Genetically modified (GM) cotton expressing Bacillus thuringiensis ( Bt ) toxins is an important tool for managing lepidopteran pests in Brazil; however, its efficacy against Spodoptera frugiperda (J. E. Smith) is reduced because of widespread resistance to Bt maize. Here, we evaluated the performance of Bt cotton and insecticides against Vip3Aa20-resistant, Vip3Aa20-susceptible, and heterozygous strains. The study included two phases: (i) assessment of larval survival and development on Cry1Ac/Cry2Ab2/Vip3Aa20, Cry1Ac/Cry2Ab2, and non- Bt cotton, and (ii) evaluation of the efficacy of thiodicarb and flubendiamide against L2 and L4 larvae surviving on these cotton types. Survival patterns on Bt cotton differed among strains: resistant larvae reached adulthood on both Bt cotton types, albeit with prolonged developmental time; heterozygous larvae survived only on Cry1Ac/Cry2Ab2 cotton; and susceptible larvae died in early instars on both Bt technologies. All strains showed high survival on non- Bt cotton. Thus, Cry1Ac/Cry2Ab2/Vip3Aa20 cotton controlled susceptible and heterozygous larvae completely but allowed substantial survival of resistant larvae, whereas Cry1Ac/Cry2Ab2 cotton was effective mainly against susceptible insects. Thiodicarb caused consistently high mortality of L2 and L4 larvae, including Bt and non- Bt survivors, whereas flubendiamide showed limited lethality. Although combining either type of Bt cotton with thiodicarb improved overall control, it did not fully suppress resistant larvae. These results demonstrate that Vip3Aa20 resistance in S. frugiperda reduces the efficacy of current Bt cotton technologies and underscore the need to integrate Bt cotton with insecticides for the management of this pest. • Vip3Aa20 resistance in Spodoptera frugiperda reduces Bt cotton efficacy. • Cry1Ac/Cry2Ab2/Vip3Aa20 cotton controls susceptible and heterozygous, but not resistant larvae. • Cry1Ac/Cry2Ab2 cotton controls only susceptible larvae. • Thiodicarb controls Vip3Aa20-resistant larvae across instars in Bt and non- Bt cotton. • Flubendiamide shows reduced control of resistant and heterozygous in both cotton types.

Variability in Bacillus thuringiensis (Bt) protein expression, during plant development and between different plant structures, may contribute to the survival of Spodoptera litura (Fabricius) in transgenic Bt crops. This study examined the survival of neonate and second instar S. litura larvae when fed leaf material from field-grown BG3, expressing Cry1Ac, Cry2Ab, and Vip3A, and non-Bt (NBT) cotton plants at different phenological stages (squaring, first flower and/or peak flowering, and cut-out) or different plant structures (leaves, buds, flowers, bolls, and bracts). The effect of alternating diets, where second instar larvae received different combinations of BG3 plant structures and/or NBT leaves was also tested. High mortality levels (>98%) were recorded at day 5 when neonates were fed BG3 plant material from plants of all phenological stages and on all plant structures. Similarly, mortality was high (>99%) when second instar larvae were fed plant material from different BG3 plant structures. However, when larvae were fed an alternating diet of BG3 and NBT leaves from second instar onward, the proportion surviving to adults significantly increased compared with larvae fed exclusively BG3 cotton, irrespective of plant structure combination. These findings indicate that access to a NBT food source, providing intermittent respite from BG3 cotton, can increase larval survival. Further research on NBT host plants, such as weeds or volunteer plants within BG3 fields, is needed to clarify their role in facilitating S. litura survival in BG3 cotton systems.

