The study, conducted by Yuejin Peng, Qingqing Liu, Yangshan Hu, Junmin Liang, Ziqian Yang and Lujia Yang, and published in BMC Plant Biology, focused on two fungal isolates recovered from maize: Purpureocillium lilacinum strain PL6 and Beauveria bassiana strain YC-1. Both species are well known in agricultural circles, particularly Beauveria bassiana, which has a long history as an insect-killing fungus used in biological pest control. What makes the new work notable is the combination of approaches the team brought to bear. Rather than simply testing whether the fungi could fight rust, the researchers combined morphological observation, molecular phylogenetic identification, whole-genome sequencing, laboratory bioassays and insect pathogenicity tests to build a comprehensive picture of what these organisms are and what they can do.

The genomic work formed the technical backbone of the study. Using Illumina sequencing, the team assembled draft genomes of 36.68 megabases for PL6 and 33.05 megabases for YC-1. These genome sequences allowed the researchers to peer into the genetic machinery that might underpin the fungi’s beneficial properties. Annotation with the dbCAN3 pipeline, a standard tool for identifying genes encoding carbohydrate-active enzymes, revealed 187 such genes in PL6 and 137 in YC-1. Carbohydrate-active enzymes, often abbreviated as CAZymes, are proteins that break down or modify complex carbohydrates, and in plant-associated fungi they are frequently involved in colonizing plant tissue, degrading pathogen cell walls, or establishing endophytic lifestyles within host plants.

Perhaps even more intriguing were the secondary metabolite biosynthesis gene clusters predicted by the antiSMASH algorithm. The analysis identified 34 such clusters in PL6 and 32 in YC-1, including clusters associated with polyketide synthases, nonribosomal peptide synthetases and terpene biosynthesis. These gene families are responsible for producing some of the most biologically active natural compounds known to science, including antibiotics, toxins and signaling molecules. In biocontrol fungi, secondary metabolites often serve as the chemical weapons that suppress competing pathogens or subvert insect hosts. The abundance and diversity of these clusters in both strains suggests a rich reservoir of unexplored chemistry that could be harnessed for agricultural applications, and it gives researchers a genetic roadmap for future work on identifying the specific compounds involved.

The greenhouse-scale bioassays delivered the headline results. The researchers applied the fungi through root-drench inoculation, a delivery method in which a liquid suspension of the beneficial fungus is applied to the soil around the plant roots, allowing the endophyte to colonize the plant from within. Under the controlled conditions used in the study, both strains restricted the development of southern corn rust. At 24 days post-inoculation, disease incidence remained below 4 percent in plants treated with PL6, while plants treated with YC-1 showed disease incidence of approximately 21 percent. In the untreated control group, by contrast, nearly 48 percent of plants had developed the disease by the same time point.

To quantify disease progression more rigorously, the team calculated the area under the disease progress curve, or AUDPC, a standard epidemiological measure that integrates disease severity over time rather than relying on a single snapshot. The AUDPC dropped from 87.12 in the untreated control to 20.92 following YC-1 treatment and 10.58 following PL6 treatment. Those figures translate into reductions of 76.0 percent and 87.9 percent respectively, a striking level of protection for a disease that typically demands repeated fungicide applications. The magnitude of the PL6 effect in particular suggests that this strain could be a serious candidate for development as a commercial biocontrol agent, although the authors are careful to note that the results come from controlled conditions and that field performance remains to be demonstrated.

What elevates the study beyond a straightforward disease-suppression trial is its dual-purpose angle. Because Beauveria bassiana is already celebrated as an entomopathogenic fungus, the researchers also tested whether their isolates could attack insect pests, specifically fifth-instar larvae of Spodoptera frugiperda, the fall armyworm, another globally feared maize pest. In 10-day bioassays, larval survival was approximately 73 percent with YC-1 and 83 percent with PL6, corresponding to mortality of roughly 27 percent and 17 percent respectively. YC-1, as expected for a species with a strong entomopathogenic pedigree, proved the more lethal of the two against the caterpillars, while PL6 was clearly the stronger rust suppressor. The finding that a single fungal resource could contribute to managing both a foliar rust disease and a lepidopteran pest is precisely the kind of multifunctionality that integrated pest management programs prize.

The concept of endophyte-mediated biocontrol is gaining momentum across plant pathology. Endophytic fungi inhabit the internal tissues of plants, often without causing any symptoms, and in many cases they confer benefits to their hosts, ranging from enhanced stress tolerance to induced systemic resistance against pathogens. When an endophyte establishes itself inside a plant, it can prime the plant’s own defense signaling pathways, including those mediated by salicylic acid and jasmonic acid, two key hormones in plant immunity. It can also compete directly with pathogens for space and resources, or produce antimicrobial compounds in situ. The rich arsenal of secondary metabolite gene clusters documented in PL6 and YC-1 hints that such chemical warfare may be part of the mechanism at work, though the study’s genomic characterization stops short of confirming which specific compounds are deployed during rust suppression.

The implications for maize farming could be significant. Southern corn rust has been expanding its reach in recent years, aided by warming climates and long-distance spore dispersal, and growers in affected regions often face the prospect of multiple fungicide sprays per season. A biological approach based on root-drench inoculation with endophytic fungi could reduce that chemical load, fit neatly into organic and low-input production systems, and offer a tool against fall armyworm at the same time. The genome-reported nature of the two strains is also an asset for regulatory and development pipelines, because whole-genome sequences help clarify strain identity, screen for unwanted virulence or toxin genes, and support quality control in commercial production. The work was supported by the National Natural Science Foundation of China, the Natural Science Foundation of Yunnan Province and the Yunnan Provincial Department of Education Scientific Research Fund Project.

There remain important caveats and next steps. The disease and insect assays were performed under controlled laboratory and greenhouse conditions, and real-world fields present far more variable environments, competing microbes, and pathogen pressures. The moderate insect mortality observed, particularly for PL6, suggests these strains would likely serve as components of an integrated management strategy rather than stand-alone silver bullets. Nevertheless, the combination of strong rust suppression, documented genomes, abundant biosynthetic potential and demonstrated activity against a major pest makes PL6 and YC-1 a compelling proof of concept. As agriculture searches for ways to sustain productivity while weaning itself off synthetic chemistry, studies like this one show that the answers may already be living inside the crops themselves, waiting to be sequenced, understood and deployed.

Subject of Research: Genomic characterization of endophytic fungi as biocontrol agents against southern corn rust and fall armyworm in maize

Article Title: Genomic characterization and biocontrol potential of the endophytic Purpureocillium lilacinum PL6 and Beauveria bassiana YC-1 against southern corn rust

Article References: Peng, Y., Liu, Q., Hu, Y., Liang, J., Yang, Z., & Yang, L. (2026). Genomic characterization and biocontrol potential of the endophytic Purpureocillium lilacinum PL6 and Beauveria bassiana YC-1 against southern corn rust. BMC Plant Biology. https://doi.org/10.1186/s12870-026-10090-y

Image Credits: AI Generated

DOI: 10.1186/s12870-026-10090-y

Keywords: Purpureocillium lilacinum, Beauveria bassiana, southern corn rust, Puccinia polysora, endophytic fungi, biological control, maize, whole-genome sequencing, secondary metabolites, Spodoptera frugiperda, fall armyworm, plant pathology

The fall armyworm, Spodoptera frugiperda, is a multivoltine moth native to the Americas whose larvae devour an extraordinary range of vegetation, including economically critical crops such as corn, sorghum, and sugarcane. Since 2016, the species has invaded numerous countries across Africa, Asia, and Oceania, cementing its reputation as one of the world’s most destructive agricultural pests. Its population dynamics follow dramatic boom-and-bust cycles, and a key driver of those crashes is a naturally occurring pathogen: Spodoptera frugiperda multiple nucleopolyhedrovirus, or SfMNPV. This species-specific baculovirus is lethal to the armyworm and has even been deployed as a biopesticide. When a larva ingests viral occlusion bodies — protein-encased packages of double-stranded DNA visible under a light microscope — the virus proliferates inside its body until the larva literally liquefies, splattering virus-laden fluid onto the foliage where other larvae feed and continue the infection cycle.

