Non-chemical Methods Research Articles

How Does Herbicide Resistance Change Farmer’s Weed Management Decisions? Evidence from the Roundup Ready Experiment

Adoption of diverse weed management practices is viewed as essential for slowing the spread of herbicide-resistant (HR) weeds. Yet, adoption of diverse tactics has remained low, while there has been explosive growth of resistant weeds. This study analyzes U.S.-farm-level data to identify factors affecting adoption of diverse weed management practices. This study uses directed acyclic graphs (DAGs) to consider how practice adoption is influenced by different causal pathways between farmer and farm characteristics and farmer awareness of and concern over HR weeds. This study then uses multiple regression analysis to estimate the direct and indirect pathways that influence practice adoption. Respondents relied more heavily on herbicide-based weed control methods than on mechanical or cultural methods. Concern over herbicide resistance increased the number of practices farmers adopted and the percentage of acres where farmers implemented these practices. Practice adoption was negatively associated with increasing levels of farmer risk aversion. Technological optimism—belief that new herbicides would soon be developed to counter HR weeds—discouraged diverse herbicide use practices that combat resistance, but encouraged use of some non-chemical weed control methods. Perceived weed dispersal externalities (from weed mobility) led to more diverse weed management, running counter to hypotheses that greater mobility reduces incentives for individual resistance management.

Skutterudites as sustainable thermoelectric material- A critical review

In this article, we comprehensively reviewed the thermoelectric proper- ties of skutterudites-based materials. We discussed the various synthesis methods like non-chemical and chemical methods for the synthesis of the skutterudites materials for thermoelectric applications. In particular, this review articles also consolidates the information on how the filler plays a crucial role in improving the thermoelectric performance of the skutterudites materials. In addition, this review also concentrates on diverse fabrication methods employed in the production of skutterudites to optimize their thermoelectric performance. It also elucidates the efficiency of devices based on skutterudite materials and discusses the applications of thermoelectric devices.

Forecasting Western Corn Rootworm (Diabrotica virgifera virgifera LeConte) Density and Non-Chemical Control of Larvae: A Practical Review

The western corn rootworm (WCR) (Diabrotica virgifera virgifera LeConte; Chrysomelidae) is one of the most significant maize pests in Europe, with farmers spending a substantial amount (approximately 140 EUR) on its control. In the context of climate change, WCRs could pose an even greater threat to EU maize production, particularly as the European Union continues to withdraw an increasing number of effective yet environmentally harmful active agents. Biological control methods have now emerged to the forefront in creating sustainable agriculture. In this review, we carried out an extensive literature analysis on methods for forecasting WCRs and evaluated the practical applicability of the latest non-chemical control methods targeting its larvae. Effective forecasting is essential for successful pest management, enabling informed planning and the selection of the most suitable control methods. Several traditional predicting techniques remain in use today, but recent advancements have introduced modern electronic forecasting units combined with sensor-equipped pheromone and colour traps, as well as thermal sum calculations. Research has demonstrated that crop rotation is one of the most effective methods for controlling WCR larvae. Biological agents, such as entomopathogenic fungi (Beauveria bossiana and Mettarrhyzum anasoplia), entomopathogenic nematodes (Heterorhabditis bacteriophora), and botanical insecticides such as azadirachtin can significantly reduce larval populations and root damage, thereby maintaining infestation levels below the economic threshold. Genetically modified maize plants that produce specific toxins, along with conventional breeding efforts to increase root system regeneration, are also promising tools for the sustainable management of this pest. This review summarizes the solutions for prediction of western corn rootworm infestations and non-chemical control of its larvae. Accurate forecasting methods provide a clear picture of infestation levels in a given area, enabling precisely targeted control measures. In all cases, the control should be directed primarily against the larvae, thereby reducing root damage and reducing the size of the emerging imago population. This review demonstrates that biological control methods targeting larvae can be as effective as pesticides, supporting sustainable pest management.

