Non-chemical Methods Research Articles

The effect of ultraviolet diode radiation on the growth rate of Alternaria colonies

Phytopathogenic micromycetes induce dangerous crop diseases. Traditionally, fungicides have been used to prevent these diseases. In recent years, environmentally friendly non-chemical methods for combating fungal infections have been developed. In particular, ultraviolet (UV) treatment of various wavelengths, intensities and origins has been shown to be effective. In this work, we have analysed the effect of diode low-intensity shortwave UV radiation (UV-C) on the growth and potential viability of the mycelium of Alternaria radicina and A. alternata, the pathogens of important crops. It was shown that irradiation by UV-C diode inhibited growth of Alternaria species at the early stages of development. This effect was high in the first 3 d after UV exposure; however, after 5 d after irradiation, the growth of pathogenic fungi fully restored, suggesting that UV can be only used for partial removal of Alternaria. It was found that A. alternata is less sensitive to diode UV irradiation. The obtained results indicate that the Alternaria micromycetes, particularly, A. alternata, containing high melanin levels, are resistant to low-intensity UV-C diode irradiation.

Effects of cereal rye seeding rate on waterhemp (Amaranthus tuberculatus) emergence and soybean growth and yield

AbstractThe evolution of herbicide-resistant weeds has resulted in the necessity to integrate nonchemical control methods with chemicals for effective management in crop production systems. In soybean, control of the pigweed species, particularly herbicide-resistant waterhemp and Palmer amaranth, have become predominant concerns. Cereal rye planted as a winter cover crop can effectively suppress early-season weed emergence in soybean, including waterhemp, when planted at a rate of 123 kg ha−1. The objectives of this study were to determine the effects of different cereal rye seeding rates (0, 34, 56, 79, 110, and 123 kg ha−1) on early-season waterhemp suppression and soybean growth and yield. Soybean was planted into fall-seeded cereal rye, which was terminated within 4 d of soybean planting. The experiment was conducted over the 2018, 2019, and 2020 growing seasons in Columbia, Missouri. Effects of cereal rye on early-season waterhemp suppression varied by year and were most consistent at 56 kg ha−1 or higher seeding rates. Linear regression analysis of cereal rye biomass, height, or stand at soybean planting showed inverse relationships with waterhemp emergence. No adverse effects on soybean growth or yield were observed at any of the cereal rye seeding rates relative to plots that lacked cereal rye cover. Result differences among the years suggest that the successfulness of cereal rye on suppression of early-season waterhemp emergence is likely influenced by the amount of waterhemp seed present in the soil seed bank.

IPSIM-Cirsium, a Qualitative Expert-Based Model to Predict Infestations of Cirsium arvense

Throughout Europe, Cirsium arvense is the most problematic perennial weed in arable crops, whether managed under organic or conventional agriculture. Non-chemical control methods are limited with partial efficacy. Knowledge is missing on their effect across a wide gradient of cropping systems and pedoclimates. To achieve effective Cirsium arvense management ensuring crop productivity while limiting the reliance of cropping systems on herbicide, expert-based models are needed to gather knowledge on the effect of individual levers and their interactions in order to (i) design and assess finely tuned combinations of farming practices in different pedoclimates and (ii) support decisions for Cirsium arvense control. Based on expert-knowledge and literature, we developed IPSIM-Cirsium, a hierarchical qualitative model which evaluates the infestation of Cirsium arvense as a function of farming practices, climate conditions, soil descriptors and their interactions. IPSIM-Cirsium is a multi-attribute model considering all possibilities of interactions between factors, it estimates the infestation rate of the field graded according to a four-level scale. The model outputs were confronted to independent field observations collected across 6 fields, over a 16-year period in 3 sites. IPSIM-Cirsium showed a satisfactory predictive quality (accuracy of 78.2%). IPSIM-Cirsium can be used as a tool for crop advisors and researchers to assist the design of systems less reliant on herbicides, for farmers and advisers to assess ex-ante prototypes of cropping systems, and for teachers as an educational tool to share agroecological weed management knowledge.

COMPARATIVE STUDY OF MAJOR DISEASES OF MAJOR SUMMER VEGETABLES AND THEIR MANAGEMENT PRACTICES IN SYANGJA, NEPAL

Plant diseases are one of the major factors of crop yield loss during production process. Different disease management methods have been innovated including chemical to biological methods. Different types of cultural methods for the disease control are also evolving. In this study, we found out the different plant diseases occurring in summer vegetables in syangja district and compare the management practices, which are being used by conventional and commercial farmers. For this, farmers were asked questions related to the symptoms of diseases and the management practices which they are using for the control of disease. 72.9% of farmers pointed out disease as the major problem in summer vegetable. More number of Commercial farmers (75%) were found to use both chemicals and non-chemical disease management methods than conventional farmers. Botanical pesticides was in more use in commercial farms than in conventional farms. Not only botanical pesticides, chemical pesticides were also more in use in commercial farms. Commercial farms were found to use both chemical and botanical pesticides according to severity of disease. Conventional farmers were found to use a greater number of chemical pesticides as compare to botanical pesticides because of lack of knowledge and quick action of chemical pesticides.