But there is a second, darker route of transmission: cannibalism. Fall armyworms are notoriously cannibalistic, particularly in their later larval stages, and when a healthy larva consumes an infected conspecific, it risks swallowing a lethal dose of virus along with the meal. Researchers at the heart of the new study, led by Kale Rougeau and Bret Elderd, wanted to know how two major climate change stressors — rising temperature and declining resource quality — might alter this cannibalistic behavior and, in turn, the spread of disease. Rather than testing each stressor in isolation, they designed a fully factorial experiment combining three temperature regimes, four diet treatments, and two infection statuses, for a total of 480 individual larvae across 24 treatment combinations.

The temperature treatments were carefully calibrated using a thermal performance curve for the species. A cooler regime of 26°C days and 16°C nights approximated the armyworm’s thermal minimum, an optimal regime of 31°C and 21°C matched its thermal optimum, and a warmer regime of 34°C and 26°C sat just below its thermal maximum. To simulate the nutritional consequences of climate change, the team manipulated the protein-to-carbohydrate ratio of artificial diets. Rising atmospheric carbon dioxide dilutes nitrogen in plant tissue, lowering the protein available to herbivorous insects — a phenomenon known as nutrient dilution. The researchers created a high-protein diet with a 5:1 protein-to-carbohydrate ratio, an equal 1:1 diet, and a low-protein 1:5 diet, alongside a standard commercial diet as a baseline. Larvae fed their assigned diet for one full instar before entering the behavioral trials.

The experimental setup was elegantly simple. Fourth-instar larvae, starved for 24 hours, were placed in Petri dish arenas with either an infected or uninfected third-instar conspecific and a cube of their assigned diet. Infected conspecifics had received a lethal dose of 1 × 10⁵ SfMNPV occlusion bodies per microliter, and verification larvae confirmed that 100 percent of infected individuals died of viral liquefaction while no uninfected controls showed contamination. The arenas were checked for cannibalism at 1, 2, 4, 8, 16, and 24 hours, and surviving fourth instars were then reared through pupation so the team could measure fitness via pupal mass, a well-established proxy for fecundity in this species.

The results were striking. Cannibalism rates climbed steadily with temperature across every diet type, and the best-fit statistical model — selected using the small-sample-corrected Akaike Information Criterion — included a three-way interaction among temperature, diet, and conspecific infection status, accounting for 67 percent of the cumulative model weight. Temperature carried a significant positive effect, with a slope of 0.307 and a p-value below 0.0009. Larvae on the low-protein diet showed the highest overall odds of cannibalism, suggesting they were supplementing missing protein by eating their neighbors. Intriguingly, at cooler temperatures on the low-protein diet, infected conspecifics were cannibalized less readily than healthy ones — yet on the standard diet, infected individuals were more likely to be eaten regardless of temperature. Behavior, it turns out, depends on the full environmental context, not any single stressor.

What about disease? Among larvae that actually cannibalized infected conspecifics, temperature alone best predicted whether infection took hold, with a significant but modest positive slope of 0.117 — roughly one-third the size of the temperature effect on cannibalism itself. Only two individuals across all treatments became infected without consuming their conspecific, likely through trace viral contamination, and these were excluded so the analysis focused purely on cannibalism-driven transmission. The relatively weak direct effect of temperature on infection risk may reflect a biological quirk: each time a larva molts, it sheds the lining of its midgut, expelling recently consumed viral particles before the infection can establish. At higher temperatures, faster development and more frequent molting may partially counterbalance the elevated metabolic costs that otherwise leave insects more vulnerable to lethal infection.

The fitness results added another layer of nuance. Among the 199 moths that successfully eclosed, pupal mass declined with warming temperatures on all macronutrient-manipulated diets but remained stable on the standard diet, and the temperature-by-diet interaction model captured 85 percent of the model weight. Counterintuitively, larvae on the low-protein diet achieved the highest pupal masses — averaging about 184 milligrams compared with roughly 123 milligrams for high-protein larvae — possibly because cannibalism conferred a nutritional advantage to protein-deprived individuals. Notably, neither cannibalism status nor the infection status of the consumed conspecific predicted pupal mass, indicating no detectable fitness cost from sub-lethal viral loads among survivors.

The broader implications are twofold. First, as climate change brings more extreme heat and carbon-driven nutrient dilution degrades plant quality, cannibalism in fall armyworms — and perhaps in other readily cannibalistic herbivorous insects — is likely to increase, driven by a combination of heightened energy demands and protein scarcity. Second, because cannibalism is a transmission route for pathogens, more cannibalism could mean more disease spread, compounded by a slight direct increase in infection risk from temperature alone. Yet the picture is not uniformly grim for the virus: eating an infected conspecific does not always lead to infection, so cannibalism can also remove pathogens from a population. The study’s authors point out that contrasting systems behave differently — warmer temperatures reduce viral transmission in gregarious western tent caterpillars, which disperse rather than congregate in the heat, and diminish fungal infection in spongy moths under warmer, drier conditions.

What happens next for the fall armyworm may depend on geography as much as biology. Climate projections suggest the pest will proliferate in some regions while facing local extinction in areas already near its critical thermal maximum. Changes in cannibalistic behavior and baculovirus transmission could further shape how the species spreads globally, altering both the intensity of crop damage and the efficacy of viral biopesticides. The research team suggests that field experiments and in silico modeling of these coupled dynamics are natural next steps. For now, the message is clear: climate change does not simply make the world hotter — it makes hungrier, more desperate creatures out of the insects that threaten our food supply, and in doing so, it quietly redraws the map of disease.

Subject of Research: Effects of temperature and diet quality on cannibalism and baculovirus transmission in fall armyworm larvae

Article Title: We Are Dying to Eat You: Cannibalism and Disease Transmission Under Global Climate Change

Article References: Rougeau, K., & Elderd, B. D. (2026). We Are Dying to Eat You: Cannibalism and Disease Transmission Under Global Climate Change. Ecology and Evolution, 16(10), Article e74403. https://doi.org/10.1002/ece3.74403

Image Credits: AI Generated

DOI: 10.1002/ece3.74403

Keywords: fall armyworm, cannibalism, baculovirus, climate change, disease transmission, nutrient dilution, insect behavior, host-pathogen dynamics, agricultural pest, pupal mass, temperature, ecology

To understand why this matters, it helps to start with the chemistry. Since Watson and Crick described the double helix in 1953, DNA has been imagined as a linear molecule in which adenine pairs with thymine and cytosine pairs with guanine. But guanine-rich sequences can do something unusual: four guanine bases can associate in a square, coplanar arrangement called a G-quartet, held together by eight Hoogsteen hydrogen bonds, a bonding pattern first described by biochemist Arthur Hoogsteen in 1963. When two or more of these G-quartets stack on top of one another, they form a G-quadruplex. Monovalent cations such as potassium, sodium and ammonium nestle in the central channel of the stack and stabilize the structure. Depending on the number of stacked quartets, the length of the connecting loops and the polarity of the strands, G-quadruplexes adopt parallel, antiparallel or hybrid conformations, giving them a remarkable structural versatility.