Effects of weed management on soil metagenomic composition in cultivated chickpea fields

Abstract Non-chemical methods, including mechanical and manual weed management are important for improving crop yields and preserving soil microbial diversity. In Tunisia, chickpea cultivation uses a combination of these methods to suppress weeds. This study aimed to evaluate the impact of weeding practices on chickpea (Cicer arietinum L. cultivar REBHA) yield and soil microbial diversity. Field experiments were conducted at the Technical Center for Biological Agriculture in Essaida, Tunisia, using six plots with manual and no weeding treatments. Chickpea yield was measured, and soil samples were collected for metagenomic analysis. Floristic surveys identified 13 weed species, with Chenopodium album L., Rumex acetosa L., and Urtica dioica L. being the most dominant. Seed yield ranged from 23.2 to 26.2 qls/ha in non-weeded plots and from 25.1 to 30.1 qls/ha in weeded plots, showing an increase in yield (11.75%) with manual weeding.
Soil metagenomics revealed changes in bacterial community composition between the two treatments. The dominant phylum was Pseudomonadota, whose relative abundance increased from 24.88% in non-weeded plots to 34.76% in weeded plots. Alpha diversity indices showed lower species richness and diversity in weeded soils, with 62000 OTUs in weeded plots compared to 43202 OTUs in non-weeded plots. Betaproteobacteria and Alphaproteobacteria exhibited higher OTU counts in weeded soils. The Simpson diversity index was lower in non-weeded soils (0.025) than in weeded soils (0.075), indicating a more irregular microbial distribution in non-weeded plots. Thus, manual weeding improved chickpea yield and altered the soil bacterial community, increasing diversity in key microbial taxa. This study highlights the complex interaction between weed management practices and soil microbial ecosystems, which may influence crop productivity.

Selection and adaptation to weed management methods: implications for non-chemical and integrated weed management approaches.

Herbicide-resistant weeds are a growing global concern, threatening food security. Non-chemical weed management approaches are becoming increasingly important. Furthermore, the adoption of non-conventional agricultural practices is on the rise, with regenerative farming practices aimed at rebuilding soil organic matter, restoring biodiversity, and reducing chemical use gaining traction. Consequently, non-chemical weed management methods are seen as essential solutions. However, excessive reliance on these methods may inadvertently lead to weed selection and adaptation, reducing their effectiveness. Here, we explore the mechanisms driving changes in efficacy due to selectivity and adaptation to non-chemical weed management practices. Additionally, we discuss potential integrated weed management (IWM) strategies that combine chemical and non-chemical methods to mitigate the risks of weed adaptation. This study highlights the role of evolutionary processes in shaping weed adaptation to non-chemical weed management methods and underscores the need to understand these processes to develop IWM approaches that remain effective over time. Monitoring phenological shifts and adaptations in the field should be a key component of decision support systems, tailored to the unique conditions of each site. Furthermore, a deeper understanding of weed adaptation mechanisms can enhance the efficacy of IWM strategies and help delay the inevitable adaptation to these control methods. © 2024 Society of Chemical Industry.

Resistance Management for Cancer: Lessons from Farmers.

One of the main reasons we have not been able to cure cancers is that treatments select for drug-resistant cells. Pest managers face similar challenges with pesticides selecting for pesticide-resistant insects, resulting in similar mechanisms of resistance. Pest managers have developed ten principles that could be translated to controlling cancers: (1) prevent onset, (2) monitor continuously, (3) identify thresholds below which there will be no intervention, (4) change interventions in response to burden, (5) preferentially select non-chemical control methods, (6) use target-specific drugs, (7) use the lowest effective dose, (8) reduce cross-resistance, (9) evaluate success based on long-term management, and (10) forecast growth and response. These principles are general to all cancers and cancer drugs and so could be employed broadly to improve oncology. Here, we review the parallel difficulties in controlling drug resistance in pests and cancer cells. We show how the principles of resistance management in pests might be applied to cancer. Integrated pest management inspired the development of adaptive therapy in oncology to increase progression-free survival and quality of life in patients with cancers where cures are unlikely. These pest management principles have the potential to inform clinical trial design.

