV exposure, thermal instability, shortened residual activity, inconsistent performance under variable seasonal and edaphic conditions, and persistent challenges in formulation shelf life and manufacturing consistency. The integration of engineered nanoscale delivery platforms with biologically active ingredients offers a transformative strategy to overcome these barriers simultaneously. By encapsulating or functionalising biopesticide compounds within purpose-built nanocarriers, it becomes possible to shield active ingredients from premature environmental degradation, programme controlled and stimulus-responsive release profiles, enhance foliar retention and cuticular penetration, and achieve target-specific delivery while minimising off-target exposure to beneficial organisms. This review provides a systematic and critical assessment of nanotechnology-enabled biopesticide development, with three explicit objectives: (i) to evaluate the principal nanoformulation platforms — including biodegradable polymeric nanoparticles, nanoemulsions, solid lipid carriers, inorganic layered double hydroxides, and RNAi-based nanoformulations — in terms of their physicochemical mechanisms, efficacy evidence, and comparative limitations; (ii) to critically analyse the environmental fate, ecotoxicological risks, and resistance management implications of these delivery systems under realistic field conditions; and (iii) to identify the translational barriers — regulatory, economic, and socio-technical — that currently impede the scaling and deployment of nano-biopesticides in diverse agricultural contexts. Environmental fate of nanocarriers in soil and aquatic compartments, effects on non-target microbial communities, and regulatory approval pathways across major jurisdictions are critically assessed. Current limitations of the field — including inadequate long-term ecotoxicological data, the absence of harmonised nano-specific risk frameworks, high production costs, and limited farmer-level evidence — are explicitly identified. Realising the transformative promise of nano-biopesticides will require coordinated advances in regulatory science, cost-competitive manufacturing, multi-season field validation, and inclusive science-policy dialogue with farming communities and development organisations.

Efficacy of Insecticides against Red Pumpkin Beetle (Aulacophora foveicollis) in Summer Squash at Gauradaha, Jhapa, Nepal

Bhimlal Bhandari — 2026-06-01

Red Pumpkin Beetle (RPB), (Aulacophora foveicollis), is a major destructive insect pest of summer squash, leading to severe vigor and yield loss. A field experiment was conducted in Gauradaha Agriculture Campus in 2024 to assess the comparative efficacy of various chemical insecticides for the management of RPB in Summer Squash The experiment was conducted on a Randomized Complete Block design (RCBD) with 3 replications and 7 treatments. The treatments subjected to the crop were Azadirachtin 300 ppm (3ml/L), Spinosad 45% SC (0.4 ml/L), Cypermethrin 10% EC (1.5 ml/L), Beauveria bassiana 1.15% WP (3 g/L), Malathion 50% EC (2 ml/L), Chlorantraniliprole 18.5% w/w (0.4 ml/L), and water (1.2 L/plot) as a control. The results showed significant differences among treatments in reducing RPB population after each spray (P<0.05). The cypermethrin led to lower RPB population with an average of 1.59, 1.59, and 1.44 after the first, second, and third spray, respectively. The highest Population Reduction Over Control (PROC) was also observed with cypermethrin in both the second and third spray applications, at 23.07% and 14.54%, respectively. Beauveria bassiana was the second most effective treatment in controlling the population of PROC of 12.55, 16.32, and 8.72 after the first, second, and third spray, respectively, along with the lowest average RPB count at first (1.51) and second spray (1.57). Spinosad followed them with PROC value 22.98%, 8.72%, 10.22% and average RPB count of 1.64, 1.66, and 1.62, respectively. Findings suggested a significant impact of insecticidal treatments on crop yield, where the highest yield was observed in Cypermethrin-treated plots (28.21 Mt/ha), followed by Spinosad (26.06 Mt/ha) and Beauveria bassiana (20.36 Mt/ha). The lowest yield was recorded in the untreated control (11.66 Mt/ha). Overall, the study suggests the use of cypermethrin, Spinosad, and Beauveria bassiana for managing RPB in Summer squash in the local context of Gauradaha.

The Determinants of Food Security of Smallholder Vegetable Farmers in Eswatini

S. Sibandze Sikelela — 2026-06-20

Background: Agriculture supports rural livelihoods, employment creation and household food provision in Eswatini, yet food insecurity persists among rural farming households. Smallholder vegetable production is an important enterprise because it can contribute to household income, food availability and dietary diversity. However, empirical evidence on the determinants of food security among vegetable farmers in Eswatini remains limited.

Aim: This study analysed the determinants of food security among smallholder vegetable farmers in Eswatini.
Methods: The study targeted smallholder vegetable farmers contracted with the National Agricultural Marketing Board (NAMBoard). A random sample of 365 vegetable farmers was drawn from a population of 946 contracted farmers across the four administrative regions of Eswatini. Cross-sectional data were collected through face-to-face interviews using a structured questionnaire. Household food security status was measured using the Food Security Index, while the determinants of food security were estimated using a logit regression model.

Results: The results show that 86 farmers (21.77%) were severely food insecure, 129 farmers (32.66%) were moderately food insecure and 180 farmers (45.57%) were food secure. The logit regression results indicate that age, household size, farming experience, education level, off-farm income and annual household income significantly influenced the probability of being food secure. Age and household size had negative effects, whereas farming experience, education level, off-farm income and annual household income had positive effects.

Conclusion and Recommendation: The study concludes that food security among smallholder vegetable farmers is associated with demographic, human-capital and income-related factors. It recommends strengthening farmer education, youth-focused agricultural programmes, income diversification opportunities and market-oriented support to improve household food security among vegetable farmers in Eswatini.