The evidence that these structures exist inside living cells is now strong. Using the G4-specific antibody BG4, researchers visualized G-quadruplex foci in human cell lines, and the signals vanished after DNase treatment and multiplied when cells were exposed to pyridostatin, a small molecule that stabilizes G4s. G4-binding proteins such as the helicase DHX36, the fly protein LARK and the yeast helicase Pif1 provide further indirect proof of their presence in vivo. Genomewide, the picture is striking. Roughly 700,000 potential G4-forming sequences have been predicted in the human genome, and across 37 surveyed species the number and density of these motifs increased with evolutionary complexity. Crucially, the sequences are not scattered randomly: they cluster at replication origins, promoters, telomeres and untranslated regions, exactly the places where a regulatory element would be expected to sit.

That nonrandom distribution underpins the biological roles of G-quadruplexes. In mammalian genomes, 80 to 90 percent of replication origins are GC-rich and capable of forming G4s, and these structures can act both as barriers that helicases must unwind to prevent fork collapse and as recognition sites that recruit initiation factors such as the origin recognition complex and Rif1. In promoters, G4s can either boost or suppress transcription by altering how transcription factors bind. The classic example is the human oncogene c-Myc, whose expression dropped when cells were treated with the G4 ligand TMPyP4 and fell dramatically when the promoter G4 was disrupted by CRISPR-Cas9 editing. Recent work has even shown that promoter G4s serve as common binding hubs for many transcription factors. At telomeres, the single-stranded G-rich overhang folds into G4s that modulate telomerase activity and telomere length, while RNA G-quadruplexes in untranslated regions regulate translation, splicing and mRNA stability.

Plants have their own distinctive G4 landscape. An analysis of 15 sequenced plant genomes, from Arabidopsis thaliana and rice to mosses and lycophytes, revealed that more than 90 percent of plant G4s contain only two G-quartets, a profile quite different from the human genome, where three-quartet structures dominate. The density of predicted G4-forming sequences in monocotyledons was five to ten times higher than in dicotyledons, and G4 motifs were even found in chloroplast and mitochondrial DNA, with mitochondrial DNA showing roughly three times the G4 frequency of nuclear and chloroplast genomes. In Arabidopsis, rice and maize, these motifs concentrate around transcription start sites, 5-prime untranslated regions and other regulatory zones, hinting at cis-regulatory functions in gene expression.

Functional studies in plants have delivered some of the most vivid demonstrations of G4 biology. The first RNA G4 identified in a living plant cell sat in the 5-prime untranslated region of the DNA damage response gene ATR, where it acted as a translational repressor. Another RNA G4 in the untranslated region of SMXL4/5 suppresses translation and restricts phloem differentiation, directly linking a folded RNA structure to vascular development. Perhaps most strikingly, the RNA G4 in the 3-prime untranslated region of the drought-induced dehydrin gene HIRD11 inhibits its translation; when the G4 motif was mutated, Arabidopsis roots grew significantly longer. Even more intriguingly, when researchers compared the nucleotide composition of transcriptomes across 1,000 plant species, they found that plants from cold climates carried G-rich transcriptomes prone to forming RNA G4s, and in Arabidopsis these cold-responsive G4s stabilized mRNAs and helped regulate growth at low temperatures. G4s in maize have also been tied to hypoxia, oxidative stress and energy status, suggesting that these structures are deeply woven into how crops cope with a changing environment.

Insects, meanwhile, offer both the best model systems and the most direct agricultural stakes. In Drosophila, the first predicted G4 was found in the HeT-A retrotransposon at chromosome ends, and subsequent work showed G4 motifs overlapping replication origins, common in all centromeres, and enriched in long intergenic noncoding RNAs, introns and promoters, with an improved G4-seq method detecting 22,511 such sequences genomewide. G4 signals localize to heterochromatin in salivary gland polytene chromosomes and are weaker in germline stem cells, implying a role in cell differentiation. The Drosophila homolog of the helicase DHX36 has been crystallized bound to a G4, revealing at atomic resolution how the enzyme unfolds the structure, and mutations in pif1 cause chromosome segregation defects consistent with unresolved G4s stalling replication forks.

Outside the fruit fly, the silkworm Bombyx mori has become the showcase for insect G4 biology. Its telomeric repeat d[TAGG(TTAGG)3], conserved across many insects, folds into a chair-type intramolecular G4 that is more stable in sodium than in potassium solution. The silkworm genome harbors nearly 24,000 predicted G4s, and the first insect G4 shown to regulate transcription was found in the promoter of BmPOUM2, a gene governing development. The G4-binding protein LARK binds this motif to boost transcription, and CRISPR-Cas9 knockout of LARK causes embryonic lethality with broad changes in cuticle and pigment gene expression. A G4 in the promoter of the acyl-CoA binding protein gene BmACBP regulates lipid metabolism: when fifth-instar larvae were treated with the G4-stabilizing ligand pyridostatin, BmACBP expression and triacylglycerol levels dropped, fat body mass shrank, and larval growth and metamorphosis slowed. A G4 in the promoter of the silk gland factor SGF1 acts as a positive regulator of silk protein production, and its knockout reduced silk output in mutant larvae.

The pest control implications come into sharpest focus in the fall armyworm, Spodoptera frugiperda, a globally destructive crop pest. Genomewide analysis identified 387,875 predicted G4-forming sequences, nearly 67 percent of them upstream of start codons, and the genes carrying promoter G4s were enriched for metabolic pathways, especially xenobiotic metabolism by cytochrome P450 enzymes. Treatment with the G4 ligand N-methyl mesoporphyrin IX suppressed P450 expression and enzyme activity and increased larval mortality. In the corn earworm Helicoverpa zea, a transposon-inserted G4 in the promoter of the detoxification gene CYP321A1 acts as a silencer, and destroying it or stabilizing it with NMM reduced the promoter’s response to plant toxins. Because insects rely on P450s, glutathione-S-transferases and carboxylesterases to survive both plant allelochemicals and pesticides, these findings open a concrete path: G4 ligands could be deployed either as standalone insecticides that disrupt the G4s of development genes, producing abnormal larvae, or as pesticide sensitizers that knock down detoxification genes and restore the potency of existing chemicals.

The review’s authors sketch three strategies for turning this biology into practice. First, cell-permeable G4 ligands could be screened or designed to target the specific structures of pest development genes, exploiting the fact that G4 structural polymorphism offers ligand specificity. Second, G4 ligands could accompany conventional insecticides, either destabilizing the G4s that drive detoxification gene expression or stabilizing them so that transcription factors cannot bind, thereby synergizing with the pesticide. Third, and perhaps most elegant, plants themselves could be engineered to produce higher levels of natural G4-binding compounds, so that feeding pests ingest ligands that disrupt their own gene regulation. Plant-derived molecules such as the flavonoids fisetin and kaempferol and the alkaloids chelerythrine and berberine already bind G4s and are being explored as low-toxicity anticancer leads, and the same chemistry could be redirected toward agriculture. No G4-based pesticide has yet reached the field, and large-scale screening of plant extracts has only just begun, but the underlying logic is compelling: unlike organophosphates or hormone analogs that hit broad physiological processes, a molecule aimed at a single G4 structure in a pest’s DNA or RNA could, in principle, be exquisitely species-specific, sparing beneficial insects and leaving the environment largely untouched. As more G4s are mapped and their regulatory functions confirmed, the humble four-stranded guanine quartet may prove to be one of the most unexpected weapons in the fight to protect the world’s crops.