Relative Benefits of Aqueous Extract of Sorghum Residues with Herbicide on Weed Control and Yield of Wheat Varieties

Reducing herbicide use in agriculture is key for sustainability, addressing costs, environmental issues, and resistance problems. Using non-chemical methods like allelopathy in weed management offers a viable alternative. In this phenomenon, a field study was carried out at the Agronomy Field Laboratory (AFL) of Bangladesh Agricultural University (BAU), Mymensingh, from November 2021 to March 2022, to assess the phytotoxic effects of herbicides combined with aqueous extract of sorghum (AES) on weed management and yield of wheat. This study used three wheat varieties viz. BARI Gom (wheat)-32, BARI Gom-33, and BWMRI Gom-1 and six treatment levels such as, no weeding, recommended dose of herbicide (RDH), 90% RDH + AES (1:20 w/v), 80% RDH + AES (1:20), 70% RDH + AES (1:20), and 60% RDH + AES (1:20). The experiment followed a randomized complete block design (RCBD) with three replications. The RDH with AES and wheat variety significantly influenced weed population (WP) and dry weight (DW) of weeds. BARI Gom-32 produced the highest grain yield (GY) and other yield-contributing characteristics. The best results, including the highest numbers of tillers (NET) hill-1 (6.47), spike length (SL) (15.10 cm), number of spikelet spike-1 (NSS) (19.38), 1000-grain weight (TGW) (57.67g), GY (5.10 t ha-1), and straw yield (SY) (7.07 t ha-1) and harvest index (HI) (41.95%) were observed in plots treated with the RDH and the BARI Gom-32 variety, followed closely by those receiving 90% RDH + AES (1:20). The results demonstrate that varying concentrations of AES crop residue can effectively suppress weed growth and enhance wheat yield, suggesting that sorghum residues might be utilized to manage weeds effectively and sustainably while boosting wheat production. The study supports the potential of AES crop residue as an effective means to control weeds and significantly improve wheat yields. J Bangladesh Agril Univ 22(3): 326-334, 2024

Reduced anthelmintic use on 13 New Zealand sheep farms: farmer motivations and practical implementation

ABSTRACT Aims: To describe the personal drivers, sources of information and gastro-intestinal parasite control methods used by a group of New Zealand sheep farmers identified as low users of anthelmintic (AHC), and their perception of the efficacy and impacts of this approach. Methods: A convenience sample of 13 sheep farmers farming with a policy of reduced AHC use (no pre-determined routine treatments of ewes >19 months old and/or lambs not routinely treated at pre-determined intervals from weaning through to late autumn) were identified. Semi-structured interviews were conducted regarding their farming philosophy, motivations for reducing AHC use, perceptions of the impacts of farming with reduced AHC use, and parasite control practices. Semi-quantitative data were analysed using descriptive statistics for demographic data and categorising participants’ use of AHC and non-chemical control methods. Qualitative data regarding participants’ motivations, approaches and rationale were analysed by systematic analysis of the transcripts and distillation of key concepts. Results: Participants had been operating with reduced AHC use for 3 to ≥20 years. Key motivators for reducing AHC use were a diagnosis of anthelmintic resistance (AR) or concerns about AR developing. Parasite management information came from a wide range of sources. All respondents expressed overall positive views regarding the impacts of reduced AHC use but detailed information was not available. All identified that regular monitoring, based primarily on subjective animal and non-animal factors was important for their parasite control strategy. Most used faecal egg counts (FEC), often in an ad hoc manner. Five never treated adult ewes, two routinely treated ewes prior to lambing with short-acting AHC and the remainder occasionally treated a small number in low body condition. Four routinely treated some or all lambs at 28–30-day intervals from weaning to late autumn while the remainder based their treatment decisions for lambs on monitored information. All placed heavy emphasis on feeding sheep well, ensuring high post-grazing residuals, and cross-grazing. Conclusions: AR was a key motivator for participants to reduce AHC use, and a range of information sources and decision-making processes were used. Key parasite management practices were monitoring, primarily using subjective assessments, emphasis on feeding stock well and cross-grazing. Clinical relevance: The rising prevalence of AR will likely result in increasing the motivation for sheep farmers to reduce their AHC use. Veterinarians will play a key role in providing advice and assistance to facilitate changes in parasite management.