The pink bollworm (PBW), Pectinophora gossypiella, poses a significant threat to cotton crops, leading to considerable economic damage globally. As the effectiveness of transgenic Bt cotton (BG II) against this pest diminishes, there has been a concerning rise in the use of synthetic insecticides. This study aimed to assess the prevailing levels of insecticide resistance in Indian populations of PBW to commonly recommended insecticides and to investigate the expression of detoxifying enzymes in field populations of PBW exhibiting resistance to insecticides. Ten populations of PBW were collected from major cotton-growing regions of North, Central, and South India. Median lethal concentrations were determined using topical bioassays with five technical-grade insecticides. Most field populations exhibited high resistance to fenvalerate and quinalphos, moderate to high resistance to spinosad and spinetoram, and low to moderate resistance to emamectin benzoate. Overall, populations from Central India exhibited the highest resistance levels, followed by those from North India. Detoxifying enzyme activity was significantly higher in field populations (p < 0.001), with esterases ranging from 84.76 ± 1.91 to 158.92 ± 2.34, glutathione-S-transferase from 15.94 ± 0.96 to 38.89 ± 1.68, and cytochrome P450s from 1.39 ± 0.19 to 5.06 ± 0.22 nmol/min/mg protein, corresponding to increases of 1.02-1.88-fold, 1.09-2.43-fold, and 1.1-3.64-fold, respectively, compared to the susceptible population. These results underscore the need to revise the list of recommended insecticides for PBW management, excluding those to which the pest has developed significant resistance.

Cotton (Gossypium hirsutum L.) is a vital cash crop in India's rainfed Central Zone, facing challenges from low productivity, erratic rainfall, and biotic (sucking pests, diseases) and abiotic (drought) stresses. While Bt cotton varieties with the Bacillus thuringiensis (Bt) gene have reduced bollworm losses, the need persists for high-yielding, stable varieties with broader tolerance. This study evaluates the newly released Bt cotton variety NH 1901 Bt (BG I), bred for rainfed regions of Maharashtra, Gujarat, and Madhya Pradesh. Evaluated over three years (2020-21 to 2022-23) in multi-location trials under the All India Coordinated Research Project (AICRP) on Cotton, NH 1901 Bt achieved a weighted mean seed cotton yield of 1474kg/ha-a 17.32% increase over the Zonal Bt check (Suraj Bt, 1256kg/ha) and 20.71% over the non-Bt check (NH 615, 1221kg/ha). Beyond yield, NH 1901 Bt showed robust tolerance to Bacterial Blight and Alternaria Leaf Spot, plus notable resistance to sucking pests, addressing post-Bt era concerns. It also offers superior fibre quality: Upper Half Mean length of 25.23mm, strength of 25.47g/tex, and Micronaire of 4.17µg/inch, ideal for medium-staple cotton.NH 1901 Bt's consistent performance and broad-spectrum tolerance make it a reliable, high-yielding choice for resource-poor farmers, bolstering sustainable cotton production and the regional economy.

Low Bt toxin concentration in seeds results in low insecticidal efficacy in transgenic Bt cotton. In order to improve the insecticidal efficacy of seeds, two treatments with different amino acid combinations (5 amino acids comprising aspartic acid, glutamic acid, proline, methionine, and arginine; and 21 amino acids) were applied to two Bt cotton cultivars at peak boll stages in 2021 and 2022. The results showed that the amino acid treatments enhanced the seeds’ Bt toxin concentration by 13.5–34.2% compared with the untreated control in a two-year study. However, the difference for the Bt toxin was not significant between the two amino acid treatments. In the seeds, Bt toxin levels correlated positively with amino acid and soluble protein contents, as well as Glutamic-Pyruvic Transaminase (GPT) and Glutamate Oxaloacetate Transaminase (GOT) activities. Conversely, negative correlations were observed between the Bt toxin and the activities of protease and peptidase. Compared with the control, hazard boll rates were also reduced following application of the two amino acid combinations, while no difference was observed between the two amino acid treatments. Because the two treatments performed similarly, these results suggest that applying a simpler combination of five amino acids is an effective and efficient strategy for enhancing the insecticidal efficacy of cotton seeds.

Deciphering the potential of silver-selenium nanocomposites on growth metrics, physiological attributes, and antioxidant profiles in cotton (Gossypium hirsutum L.)