Subject of Research: G-quadruplex nucleic acid structures and their regulatory roles in plants and insects with applications in pest control

Article Title: G-quadruplex structure in plants and insects and potential applications in pest control

Article References: G-quadruplex structure in plants and insects and potential applications in pest control. (n.d.). https://doi.org/10.1007/s44297-025-00047-2

Image Credits: AI Generated

DOI: 10.1007/s44297-025-00047-2

Keywords: G-quadruplex, DNA structure, RNA G-quadruplex, plants, insects, pest control, silkworm, fall armyworm, cytochrome P450, G4 ligands, gene regulation, crop protection

The research team deliberately chose three districts that span Uganda’s fragmented tenure landscape. Under the Land Act of 1998, amended in 2010, Uganda formally recognizes four tenure systems: freehold, leasehold, Mailo, and customary. Customary tenure dominates in Eastern Uganda, including Mbale and Bukedea, while Luwero in the central Buganda region hosts a mix of customary, freehold, and Mailo arrangements. Mbale, with a population of 410,300 across five rural sub-counties, is characterized by subsistence farming and widespread land fragmentation. Bukedea, with 112,213 rural residents spread across 14 sub-counties, experiences persistent tenure insecurity and recurrent environmental shocks. Luwero, located about 64 kilometers north of Kampala, has a population of 456,958, with 81 percent of households engaged in subsistence agriculture and only 21 percent living in urban areas. This diversity allowed the researchers to compare how different governance regimes translate into food outcomes within a single national context, an approach few studies have attempted.

Methodologically, the study was rigorous for a field survey. The sample size of 398 was calculated using Yamane’s formula applied to a target population of 51,046 individuals across the three districts, with a precision level of 0.05. Participants were adult farmers aged 18 and above who were responsible for household land use and agricultural decision-making. A multi-stage sampling strategy stratified sub-counties by geographic location and agricultural productivity, then randomly selected villages and systematically sampled households within them. Data were collected through a structured, expert-reviewed, and pretested questionnaire administered face-to-face by trained enumerators, with internal consistency assessed by Cronbach’s alpha at an acceptable value of 0.75. Analysis proceeded in three phases in Stata 18: univariate description, bivariate cross-tabulation with Pearson’s chi-square tests, and finally a binary logistic regression model reporting adjusted odds ratios with 95 percent confidence intervals, adjusted for confounders including household size, education level, and access to agricultural land.

The headline result is stark. Households with sufficient land for food production had roughly 22 times higher odds of being food secure than those without adequate land (adjusted odds ratio 22.08, 95 percent confidence interval 6.25 to 77.97). In the bivariate analysis, 96.2 percent of households reporting insufficient land were food insecure, compared with 61.7 percent food security among those with adequate land, a difference significant at p less than 0.001. How land was acquired mattered nearly as much as how much of it there was. Land inherited from family members conferred about 6.6 times higher odds of food security (AOR 6.62, 95 percent CI 1.12 to 39.18), while newly acquired land was associated with roughly fivefold higher odds (AOR 4.99, 95 percent CI 1.14 to 21.85). Inheritance, the authors note, typically comes with socially recognized claims that support continuity in land use and the intergenerational transfer of agricultural knowledge.

Two agronomic variables produced even larger effects than tenure itself. Access to irrigation was associated with about 27 times higher odds of food security (AOR 27.39, 95 percent CI 2.52 to 297.55), despite irrigation remaining rare across the study sites; only 16.2 percent of food-secure households reported irrigation access versus 3.2 percent of food-insecure ones. Adoption of farming technologies and risk management practices within the previous five years was reported by 39.6 percent of food-secure households but just 4.4 percent of food-insecure households, and it carried an adjusted odds ratio of 14.71 (95 percent CI 1.37 to 158.23). In a country where rainfall patterns are becoming increasingly erratic and prolonged dry spells more common, these numbers suggest that water control and technology adoption function as powerful protective factors against production failure, stabilizing yields and enabling year-round cultivation in ways that rain-fed subsistence farming cannot.

On the destructive side of the ledger, pest and disease outbreaks emerged as the single most damaging factor measured. Households affected by outbreaks, including infestations of Fall Armyworm, a caterpillar pest that devastates maize and other staples, had dramatically reduced odds of food security (AOR 0.01, 95 percent CI 0.00 to 0.11). In the bivariate analysis, only 55.5 percent of pest-affected households were food secure compared with 83.8 percent of unaffected households. The authors point to prior Ugandan research reporting that 64 percent of farmers in Kamuli and 82 percent in Namutumba regarded Fall Armyworm as a serious threat to production. The implication is urgent: integrated pest management, timely extension services, and access to resistant crop varieties are not optional extras but core components of any food security strategy in the region.

The tenure typology itself also shaped outcomes in ways consistent with economic theory. Households under freehold and customary systems were significantly more food secure than those under leasehold or Mailo arrangements. The authors attribute this to the greater perceived tenure security and autonomy over land use under freehold and customary regimes, which encourage long-term investment in soil conservation, irrigation infrastructure, and tree planting. Leasehold and Mailo systems, by contrast, are often characterized by unclear ownership rights, limited user control, and disputes that discourage investment in productivity-enhancing inputs. This aligns with a broader literature linking tenure insecurity to land degradation, reduced access to credit, and suboptimal land use, and with recent Ugandan evidence that tenure insecurity remains a binding constraint on productivity, particularly in Mailo-affected regions such as Luwero.

Land loss tells the mirror-image story. Among households reporting changes in land access, 44.7 percent of food-secure households had gained land, whereas 70.3 percent of food-insecure households reported losing it, a difference significant at p equal to 0.048. Land disputes were reported by 46.2 percent of food-insecure households compared with 33.3 percent of food-secure ones, and negative perceptions of the tenure system’s effect on food access were more prevalent among the food insecure (38.6 percent versus 25.0 percent, p equal to 0.005). In an agrarian economy, land is simultaneously the means of food production, a source of income, and a form of social identity; losing it through eviction, boundary conflict, or market displacement removes the productive base with little possibility of substitution. Notably, households reporting no conflicts with neighbors showed reduced odds of food insecurity (AOR 0.15, 95 percent CI 0.02 to 0.92), underscoring how local social relations mediate tenure security.

Perhaps the most sobering finding concerns gender. Female-headed households constituted only 10.6 percent of landowners in the sample, even though women are central to food production across the study region. Male-headed households dominated land ownership and were more likely to be food secure, a pattern the authors link to structural gender barriers that limit women’s access to and control over land. The study joins a growing body of work, from Ghana to Mozambique to Malawi, showing that gendered tenure access shapes food and nutrition security, particularly under urbanization pressure. The authors argue that addressing these inequities requires comprehensive strategies including joint land titling, legal empowerment, and the integration of women into land governance structures, rather than piecemeal interventions.