Motivation and opportunity may drive Tunisian farmers to reduce chemical pesticides in horticulture

This study investigates the sociopsychological factors influencing Tunisian farmers’ adoption of sustainable pest management techniques by employing the motivation-opportunity-ability framework and using partial least squares structural equation modelling. It is the first empirical study to test this framework in predicting farmers’ readiness to reduce pesticide usage in agriculture, distinguishing between intrinsic and extrinsic motivations. The findings reveal that both intrinsic and extrinsic motivations significantly impact farmers’ readiness to reduce pesticide use. Particularly, extrinsic motivations, such as peer influence and prevailing practices within the community, play a crucial role, highlighting the importance of social dynamics in sustainable agricultural decisions. Additionally, opportunities to adopt non-chemical pest control methods, enhanced by access to information and technology, positively influence farmers’ intentions to minimize pesticide use. These results suggest that enhancing farmers’ motivation through targeted educational programs and fostering opportunities via supportive policy environments are key strategies to promoting sustainable pest management practices in the region.

Combined Application of Herbicide and Aqueous Extract of Sorghum and Mustard Crop Residue Enhance Weed Management and Yield of Wheat

The rising costs in agriculture and growing public concern over herbicide use have emphasized the need for non-chemical weed control methods. To evaluate the impact of aqueous extracts from sorghum and mustard crop residues on weed control and wheat crop performance, an experiment was conducted at the Agronomy Field Laboratory (AFL) of Bangladesh Agricultural University (BAU), Mymensingh, from November, 2021, to March 2022. The study involved three wheat varieties (BARI Gom-32, BARI Gom-33, and BWMRI Gom-1) and six treatment levels: no weeding, the recommended dose of herbicide (RDH), 80% RDH + aqueous extract of mustard + sorghum (AEMS) (1:20 ratio w/v), 70% RDH + AEMS (1:20), 60% RDH + AEMS (1:20), and 50% RDH + AEMS (1:20). The experiment was designed using a randomized complete block design with three replications. Results demonstrated that the aqueous extracts significantly reduced weed population (WP) and dry weight (DW) of weeds. Among the wheat varieties, BARI Gom-32 achieved the highest grain yield (GY) (3.62 t ha-1) and other yield-contributing traits. The highest numbers of effective tillers (NET) per hill (4.56), numbers of grains per spike (NGS) (34.57), 1000 grain weight (TGW) (57.81 g), GY (4.09 t ha-1), straw yield (SY) (6.05 t ha-1), and biological yield (BY) (10.14 t ha-1) were observed in the RDH treatment, followed by the combined application of 80% RDH and AEMS crop residue (1:20). These findings suggest that AEMS crop residue extracts could be an effective source for suppressing weed population and enhancing yield.

Effects of Melia azedarach extract on demographic and biochemical characteristics of the cabbage aphid, Brevicoryne brassicae

The cabbage aphid, Brevicoryne brassicae L. (Aphididae: Hemiptera) a destructive aphid, is native to Europe and is now found in many other parts of the world. Currently, one of the main problems of Iranian cabbage growers is the significant damage caused by this pest. Also, due to the fresh eating of cabbage, it is necessary to use non-chemical methods to control the pests. Our bioassay tests showed that Melia azedarach L. (Meliaceae) fruit extract showed high toxicity to cabbage aphid. In this study, sublethal effects of M. azedarach extract was investigated on some demographic and biochemical properties of B. brassicae. The results showed that the sublethal concentrations (LC10 and LC20) and LC50 values were 0.68, 1.16, and 3.42 μg/ml, respectively. Compared to the control, sublethal concentrations of insecticide significantly decreased the gross reproductive rate (GRR), net reproductive rate (R0), intrinsic rate of increase (rm), finite rate of increase (λ), intrinsic rate of birth (b), intrinsic rate of death (d), weekly growth rate (rw), reproductive rate and adult longevity of the pest. Meanwhile, the mean generation time (T) and population doubling time (DT) of this aphid increased significantly. Additionally, sublethal doses of insecticide reduced the energy reserves of the pest such as carbohydrate, protein and lipid content compared to the controls. In addition to modify the pH, this extract also changed the distribution and concentration of sodium and potassium ions in haemolymph. Therefore, sublethal concentrations of M. Azedarach fruit extract can be used in the management program of B. brassicae.