Tobacco thrips ( Frankliniella fusca Hinds) is a major pest of cotton seedlings, leading to substantial economic losses in the United States. Aboveground thrips herbivory has been reported to indirectly reduce cotton root length, yet the relationship between thrips infestation levels and cotton root development remains poorly understood. Bt cotton expressing the Mpp51Aa2 toxin (ThryvOn) can greatly reduce aboveground thrips injury. However, it is unclear whether the root growth responses of ThryvOn cotton differ from those of non-ThryvOn cotton under thrips herbivory. To address these knowledge gaps, greenhouse experiments testing the effects of thrips herbivory on ThryvOn and non-ThryvOn cotton were conducted. Seedlings were infested with 5, 10, or 15 adult female F. fusca , with a non-infested control. After 10 days, several root parameters were measured using a WinRHIZO root-scanner and associated software. Belowground seedling attributes were compared to aboveground seedling growth. We found that root development was impaired as the density of thrips infestation increased. Root traits in non-ThryvOn cotton, including belowground biomass, projected area, root volume, surface area, and total dry mass were reduced when compared to ThryvOn cotton. The root-to-shoot ratio and root mass fraction decreased in non-ThryvOn cotton relative to ThryvOn cotton. Specific root area increased in non-ThryvOn cotton, while root tissue density decreased in ThryvOn cotton. Specific root length did not follow a linear trend and tended to increase at high infestation levels. These findings demonstrate ThryvOn’s ability to tolerate early-season thrips herbivory by maintaining root development, reinforcing that insecticide inputs may be unnecessary. • Early thrips injury reduces cotton root growth and development • Cotton varieties show distinct root economics spectrum strategies • ThryvOn exhibits a conservative resource-use strategy under thrips herbivory • Under thrips herbivory, non-ThryvOn adopts a more acquisitive strategy • Managing early-season insect pests can protect root system development

Pesticide perceptions, practices, and Bt cotton adoption potential among Bangladeshi cotton farmers

Inadvertent use of nitrogenous (N) fertilisers has resulted in low N use efficiency and cotton productivity in high yielding Bt cotton hybrids. Apparently, soil application of prilled urea is associated with substantial N losses posing serious threats to the ecosystem and environment. Consequently, foliar spray of N fertilisers is being practiced in rainfed cotton. However, literature on foliar efficacy of nano urea (12 %) in cotton remains limited. Therefore, a field experiment was conducted with 13 treatment combinations with urea and nano urea as foliar spray one-time at 35 days after sowing (DAS) and two-times at 35 and 55 DAS along with three recommended doses of nitrogen (100 %, 75 %, 50 % recommended dose of nitrogen (RDN)) and compared with foliar spray of urea once at 100 % RDN. The study results revealed few significant (p &lt; 0.05) differences with foliar spray of urea formulations in growth and yield attributes over other treatments. Notably, nano urea two times spray + 100 % RDN significantly increased seed cotton (SC g plant-1) and seed cotton yield (SCY kg ha-1) by 9 % and 6 % respectively, compared to urea spray + 100 % RDN. Similarly, nano urea two times spray + 100 % RDN has significantly increased N concentration and uptake by 7 %, 12 % respectively compared to urea one time spray + 100 % RDN. In contrast, seed index and fiber quality were not significantly influenced by foliar spray of urea formulations. Economic calculations postulated that nano urea two times spray + 100 % RDN recorded the highest benefit to cost (BC), marginal cost benefit ratio (MCBR), with an additional net return of ₹4093 compared to other treatments. Overall, the study highlights the potential of urea formulations as foliar spray at 35 and 55 DAS with 100 % RDN in improving rainfed cotton production under black calcareous soil.