The study’s policy implications are concrete. The authors recommend reforming leasehold and Mailo tenures through legal harmonization and efficient land administration, scaling up the issuance of Certificates of Customary Ownership, facilitating joint titling, strengthening district-level dispute resolution, and improving legal literacy among land users. In parallel, they call for investment in small-scale irrigation infrastructure, integrated pest management, improved seeds, and climate-smart technologies, with extension services expanded especially in tenure-insecure regions. They also urge that land tenure reform be mainstreamed as a cross-cutting issue in Uganda’s National Development Plans. The authors acknowledge limitations: the cross-sectional design cannot establish causation, self-reported data may carry recall bias, purposive district selection limits national generalizability, and food security was measured as a composite rather than disaggregated into availability, access, utilization, and stability. Still, the core message stands out with unusual clarity. In rural Uganda, the path to resilient food systems runs directly through land governance, and a family’s dinner table is secured, or emptied, by the fine print of who holds the land and how surely they hold it.

Subject of Research: The impact of land tenure systems on household food security in rural Uganda

Article Title: Land tenure systems and their impact on food security in Mbale, Bukedea, and Luwero Districts, Uganda

Article References: Wabusa, F. D., Lutale, A. J., & Oino, P. G. (2025). Land tenure systems and their impact on food security in Mbale, Bukedea, and Luwero Districts, Uganda. BMC Agriculture, 1(1), Article 20. https://doi.org/10.1186/s44399-025-00018-6

Image Credits: AI Generated

DOI: 10.1186/s44399-025-00018-6

Keywords: land tenure, food security, Uganda, customary tenure, Mailo tenure, irrigation, Fall Armyworm, land inheritance, gender equity, smallholder farming, land disputes, agricultural technology

Researchers at Ladoke Akintola University of Technology in Ogbomoso evaluated 32 maize hybrids, including 26 experimental top-cross hybrids developed by the Maize Improvement Programme of the International Institute of Tropical Agriculture and six commercial checks, across two planting dates in the 2024 season. The trials were deliberately left exposed to natural fall armyworm infestation, and the plants received no insecticide against the pest. The team scored foliar damage at four, eight, and twelve weeks after sowing using a modified Davis rating scale, alongside a full suite of agronomic measurements from flowering time to husk cover, plant height, and grain yield adjusted to standard moisture.

The standout performer was hybrid G1, bred from the cross FAWSYN-1/(TZLComp. 1 C6-W-39-1-1)-B-B, which produced 5,223.3 kilograms of grain per hectare across environments, a 26.8 percent yield advantage over the best commercial check, Oba Super 9. Roughly 30.7 percent of the tested hybrids outyielded that top check, and eight of the 26 experimental hybrids beat all six commercial controls. The new hybrids also showed improvements of 9 to 13 percent in husk cover, plant aspect, and ear aspect ratings, 5 to 12 percent better tolerance of southern corn leaf blight and ear rot, and 12 to 35 percent improved tolerance of foliar fall armyworm damage across the scoring intervals.

The statistical architecture of the trial revealed as much about the environment as about the genetics. Analysis of variance showed highly significant differences among hybrids, environments, and their interactions for grain yield and most agronomic traits. When the total variation in grain yield was partitioned, the environment accounted for 54 percent, hybrids for 21 percent, and the hybrid-by-environment interaction for 11 percent. In other words, where and when the maize grew mattered more than which hybrid was in the ground, a sobering reminder of how strongly rain-fed African farming systems are governed by weather. The two planting dates produced dramatically different outcomes: grain yield ranged from 715.4 to 3,241.2 kilograms per hectare in the early planting, but from 901.8 to 7,205.3 kilograms per hectare in the later sowing, a gap of more than 2,300 kilograms per hectare between environment means.

The reason for that gap lay in the rainfall record. A prolonged drought between July and August struck the later-planted crop during the critical periods before anthesis and after silking, stretching the anthesis-silking interval from one or two days in the first environment to three to seven days in the second. Maize is notoriously sensitive to moisture stress during flowering and grain filling, and the combined burden of drought and heavy fall armyworm pressure drove yields down in the first planting. The authors note that erratic rainfall, including a cessation of rain after planting that stressed seedlings and excessive rain near maturity that caused lodging, complicated the evaluation, yet the pest pressure remained sufficient to differentiate the hybrids consistently.

Correlation and regression analyses pinpointed which traits actually mattered for yield under pest attack. Grain yield correlated significantly and negatively with foliar fall armyworm damage, plant aspect, and husk cover ratings, meaning that hybrids with cleaner leaves, more compact and appealing plant architecture, and tighter husk coverage yielded more. Plant aspect showed the strongest individual association with yield, explaining 42 percent of its variability in regression analysis, with each unit worsening in the score costing roughly 1,402 kilograms per hectare. Foliar armyworm damage itself explained 13 percent of yield variation, and every unit increase in the damage score reduced grain yield by about 864 kilograms per hectare. Plant height and ear height, by contrast, correlated positively with yield, reflecting the larger leaf area and photosynthetic capacity of taller plants.

The genetic analysis added an important caveat. Broad-sense heritability was moderate for flowering traits and foliar diseases, ranging from 42 to 55 percent, but low, between 3 and 13 percent, for grain yield and fall armyworm damage scores. Environmental variance exceeded genetic variance for every trait measured, and genotypic coefficients of variation were consistently lower than phenotypic ones. This means that much of what breeders observe in any single season reflects the environment rather than stable genetic differences, and the authors caution that these estimates are population- and environment-specific, requiring validation across additional locations and years before broader breeding inferences can be drawn.

To cut through the complexity of selecting for many traits at once, the team applied the genotype by yield times trait biplot, a multivariate technique that ranks hybrids by how well they combine grain yield with each desirable characteristic. The first two principal components captured about 82 percent of the variation, and the analysis identified five hybrids, G1, G9, G21, G18, and G3, as superior combinations of high yield and moderate fall armyworm tolerance. Hybrid G1 and its close relative G9 excelled at pairing yield with low ear rot and Curvularia leaf spot scores, while G21 and G18 combined yield with strong rust tolerance and favorable plant and ear aspects. The same analysis flagged the weakest performers, including the commercial hybrid Oba Super 2, which yielded only 1,502.7 kilograms per hectare.

Notably, the commercial checks revealed how far standard market varieties still lag. Most checks showed consistent baseline susceptibility to fall armyworm, with several leaves bearing holes and lesions across the scoring weeks, while two experimental hybrids, G7 and G19, maintained low, stable damage ratings throughout the season. Among the commercial options, only SAMMAZ 51 stood out as an outlier with meaningful tolerance. The mean damage ratings of all top-cross hybrids stayed below 6 on the nine-point scale, and scores generally declined as plants matured, consistent with earlier reports that infestation pressure eases with crop age.

The study, published in Discover Plants, stops short of recommending the hybrids to farmers just yet. The authors emphasize that the five promising candidates must now advance to multi-location, multi-year uniform yield trials to confirm their adaptation and stability across the derived savanna agroecology and beyond. Still, the findings carry weight for a region where Nigerian farmers harvest an average of just 2.2 tonnes of maize per hectare against a global average of 4.5 tonnes. Host plant resistance, which works through antixenosis, antibiosis, and tolerance, imposes minimal selection pressure on pest populations and, integrated with biological and cultural controls, offers a durable, environmentally safe, and affordable line of defense. In a warming, pest-threatened world, breeding resilience directly into the seed may prove one of the most powerful tools African agriculture has.