Controlling of beet armyworm (Spodoptera exigua) in shallot by non-chemical methods

Controlling of beet armyworm (<i>Spodoptera exigua</i>) in shallot by non-chemical methods

On-farm harvest timing effects on alfalfa weevil across the Intermountain West region of the United States.

Alfalfa (Medicago sativa L.) is an economically important commodity in the Intermountain Western United States. A major concern for alfalfa producers in this region is the alfalfa weevil (Hypera postica Gyllenhal). Insecticide resistance development coupled with regulatory changes in pesticide use has resulted in renewed interest by producers in non-chemical control methods such as cultural control. One such cultural control method is early harvest, which consists of producers timing their harvests early in the season to decrease alfalfa weevil damage. This method is thought to be effective by exposing weevil larvae to adverse conditions before significant damage occurs. Still, early harvest can be difficult to employ because recommendations are often vague. To better understand how early harvest impacts both alfalfa weevils and their natural enemies and how producers are using this method across the Intermountain Western United States, we conducted a study in alfalfa production fields in Colorado, Montana, and Wyoming over three growing seasons. We determined that the timing of the initial alfalfa harvest spanned more than 1 month across fields, and alfalfa plant stage at harvest ranged from late vegetative to early bloom. Harvest was more impactful on reducing alfalfa weevil densities the earlier it was implemented. Removing windrows in a timely manner is likely useful to further decrease alfalfa weevil densities. Harvest timing was not associated with parasitism rates of alfalfa weevil, but higher parasitism rates were associated with lower post-harvest alfalfa weevil densities. This work has increased our understanding of early harvest in an on-farm setting and to improve recommendations for producers across the Intermountain Western United States.

Facilitators and barriers to integrated malaria prevention in Wakiso district, Uganda: A photovoice study.

Malaria continues to cause significant morbidity and mortality globally, particularly in sub-Saharan Africa. Appropriate combinations of non-chemical and chemical methods of malaria vector control in the context of integrated vector management have been recommended by the World Health Organization. The aim of the study was to explore facilitators and barriers to using integrated malaria prevention in Wakiso district, Uganda. This qualitative study employed photovoice among 20 community members in Kasanje Town Council, Wakiso District. The photos taken by participants for 5 months using smartphones were discussed during monthly meetings with the researchers. The discussions were audio-recorded, and resulting data analysed using thematic analysis with the support of NVivo (2020) QSR International. Findings indicated that various conventional and non-conventional measures were being used for preventing malaria such as: insecticide treated nets; clearing overgrown vegetation; draining stagnant water; mosquito coils; smouldering of cow dung; spraying insecticides; plant repellents near houses; eating of prophylactic herbs; as well as closing doors and windows on houses early in the evening. Facilitators supporting the use of several malaria prevention methods holistically included: low cost and accessibility of some methods such as slashing overgrown vegetation; and support provided for certain methods such as receiving free mosquito nets from the government. Barriers to using several malaria prevention methods holistically included: inadequate knowledge of some methods such as housing improvement; allergic reactions to chemical-based methods such as insecticide treated nets; unaffordability of some methods such as insecticide sprays; and inaccessibility of certain methods such as body repellents. These barriers to integrated malaria prevention need to be addressed to achieve greater impact from the combination of methods in endemic communities.

Nonchemical Aquatic Weed Control Methods: Exploring the Efficacy of UV-C Radiation as a Novel Weed Control Tool.