The Gezira Scheme&amp;mdash;one of the world&amp;rsquo;s largest gravity‑fed irrigation systems&amp;mdash;faces chronic water‑timing failures, seasonal credit shortages, and labour constraints that destabilize its official crop rotation and generate large fluctuations in total net return. Although the rotation is fixed on paper, farmers&amp;rsquo; actual rotation has become dynamic, reactive, and constraint‑driven, especially after the 2005 Gezira Act. Using 50 years of data, this study applies a Vector Autoregression (VAR) with an Error Correction Model (ECM) to quantify the dynamic interactions among crop areas (cotton, wheat, sorghum, groundnuts) and total net return. The Error Correction Term captures how quickly the system returns to long‑run equilibrium after water shortages, rainfall variability, price changes, or labour constraints shocks. Results show that the production system is highly sensitive to water timing, with cotton and wheat acting as the main sources of volatility, sorghum functioning as a stabilizing buffer crop, and groundnuts responding opportunistically to liquidity stress. A central structural finding is that only about 25% of the scheme can be irrigated simultaneously due to long‑term deterioration of conveyance capacity, forcing staggered irrigation cycles and chronic timing failures. Small shocks to water, finance, or labour trigger large behavioural adjustments, causing short‑run volatility and long‑run disequilibrium. Shifting irrigation from push to pull system at the minor and field canal levels&amp;mdash;while maintaining the 25% simultaneous‑irrigation constraint&amp;mdash;creates a demand‑driven water delivery regime that dramatically reduces water stress and timing failures, stabilizes crop choices, and improves both short‑run and long‑run system performance. This intervention with digital transformation aligns directly with VAR-ECM findings showing water as the primary driver of volatility and offers a practical, resilience‑engineering pathway to restore stability and predictability in the Gezira Scheme. The study proposes a resilience‑engineering intervention framework&amp;mdash;including downstream pull‑system irrigation at minor and field canal levels, Bt cotton adoption, reducing cotton area to save water, predictable seasonal finance, and mechanization&amp;mdash;to restore system stability and improve water use efficiency. VAR-ECM stability tests confirm that these interventions directly address the structural drivers of volatility. This study provides the first dynamic econometric assessment of the Gezira Scheme&amp;rsquo;s production system, quantifies crop‑specific roles in system sensitivity and stability, identifies water‑timing constraints as the dominant behavioural driver of rotation deviations. Significant contribution of the study is using econometric model for analyzing short‑run adjustments and long‑run equilibrium relationships in Gezira production system and introduces a novel integration of resilience‑engineering interventions within a VAR-ECM framework to guide sustainable transformation of large‑scale irrigation systems.

A field experiment was conducted during the two consecutive kharif seasons of 2019 and 2020 at Agronomy Instructional Farm, Chimanbhai Patel College of Agriculture, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, to study the yield maximization of Bt cotton through agro-techniques in loamy sand. The experiment consisted of four factors viz; spacing, topping, intercropping and sowing time with two levels in each treatment. The results of pooled data of 2 years revealed that Bt cotton sown at spacing of 60 cm × 45 cm recorded significantly higher plant height, crop growth rate as well as seed cotton and stalk yields, seed cotton equivalent yield, oil yield while significantly higher number of sympodial branches per plant, relative growth rate, number of brusted bolls per plant, weight of seed cotton per boll and seed cotton yield per plant with wider spacing of 120 cm × 60 cm. Topping carried out at 75 DAS remarkably improved growth and yield attributes, seed cotton and stalk yields, seed cotton equivalent yield, oil yield. All growth and yield attributes as well as seed cotton yield were recorded significantly higher without intercrop in Bt cotton. Though intercropping of greengram (additive series) in Bt cotton produced significantly higher seed cotton equivalent yield than no intercropping in pooled mean. Advance sowing of Bt. cotton on last week of May significantly produced significantly higher seed cotton yield and seed cotton equivalent S1T2I2D1 [Advance sowing (Last week of May) at plant spacing of 60 cm × 45 cm along with topping at 75 DAS and intercropping with greengram] gave significantly higher seed cotton equivalent yield as well as net returns and B: C ratio of Bt. cotton.

Bt cotton (Gossypium hirsutum) was introduced in India in the form of hybrids by the private seed industry in 2002. Since hybrid seeds were expensive and its cultivation is input intensive, cotton breeders from the public sector R&amp;D institutes released Bt cotton varieties in 2020 suitable for planting under low input situations. For this first time, this study evaluated the productivity potential of first four Bt varieties viz. ICAR-CICR PKV081-Bt, ICAR-CICR Suraj Bt, ICAR-CICR Rajat Bt, and ICAR-CICR GJHV 374 Bt in a split plot design under rainfed conditions on a Vertisol, sub-group Typic Haplusterts, under four plant densities viz.,0.37 lakh, 0.55 lakh, 0.74 lakh and 1.1 lakh plants/ha. The results indicated that there were significant differences among varieties and plant densities with respect to seed cotton yield, lint yield, boll weight, days to first open flower and earliness index. ICAR-CICR PKV081-Bt was the most productive variety, yielding 2639 kg/ha at 0.37 lakh plants/ha. The interaction (variety × plant density) was significant for seed cotton yield, lint yield and boll density. For varieties, PKV 081 Bt and Rajat Bt, 0.37 lakh plants/ha was optimum whereas for Suraj Bt and GJHV 374 Bt, 0.74 lakh plant/ha was optimum plant density. At densities of 0.74 and 1.1 lakh plant/ha, the plant height increased and the maturity was delayed. The study highlights the importance of selecting appropriate Bt varieties and optimizing planting density to increase the productivity of rained cotton on Vertisols of Central India.