Subject of Research: Phenotypic evaluation of fall armyworm-resistant top-cross maize hybrids under rain-fed conditions in a derived savanna agroecology

Article Title: Variation in the phenotypic performance of top-cross fall armyworm resistant maize hybrids under rain-fed growing conditions in a derived savanna agroecology

Article References: Olayinka, A. O., Odewole, A. F., Akande, O. S., Adebayo, P. A., & Ujah, G. O. (2026). Variation in the phenotypic performance of top-cross fall armyworm resistant maize hybrids under rain-fed growing conditions in a derived savanna agroecology. Discover Plants, 3(1), Article 424. https://doi.org/10.1007/s44372-026-00896-3

Image Credits: AI Generated

DOI: 10.1007/s44372-026-00896-3

Keywords: fall armyworm, maize hybrids, host plant resistance, grain yield, derived savanna, Nigeria, plant breeding, GYT biplot, heritability, genotype by environment interaction, Spodoptera frugiperda, food security

The research, led by Tiangang Lu, Mustafa Mhamed and colleagues at China Agricultural University and partner institutions, tackles a problem that has long frustrated computer vision researchers: images taken in real fields are messy. Unlike laboratory photographs of detached leaves on clean backgrounds, field images contain soil, weeds, shadows, overlapping leaves, and wildly variable illumination. Visual symptoms also overlap across conditions. Nitrogen deficiency produces yellowing that can resemble early disease, while the feeding damage of Spodoptera frugiperda, the notorious fall armyworm, can mimic fungal lesions. The team’s answer was to build the entire pipeline from the ground up, starting with data.

At the heart of the framework is a new benchmark called the Corn Leaf Disease Forms dataset, or CLDF, containing 2,903 images captured under genuine field conditions. Rather than lumping all abnormalities into a single disease category, the dataset distinguishes four leaf condition classes: healthy leaves, leaves infected with common rust, leaves showing nitrogen deficiency, and leaves damaged by fall armyworm. This four-way distinction matters agronomically, because each condition demands a different intervention. Rust calls for fungicide timing decisions, nitrogen deficiency points to fertilization management, and armyworm damage triggers insecticide or biological control responses. A system that merely flags a leaf as sick is far less useful than one that tells the grower what kind of sick.

Before any detection model sees the images, the researchers pass them through an advanced image processing enhancement framework, abbreviated AIPEF. This preprocessing stage performs background removal to strip away distracting field clutter, noise reduction to clean up sensor artifacts and compression noise, and image enhancement to sharpen the visual features that distinguish one condition from another. The team employed techniques including simple linear iterative clustering for segmentation of leaf regions from their surroundings. The rationale is straightforward: a detector trained on cleaner, more standardized inputs has an easier job, and the same preprocessing applied at inference time helps the model cope with the chaos of live camera feeds in the field.

The detection engine itself is an enhanced version of a state-of-the-art object detection architecture, named P-YOLOv11s-MD-SiLU. The base YOLO family of models, short for You Only Look Once, performs detection in a single forward pass through the network, which is why it has become the workhorse of real-time agricultural vision. The team’s modifications are technically pointed. They incorporated MobileNetV3, a convolutional backbone designed for mobile devices that relies on depth-wise separable convolutions and squeeze-and-excitation blocks to squeeze maximum accuracy out of minimal computation. They also introduced a modified dynamic SiLU activation function, a variation on the sigmoid linear unit that lets the network modulate its nonlinear responses more flexibly as it learns to separate visually similar symptom classes.

The performance numbers are striking. The proposed model achieved a mean average precision at an intersection-over-union threshold of 0.5, written mAP0.5, of 94.90 percent across the four leaf condition classes. Crucially, it did so while reducing computational cost relative to baseline models, a combination that matters enormously for deployment. A detector that is accurate but too heavy to run on a farmer’s phone is a laboratory curiosity. The authors report that the enhanced model outperformed the baseline configurations it was compared against, delivering the kind of accuracy-to-efficiency ratio that real-world precision agriculture demands.

Deployment was not left as a hypothetical. The trained model was integrated into a mobile augmented reality application, allowing a user to point a phone camera at a corn leaf and receive a real-time diagnosis overlaid on the live image. This is where the lightweight architecture pays off: inference happens on the device, in the field, without requiring a high-bandwidth connection to a remote server. For extension workers and smallholder farmers in regions where fall armyworm is an escalating threat, a tool that turns an ordinary smartphone into an instant plant health diagnostic could compress the gap between symptom onset and management action from days to seconds.

Perhaps the most forward-looking component of the framework is its predictive layer. Using historical environmental observations, the team applied an ARIMA time-series model, a classical statistical method for forecasting based on autoregressive and moving-average patterns in past data, to project future occurrences of each leaf condition. The forecasts are specific. The model indicates increased risks of fall armyworm damage during the 2028 to 2030 period, elevated nitrogen deficiency risk in 2027 and again in 2030, and a peak in common rust occurrence in 2026 followed by a gradual decline through 2030. These are not crystal-ball pronouncements but statistical extrapolations, and their value lies in giving agronomists and policymakers a quantitative horizon for planning seed choices, fertilizer programs, and pest surveillance campaigns.

The integration of detection and forecasting within a single framework reflects a broader shift in agricultural AI. Early deep learning studies in plant pathology focused narrowly on classification accuracy in curated datasets, and many promising models stalled when moved outdoors. The present work follows the path that the field has increasingly taken: build representative field data, engineer the preprocessing to handle environmental noise, optimize the network for the hardware it will actually run on, and then extend the system from reactive diagnosis to proactive prediction. The growth-stage awareness built into the framework acknowledges that the same leaf can present very different symptoms depending on the developmental phase of the plant, a nuance that simpler systems ignore.

The implications extend beyond corn. The architectural recipe, a curated field dataset, a modular enhancement pipeline, a compressed detection network, and a statistical forecasting layer, is portable to other crops and other stress combinations. As climate variability reshapes pest pressure and fertilizer economics tighten, tools that can both identify what is happening in a field today and estimate what is likely to happen in the seasons ahead will become central to food security. The study was supported by the Hainan Provincial Foreign Expert Project on pest monitoring of field corn and the 2115 Talent Development Program of China Agricultural University, and it is published open access, meaning the dataset design and methodology are available to researchers worldwide who want to adapt the approach to their own fields and crops.

Subject of Research: Deep learning-based corn leaf disease identification and environmental risk forecasting in precision agriculture

Article Title: An integrated AI framework for growth stage-aware corn leaf disease identification and environmental impact prediction

Article References: Lu, T., Mhamed, M., He, J., Li, M., Liu, B., Yao, F., Lv, C., & Zhang, Z. (2026). An integrated AI framework for growth stage-aware corn leaf disease identification and environmental impact prediction. Plant Methods. https://doi.org/10.1186/s13007-026-01592-9

Image Credits: AI Generated

DOI: 10.1186/s13007-026-01592-9

Keywords: corn, leaf disease, deep learning, YOLO, precision agriculture, fall armyworm, augmented reality, ARIMA forecasting, image processing, plant pathology, MobileNetV3, nitrogen deficiency

The central problem, the authors contend, is fragmentation. Nanopesticide studies typically report pest mortality or pathogen suppression, nanofertiliser work emphasises nutrient uptake and physiological responses, RNA interference experiments measure gene silencing, and carrier-based formulations are judged by loading capacity, release kinetics, stability or adhesion. Each endpoint is scientifically legitimate in its own context, but the studies differ so widely in dose metrics, exposure routes, target organisms and biological organisation that their results cannot be compared directly. A formulation that kills 90 percent of fall armyworm larvae in a leaf-dip assay tells a farmer almost nothing about whether the same product will protect a maize crop through a rainy season, because the dose that reaches the insect’s gut in the field may be orders of magnitude lower than what the assay delivered.