Aquatic weeds, including invasive species, are a worldwide problem. The presence of aquatic weeds poses several critical issues, such as hindering the continuous flow of water in irrigation channels and preventing the proper distribution of adequate water quantities. Therefore, effective control measures are vital for agriculture and numerous downstream industries. Numerous methods for controlling aquatic weeds have emerged over time, with herbicide application being a widely used established method of weed management, although it imposes significant environmental risks. Therefore, it is important to explore nonchemical alternative methods to control existing and emerging aquatic weeds, potentially posing fewer environmental hazards compared with conventional chemical methods. In this review, we focus on nonchemical methods, encompassing mechanical, physical, biological, and other alternative approaches. We primarily evaluated the different nonchemical control methods discussed in this review based on two main criteria: (1) efficiency in alleviating aquatic weed problems in location-specified scenarios and (2) impacts on the environment, as well as potential health and safety risks. We compared the nonchemical treatments with the UV-C-radiation-mediated aquatic weed control method, which is considered a potential novel technique. Since there is limited published literature available on the application of UV-C radiation used exclusively for aquatic weed control, our review is based on previous reports of UV-C radiation used to successfully control terrestrial weeds and algal populations. In order to compare the mechanisms involved with nonchemical weed control methods, we reviewed respective pathways leading to plant cell death, plant growth inhibition, and diminishing reemergence to justify the potential use of UV-C treatment in aquatic habitats as a viable novel source for aquatic weed control.

Control of citrus nematode Tylenchulus semipenetrans (Tylenchida: Tylenchulidae) using plant-based products under in vitro and in vivo conditions

The citrus nematode (Tylenchulus semipentrans) is one of the most important parasitic nematodes affecting citrus trees, causing gradual decline and reduced yield. Potential risks, high costs and environmental consequences of chemical compounds have led researchers to explore non-chemical methods such as using plant-based products for nematode management. The present study was conducted to control citrus nematodes using essential oil and water extract of Artemisia annua and methanolic extract of Melia azederach under laboratory and greenhouse conditions. In vitro bioassays were carried out, and the effects on toxicity, mortality, and egg hatching were assessed. The highest in vitro nematistatic activity was recorded for 250 ppm of A. annua essential oil and 500 ppm of M. azederach methanol extract by 100% paralysis of nematodes after 48 h. Furthermore, the highest nematicidal activity of A. annua essential oil, aqueous extract and methanolic extract of M. azederach was recorded to be about 60−100%, 40−87% and 38−100%, respectively. Among all concentrations of M. azederach methanolic extract and high concentrations of A. annua essential oil and aqueous extract, the repellents and motility inhibitors for nematodes were found. The results of egg hatching showed that essential oil of A. annua at a concentration of 250 ppm had the greatest reduction of egg hatching. In a greenhouse experiment, all the treatments were found to be significantly effective against the citrus nematode population in soil and roots compared to the control. Maximum reduction was observed in 500 ppm of methanolic extract of Melia azederach. Growth parameters (plant height, fresh and dry shoot and root weight) increased compared to the control when treatments were applied. Based on the results, plants such as A. annua and M. azedarach are considered to be promising control agents for citrus nematodes. The results indicate that products derived from these plants may be potential candidates for formulating new nematicides suitable for sustainable nematode management, although field trials are still needed to demonstrate their effectiveness for commercial use.

Efficacy of pesticides against Nesidiocoris tenuis Reuter (Hemiptera: Miridae), an emerging threat in the cultivation of tomato in Northwest Europe