Apolygus lucorum, a phytozoophagous mirid bug, plays an important role in the species interactions within fruit tree and cotton ecosystems. Previous research has mainly focused on the phytophagous damage that it causes to crops, while its role as a predator of arthropods remains poorly understood. In this study, we systematically investigated the functional responses of A. lucorum to three crop pests: eggs of Helicoverpa armigera, nymphs of Aphis gossypii, and nymphs of Bemisia tabaci. The results show that the predatory behavior of A. lucorum towards all three prey species followed a Holling type II functional response model. Predatory performance varied significantly depending on prey species, developmental stage, and sex of the mirid. The theoretical maximum predation rate was highest for A. gossypii (833.33 individuals/day) and lowest for B. tabaci nymphs. Adult mirids and older nymphs (4th instar) exhibited higher predation rates than younger nymphs. Field-collected A. lucorum from Bt cotton fields were analyzed using molecular diagnostics, and the result confirmed natural predation on A. gossypii, which was consistent with observed pest occurrence patterns in the field. Overall, this study clarifies the prey selectivity and stage-dependent predatory strategies of A. lucorum, providing insights into its trophic flexibility as a facultative predator. These findings contribute to a more comprehensive understanding of its ecological role in agricultural ecosystems, but do not support its use as a biological control agent given its predominantly phytophagous nature and documented pest status.

Effect of Bt cotton based cropping system and nutrient management to rabi crops on growth and yield attributes of Bt cotton

The emergence of modern biotechnology has been a strong instrument to handling significant problems in the agricultural sector especially in matters of food shortage, dwindling soil fertility, climate change, and the growing population in the world. The conventional farming methods are usually inadequate to ensure that there is food to satisfy the increasing demand of food and at the same time keeping the environment sustainable. In this respect, the current biotechnological methods offer innovative ways of improving the crop productivity, nutritional value, and breeding stress-resistant plant types. Genetic engineering, plant tissue culture, molecular markers, and genome editing are some of the techniques that have greatly been used in crop improvement programs. Through genetic modification, crops are developed with some desirable qualities such as resistance to pests, diseases, drought and salinity tolerant, and with improved nutritional value. As an example, genetically modified crops like Bt cotton and bio fortified crops have shown to yield better and less dependency on chemical pesticides. On a similar note, the methods of plant tissue culture enable the high-yield and disease free plants to proliferate within a short period of time which enables the production of large scale agriculture. Molecular breeding and marker-assisted breeding breeders continue to speed up the elimination of bad things, selecting good things much more readily as compared to traditional breeding approaches. Biotechnology is also crucial to sustainable farming practices, as it encourages the adoption of biofertilizers, bio pesticides and microbial technologies which minimize pollution of the environment and ensure the health of the soil. Such sustainable methods of production mean environmental-friendly production of crops with low impacts of excessive use of chemicals. Moreover, the current genome editing technology like CRISPR has provided novel opportunities of more specific genetic manipulation, where legislation of climate-resistant crops can be developed to adapt to the evolving environmental factors. In general, contemporary biotechnology promises to provide effective solutions to enhance food systems in the world by enhancing the productivity of agriculture, crop resistance, and sustainable agriculture. Further studies, responsible use and proper legal frameworks are required to make sure that biotechnological innovations become useful in guaranteeing global food security and sustainable agricultural development.

Soil health plays a pivotal role in sustaining agricultural productivity, particularly in the context of genetically modified crops such as Bt cotton. This study assesses soil fertility and physical parameters under irrigated and non-irrigated Bt cotton cultivation systems in North Maharashtra, India, spanning Jalgaon, Dhule, and Nandurbar districts. Using 210 soil samples collected over six years (2017-2023), key indicators including pH, electrical conductivity (EC), organic carbon (OC), and calcium carbonate (CaCO3) were analyzed. Results reveal minimal variations between irrigated and non-irrigated soils but indicate low organic carbon and slightly alkaline soil conditions across both systems. The current research work emphasizes the need and important for integrated organic nutrient management to restore soil fertility under intensive Bt cotton cultivation practices

A twist in India's farming future came with Bt Cotton boosting exports fast. Yet hesitation followed when new crops like Bt Brinjal faced roadblocks despite years of study. One reason sits buried in outdated rules drafted back in 1989 under broad environmental laws. Tensions flare where patent rights meet traditional seed-saving habits protected by separate farm acts. Courts now step in often, filling gaps left by slow-moving agencies. Landmark rulings have shifted how risk assessments unfold across states. Global promises made through treaties nudge policy but clash with local resistance. Progress stalls not from lack of science, but fractured oversight without clear authority. A single dedicated body might cut delays, some argue, though debate drags on.