To resolve this, the review proposes an environmental exposure–response–translation framework that treats formulation design, environmental fate, exposure, biological response and agronomic outcome as a single causal chain rather than separate disciplines. Material attributes such as particle size, surface chemistry, loading and release mechanism are modified after application by sunlight, rainfall, soil pH, organic matter, microbial activity, plant-surface properties and the behaviour of the target pest. These interactions determine whether a formulation stays dispersed, deposits on foliage, survives weathering, releases its active ingredient at the right moment and reaches the intended biological interface. Crucially, the framework distinguishes five dose levels: the nominal dose applied, the dose loaded onto the carrier, the dose released under field conditions, the dose present at the exposure site, and the biologically delivered dose that actually reaches the site of action. The authors argue that biologically delivered dose will predict both pest suppression and non-target risk far more reliably than the nominal concentrations that dominate current reporting.

The framework also classifies nano-enabled agro-inputs along two axes: the mechanism of the active component and the delivery function of the nanoscale system. Five primary classes emerge: intrinsically active nanomaterials such as metal and metal-oxide nanoparticles; small-molecule pesticidal payload systems, including botanical actives like azadirachtin encapsulated in chitosan, mesoporous silica, cyclodextrins or lipid nanoparticles; nucleic-acid payload systems that deliver double-stranded RNA to silence pest genes; biological-agent payload systems that protect and deliver viruses, fungi or bacteria; and nutrient, plant-signal and defence-eliciting systems such as nano-silicon or zinc-based inputs. The classification deliberately separates what produces the biological response from how the response is enabled, so that a chitosan carrier, for example, can be recognised as a pesticide vehicle, an RNA delivery system or a plant-defence stimulant depending on its payload and target rather than its material identity.

The empirical weight of the review comes from paired laboratory-to-field comparisons, drawn heavily from research on fall armyworm, one of the world’s most destructive maize pests and the best-represented target in the nano-enabled crop-protection literature. The reported potency range is staggering: laboratory LC50 values against fall armyworm span from roughly 0.04 milligrams per litre for emamectin benzoate nanoformulations to nearly 10,000 milligrams per litre for silica nanoparticles alone, a difference of about 250,000-fold. Copper oxide nanostructures required around 119 to 135 parts per million, while zinc oxide and silicon dioxide nanoparticles needed 343 and 727 parts per million respectively. The lesson, the authors stress, is that nano-enabled agro-inputs cannot be treated as a single potency class; toxicity depends on the active component, the formulation function, the exposure route and the developmental stage of the pest.

When laboratory potency is compared with practical application rates, a sobering pattern emerges. Some nanoformulations, including DSPE-EB and EMPP/CD@PEG, were applied at approximately 87 and 25 times their laboratory LC50 values, consistent with enormous losses between the tank mix and the delivered dose caused by incomplete deposition, canopy heterogeneity, weathering, degradation and limited ingestion. Not every encapsulation improves matters: polymeric neem formulations performed worse than commercial neem oil at the same azadirachtin concentration, and botanical silver nanoparticle formulations showed weaker responses under field conditions than in the laboratory. The authors interpret these findings as evidence that controlled release or improved loading constitutes a genuine advantage only when it coincides with the pest’s susceptible life stage and maintains adequate exposure under realistic conditions.

Yet the review also documents genuine successes, and they share a common signature: equal or better field control at the same or lower active-ingredient rate. Mesoporous silica carriers known as CLAP@MSNs improved control at essentially the same emamectin benzoate rate as the conventional product. Nano-formulated thiocyclam and chlorantraniliprole retained strong control at one-tenth of the conventional rates. A system combining a pesticide, a star polycation carrier and double-stranded RNA targeting the Nrf2 gene improved field performance while reducing both carrier and dsRNA concentrations relative to laboratory testing. These cases demonstrate delivery, persistence or component-specific optimisation under practical conditions, and the authors argue that they are far more persuasive than potency numbers alone.

For RNA interference technologies, the framework demands an unusually complete evidence chain, because gene knockdown is only an intermediate step between delivery and crop protection. A double-stranded RNA payload must survive gut nucleases, enter cells, escape endosomes, engage the Dicer and Argonaute machinery, suppress the target transcript and its protein, and ultimately produce a phenotype such as reduced feeding, delayed moulting, lowered fecundity or mortality. Substantial knockdown can occur without rapid protein depletion, and protein reduction can fail to produce a phenotype when the gene is redundant or weakly expressed in the exposed tissue. The review therefore calls for time-resolved transcript and protein measurements, matched organism-level phenotypes, and controls including naked nucleic acid, carrier alone and non-target sequences, along with more than one independent RNA sequence where feasible.

Environmental safety receives equally rigorous treatment, framed not as an afterthought but as an integral determinant of efficacy and risk. The same properties that improve delivery can extend residence time, alter mobility and increase contact with non-target organisms. The framework distinguishes environmentally relevant exposure entities, which may be intact particles, aggregates, released active ingredients, dissolved ions or transformation products, and shows that chemically related materials behave very differently: zinc oxide dissolves readily, especially in acidic soils, whereas titanium dioxide tends to persist as intact, soil-associated particles. Biosafety testing is organised by exposure route, from pollinators and natural enemies for foliar sprays to soil microbes, earthworms and aquatic communities for soil, seed and runoff pathways. The authors also address regulation, noting that most jurisdictions handle nano-enabled products through existing pesticide, fertiliser and biostimulant law, and that authorisation of a conventional active ingredient should not automatically extend to a nanoformulation that changes release, persistence, residue behaviour or non-target exposure.

The review closes with a set of five translation-readiness gates and six testable propositions that together turn evaluation into a decision process: delivery adequacy, biological efficacy, comparative advantage over an appropriate conventional product, environmental safety and practical, regulatory readiness. Systems that fail a gate require reformulation, further evidence or rejection rather than optimistic extrapolation. The authors argue that future progress depends less on generating yet more formulations than on testing causal relationships, quantifying biologically delivered dose, aligning release with the target’s exposure window and conducting matched, multi-season field trials that measure agronomic performance, environmental fate and non-target effects concurrently. If adopted, the framework could finally separate nano-enabled technologies that deliver reproducible, efficient crop protection from those whose laboratory sparkle dissolves at the field’s edge.

Subject of Research: An integrated evaluation framework linking environmental fate, exposure and field translation for nano-enabled crop-protection agro-inputs

Article Title: An integrated framework for evaluating nano-enabled agro-inputs: linking environmental fate, exposure and field translation for sustainable crop protection

Article References: Awan, S., Oyege, I., Mwebesa, N., & Kansiime, E. M. (2026). An integrated framework for evaluating nano-enabled agro-inputs: linking environmental fate, exposure and field translation for sustainable crop protection. Journal of Nanoparticle Research, 28(10), Article 248. https://doi.org/10.1007/s11051-026-06747-2

Image Credits: AI Generated

DOI: 10.1007/s11051-026-06747-2

Keywords: nano-enabled agro-inputs, nanopesticides, environmental fate, biologically delivered dose, fall armyworm, crop protection, RNA interference, field translation, sustainable agriculture, environmental exposure, nanocarriers, regulatory readiness

The study, published in the journal Acta Parasitologica, was conducted by Akshay Majare, Nandkishore Lavhe, V. K. Biradar and Tini Pillai of the College of Agriculture in Nagpur, together with colleagues at the ICAR–Central Institute for Cotton Research and the ICAR–Central Potato Research Institute. The researchers set out to answer two questions that matter enormously for anyone designing integrated pest management programmes. First, how lethal are two species of entomopathogenic nematodes, Steinernema siamkayai and Heterorhabditis indica, against third-instar fall armyworm larvae? Second, are these nematodes compatible with two commercially important entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana, and does the answer depend on whether the organisms are applied together or one after the other?