As non-chemical methods are not always effective to manage pests, the search for chemical solutions that efficiently combat pest species, while safeguarding the environment and beneficial organisms, is essential for advancing effective Integrated Pest Management (IPM) programs. Here, we investigated the efficacy of commercially available pesticides in managing Nesidiocoris tenuis, an emerging threat in the cultivation of tomato in Northwest Europe, while preserving the biocontrol agent Macrolophus pygmaeus. Fourteen pesticides were assessed for their residual toxicity on adults and nymphs in laboratory experiments, after which the most promising candidate was evaluated in cages and semi-commercial greenhouse conditions. Among the pesticides tested, chlorantraniliprole, hexythiazox, tebufenozide and azadirachtin had minimal impact on both insect species, with less than 37.5% corrected mortality. Pirimicarb, sulfoxaflor, acetamiprid, flupyradifurone, thiacloprid, tebufenpyrad, spinosad, indoxacarb, and a mixture of pyrethrins and piperonyl butoxide were harmful to N. tenuis, but also affected M. pygmaeus (up to 100% mortality). Emamectin benzoate was moderately effective to N. tenuis adults (87%) and nymphs (80%), but had limited effects on M. pygmaeus. Application of emamectin benzoate at the maximum recommended concentration resulted in a significantly higher mortality of N. tenuis adults (85%) compared to M. pygmaeus (53%) in cage experiments, while it significantly reduced N. tenuis nymphs and the number of necrotic rings in a greenhouse experiment. Emamectin benzoate emerges as a promising candidate for inclusion in IPM programs. However, further research is necessary to determine its compatibility with other management strategies for controlling N. tenuis and other tomato pests.

Evaluation of non-chemical weed control methods in wheat (Triticum aestivum L.)

Evaluation of non-chemical weed control methods in wheat (Triticum aestivum L.)

Exploring biocidal effects of methyl salicylate and limonene toward &lt;em&gt;Trogoderma granarium&lt;/em&gt; Everts

The khapra beetle, Trogoderma granarium, poses a significant threat as a post-harvest pest in stored products and stands out as a crucial quarantine concern globally. Unlike many other stored product pests, this species proved challenging to manage using conventional insecticides and alternative non-chemical methods. The exploration of plant-based natural products, particularly essential oils, as alternatives arises in response to challenges associated with the prolonged use of synthetic insecticides. While essential oils show promising activity, their use encounters challenges associated with standardization. This study investigates the feasibility of employing some single chemical compounds widespread in several essential oils with insecticidal activity as candidate insecticides, specifically limonene and methyl salicylate in contact/fumigation bioassays toward T. granarium adults. The results showed that methyl salicylate caused a lethal time of 50% (LT50) at the dose of 1 mg after 7.40 hours of exposure. The LT50 calculated for limonene was 86.83 hours while positive control using deltamethrin, used at the recommended dose of the manufacturer, was 5.20 hours after exposure. These data suggest that methyl salicylate can be exploited as a candidate for further tests in field conditions toward T. granarium also in consideration of its relative low toxicity for humans.

Management of Herbicide resistant Phalaris minor: A Review

Littleseed canarygrass (Phalaris minor Retz), an annual species of the family Poaceae, is a major weed problem in many wheat-producing countries. The excessive dependence on herbicides for its control led to the evolution of multiple herbicides resistance and yield losses. The first case of resistant P. minor in India was to the Photosystem-II inhibitor isoproturon in the early 1990’s. P. minor has been found resistant to Acetolactate Synthase (ALS) inhibitors, Acetyl-CoA Carboxylase (ACCase) inhibitors, Photosystem II inhibitors. It is highly competitive and in severe cases can cause complete crop failure, forcing farmers to harvest their crop as fodder or ploughing the standing crop along with weeds. For management of these multiple herbicide resistant P. minor, pyroxasulfone, pendimethalin, flumioxazin, trifluralin and flufenacet can be used as alternative herbicides. Moreover, in-depth biological and ecological studies on P. minor should be carried out for devising integrated weed management strategies. The long-term strategies of efficient weed management and sustainability of wheat production should include the use of alternative herbicides, herbicide mixture, crop rotation along with other non-chemical methods like manual removal of weeds, mulching, Summer ploughing etc providing the competitive advantages to the wheat crop over P. minor, at the same time increasing the profitability of the farmer by controlling the weed effectively and reducing the selection pressure on the weeds which will inturn reduce the resistance development in weeds