India’s cotton supply chain is undergoing a period of acute stress, marked by falling productivity, declining acreage, rising imports, and weakening farm–firm linkages. This article examines the recent reversal of the 11% import duty on raw cotton, announced in the aftermath of the punitive tariffs imposed by the Trump administration, against the backdrop of deeper structural changes in Indian cotton production, trade, and global textile markets. While technological adoption, particularly Bt cotton, drove significant gains in output during the 2000s, productivity of Indian cotton has stagnated over the past decade amid pest resistance, rising input costs, and limited investments into public research and extension. These domestic constraints, combined with adverse international trade dynamics, loss of export competitiveness, and a global shift towards man-made fibres, have eroded India’s price parity in cotton and yarn markets. The resulting supply constraints have intensified pressures on both farmers and textile enterprises. The article argues that a sustainable revival of India’s cotton sector hinges on addressing productivity and profitability gaps through renewed public investment in research, technology, and cost-reducing farm policies, thereby re-establishing resilient farm-to-firm linkages within the cotton value chain.

The comparative biology of pink bollworm (PBW) on Bt cotton bolls and fruit pods of malvaceous plants viz., Abutilon indicum, Abutilon hirtum and Abelmoschous ficulneus was investigated under controlled conditions. The incubation time of PBW eggs from different hosts ranged from 2.0 to 4.5 days, which was not differ significantly among treatments. The mean larval duration of all four instars as well as average larval duration of pink bollworm reared on Bt cotton was more as compared to the larvae reared on A. indicum, A. hirtum and A. ficulneus. The average male and female pupal period were longer on Bt cotton. Both adult male and female from Bt cotton lived longer as compared to adults from A. indicum, A. hirtum and A. ficulneus. The weight of the different life stages of the pink bollworm was also more significant when reared on Bt cotton. Similarly, morphometric parameters, including larval body length and width, as well as pupal size and adult body dimensions (including wing expanse), were significantly greater in PBW reared on Bt cotton than on other hosts. Larvae feeding on Bt cotton undergo physiological stress that delays development but allows extended feeding and compensatory growth, resulting in higher weight and longevity. Thus, Bt cotton induces delayed development in Bt tolerant populations, while non-cotton malvaceous hosts support faster but nutritionally inferior development. Thus, the results clearly indicate that the pink bollworm completes its life cycle on malvaceous hosts and this also might be a reason for the off seasonal survival of pink bollworm in cotton growing regions. This study could have implications for crop management strategies for controlling the pink bollworm, that can cause significant damage to cotton crops.

The present investigation entitled &ldquo;Influence of Canopy Management on Physiological Characteristics and Yield Performance of Bt Cotton (Gossypium hirsutum L.) in High-Density Planting Systems&rdquo; was conducted during kharif 2022 and 2023 at the All India Coordinated Cotton Improvement Project, MPKV, Rahuri, Maharashtra. The experiment was laid out in a split plot design with 48 experimental plots, comprising different spacing (60 &times; 30 cm, 90 &times; 30 cm, 120 &times; 30 cm and 120 &times; 60 cm) along with canopy management practices. The results indicated that wider spacing improved leaf thickness, chlorophyll index and photosynthetic rate, while closer spacing recorded a higher leaf area index due to greater plant density. Among the treatments, pruning at 40 DAS and topping at 70 DAS showed superior physiological performance and plant growth. The highest seed cotton yield was obtained with 90 &times; 30 cm spacing and the interaction S2T1 (90 &times; 30 cm spacing with pruning at 40 DAS and topping at 70 DAS) recorded the maximum yield. Overall, appropriate spacing combined with effective canopy management significantly enhanced the physiological traits and yield of Bt cotton under high-density planting systems.