Entomopathogenic nematodes are microscopic roundworms that hunt insect larvae in the soil. Their infective juveniles, the free-living stage used in biocontrol, carry symbiotic bacteria in their guts. When a nematode enters an insect through natural openings such as the mouth, spiracles or anus, it releases these bacteria into the haemocoel, the insect’s open circulatory cavity. The bacteria multiply rapidly, killing the host within days through septicaemia and providing the nematodes with a nutrient-rich environment in which to reproduce. Entomopathogenic fungi attack by a different route: spores germinate on the insect’s cuticle, penetrate the body wall, and proliferate internally, eventually killing the host and sporulating on its corpse. Because the two agents exploit different infection pathways and different ecological niches, scientists have long suspected that combining them could deliver a one-two punch that neither achieves alone.

To test this, the team first measured the inherent virulence of each nematode species under controlled laboratory conditions. Third-instar fall armyworm larvae were exposed to a range of infective juvenile concentrations, from five to one hundred nematodes per larva, and mortality was recorded over ninety-six hours. The results were strikingly asymmetric. Steinernema siamkayai proved consistently and substantially more virulent than Heterorhabditis indica. At doses of thirty to forty infective juveniles per larva, S. siamkayai achieved complete mortality of the test larvae within ninety-six hours, whereas H. indica required the full one hundred juveniles per larva to reach the same endpoint. Probit analysis, a standard statistical technique for quantifying dose-response relationships in toxicology, confirmed the gap: the lethal concentration needed to kill half the larvae, the LC50, was just 5.47 infective juveniles per larva for S. siamkayai, compared with 15.14 for H. indica. The LC90 values told an even starker story, at 14.23 versus 83.52 infective juveniles per larva respectively. In practical terms, the Steinernema species needed roughly one-sixth the dose of its Heterorhabditis counterpart to achieve near-total kill.

With virulence baselines established, the researchers turned to the compatibility question. They paired each nematode with each fungus in three application regimes: simultaneous inoculation, nematode applied first followed by fungus, and fungus applied first followed by nematode. Larval mortality was recorded, and the interactions were classified using co-toxicity factor analysis, a method borrowed from pesticide combination studies that quantifies whether two agents act additively, synergistically or antagonistically when combined. The outcome hinged almost entirely on the nematode species involved. Simultaneous application of any nematode-fungus pair produced additive interactions across the board, meaning the combined mortality matched what would be expected from the sum of the individual effects, with no interference between the agents. The standout combination was S. siamkayai together with Metarhizium anisopliae, which killed 98.55 percent of larvae at ninety-six hours, the highest figure recorded in the laboratory phase of the study.

The picture changed, however, when the agents were applied sequentially. When Heterorhabditis indica was introduced after the fungi had already been applied, the interaction turned antagonistic: the combined mortality fell short of expectations, suggesting that the fungus, by establishing itself in or on the host first, somehow compromised the nematode’s ability to infect or complete its development. The authors did not identify the precise mechanism in this study, but the phenomenon is consistent with competition for the host resource. Both agents ultimately depend on the same larval cadaver for reproduction, and a fungus that has colonised a host first may leave insufficient resources, or an unsuitable internal environment, for the nematode’s symbiotic bacteria to flourish. Notably, Steinernema siamkayai was immune to this sequencing effect, maintaining additive compatibility with both fungi regardless of whether it was applied before or after them. This robustness marks it out as the more dependable partner in a combined biocontrol programme.

To check that the laboratory findings survived contact with more realistic conditions, the team validated the most promising combinations in pot experiments, with mortality and co-toxicity factors assessed at one hundred and twenty hours after treatment. Alone, S. siamkayai caused the highest larval mortality at 80.3 percent, followed by H. indica at 70.5 percent. Among the combined treatments, S. siamkayai plus M. anisopliae again led the field, achieving 71.5 percent mortality, and every nematode-fungus combination tested in pots registered additive interactions by co-toxicity analysis. The somewhat lower figures under pot conditions compared with the laboratory are unsurprising, since soil structure, moisture and other environmental variables inevitably dilute infection efficiency, but the qualitative conclusion held: simultaneous application preserves compatibility, and S. siamkayai is the more forgiving and more lethal of the two nematodes.

The significance of these results extends beyond a single pest. Fall armyworm management currently leans heavily on synthetic insecticides and Bt-transgenic crops, both of which face mounting resistance problems. Field populations of the pest have already shown multiple and cross-resistance to Bt toxins and organophosphates in some regions, and the caterpillar’s polyphagous habits, documented across dozens of host plant species in the Americas, make crop rotation alone an inadequate defence. Microbial biocontrol agents offer a complementary tool that is difficult for pests to circumvent, because the selection pressures they impose differ fundamentally from those of chemical toxins. Moreover, entomopathogenic nematodes and fungi are self-replicating, leave no toxic residues, and are compatible with many other components of integrated pest management, including certain insecticides, as earlier studies on their chemical compatibility have shown.

What this study adds is a practical rule of thumb for deploying such agents together. Compatibility between biocontrol agents is often assumed rather than tested, and the assumption can be costly. Prior research has documented both synergy and antagonism in nematode-fungus combinations against other pests, including black vine weevil, wireworms and scarab grubs, and the mechanisms underlying these interactions, from volatile organic compounds emitted by fungi that influence nematode foraging to direct competition for the host cadaver, remain an active area of investigation. By demonstrating that application sequence is a decisive variable for H. indica but not for S. siamkayai, the Indian team has given practitioners a concrete, testable guideline: if in doubt, apply simultaneously, and if a sequential schedule is unavoidable, choose the nematode species that tolerates it.

The authors identify S. siamkayai, particularly in combination with Metarhizium anisopliae, as a promising microbial strategy for the integrated management of fall armyworm. Field-scale trials will be needed to confirm that the additive interactions observed in the laboratory and in pots translate into meaningful yield protection in farmers’ fields, where UV radiation, desiccation and soil heterogeneity all challenge the survival of both agents. But the core message is already actionable. In the escalating contest between growers and one of the world’s most adaptable crop pests, the details of biological control matter, and something as mundane as the order of two spray applications may be the difference between a partnership that works and one that quietly undermines itself.

Subject of Research: Compatibility and virulence of entomopathogenic nematodes and fungi against the fall armyworm Spodoptera frugiperda

Article Title: Application Sequence Determines the Compatibility and Virulence of Entomopathogenic Nematodes and Entomopathogenic Fungi Against Spodoptera frugiperda

Article References: Majare, A., Lavhe, N., Biradar, V. K., Pillai, T., Deshmukh, V., Banu, G., Fand, B. B., Shah, V., Mhatre, P. H., & Thube, S. (2026). Application Sequence Determines the Compatibility and Virulence of Entomopathogenic Nematodes and Entomopathogenic Fungi Against Spodoptera frugiperda. Acta Parasitologica, 71(5), Article 220. https://doi.org/10.1007/s11686-026-01406-x

Image Credits: AI Generated

DOI: 10.1007/s11686-026-01406-x

Keywords: fall armyworm, Spodoptera frugiperda, entomopathogenic nematodes, entomopathogenic fungi, Steinernema siamkayai, Heterorhabditis indica, Metarhizium anisopliae, Beauveria bassiana, biological control, application sequence, co-toxicity factor, integrated pest management