Pathogenicity of two fungal pathogens on larvae of the elm leaf beetle, Xanthogaleruca luteola Muller (Coleoptera: Chrysomelidae)

BackgroundThe elm leaf beetle (ELB), Xanthogaleruca luteola Muller (Coleoptera: Chrysomelidae), is one of the most important insect pests that cause damage and physiological stress for the trees. In the present research, pathogenicity of both entomopathogenic fungi (EPF), Beauveria bassiana and Metarhizium anisopliae on the 1st, 2nd, and 3rd instar larval of ELB at the concentrations of 105, 106, 107, and 108 conidia per ml, using immersion and spray methods and were evaluated.ResultsThe results showed that LC50 of B. bassiana in immersion and spray methods were 3.88 × 102 and 7.52 × 102 conidia/ml, while LC50 of M. anisopliae in mentioned methods were 7.05 × 102 and 11.85 × 102 conidia/ml, respectively. The highest mortality rate in both EPF was observed in the 1st instar larvae that were significantly different than the control treatment. Moreover, the highest and lowest mortality in both EPF, using immersion and spray methods, were observed at the concentrations of 108 and 105 conidia/ml, respectively. Therefore, susceptibility of 1st and 2nd larval instars was more than 1st instar larvae. Based on the findings of the present study, there was no mortality during the first 24 h, while after 2 days, the mortality was recorded and increased over time in case of both pathogens. Accordingly, B. bassiana and M. anisopliae were pathogenic on larvae of ELB.ConclusionsThe outputs of the study demonstrated that applications of these eco-friendly fungal pathogens with other non-chemical methods are recommended. Of course, under natural conditions, their efficiency may change; thus, more comprehensive studies are necessary.

Comparative Analysis of Microwave and Electric Arc as a New Method in Weed Control

The increase in the demand for organic production and the adverse effects of chemicals used in agriculture have brought non-chemical weed control methods to the fore. Among these methods, the most studied ones are microwave and electric arc methods. It has been determined in studies that microwaves and electric current, when applied at the correct power level and for sufficient time, biologically inactivate weeds, all kinds of unwanted plants and seeds. In this study, the mortality rates caused by microwave energy and electric current (arc) methods in some plants applied under laboratory conditions were compared. Studies have shown that the effectiveness of microwave and electric arc methods depends on the selected current, voltage, power level and exposure time. It is thought that the electric arc method is easier and more economical in terms of application in the field than the microwave method. Another purpose of this study is to remind agricultural policy makers and decision makers of the importance of alternative weed control methods and to ensure that they make policies in this direction.

Comparative Analysis of Microwave and Electric Arc as a New Method in Weed Control

The increase in the demand for organic production and the adverse effects of chemicals used in agriculture have brought non-chemical weed control methods to the fore. Among these methods, the most studied ones are microwave and electric arc methods. It has been determined in studies that microwaves and electric current, when applied at the correct power level and for sufficient time, biologically inactivate weeds, all kinds of unwanted plants and seeds. In this study, the mortality rates caused by microwave energy and electric current (arc) methods in some plants applied under laboratory conditions were compared. Studies have shown that the effectiveness of microwave and electric arc methods depends on the selected current, voltage, power level and exposure time. It is thought that the electric arc method is easier and more economical in terms of application in the field than the microwave method. Another purpose of this study is to remind agricultural policy makers and decision makers of the importance of alternative weed control methods and to ensure that they make policies in this direction.

Ecofriendly nonchemical/nonthermal methods for disinfestation and control of pest/fungal infestation during storage of major important cereal grains: A review

AbstractIn this review, numerous control methods for stored grain insects are discussed in detail with emphasis on the nonchemical/nonthermal methods. Grain infestation by insects and molds is one of the major problems that need attention as these pests deteriorate the quality of food grains and their products. A number of modern nonchemical methods have been found to be effective against insect pests, such as microwave and infrared heating. Besides those, nonthermal methods, such as ozone treatment and ultraviolet heating, are also gaining importance, as they prove to be much safer tools for the management of pests and molds. In a nutshell, these nonchemical/nonthermal methods have emerged as a plausible alternative to chemical fumigants which may have a deleterious effect on the food product quality from a nutritional point of view. Thus, the objective of this study was to explore the published research works on different control approaches applied on grains for protection against stored insect pests and molds. Three nutritionally and economically important cereal grains, wheat, rice, and maize, which contribute to the world economy in terms of production, are covered in the review. Also, the emphasis is given to the best physical nonchemical methods/nonthermal methods of disinfestation/disinfection of insects and molds: microwave, infrared, and ultraviolet heating as well as ozone treatment. Of all the nonchemical/nonthermal methods, microwave and ozone heating could be possible alternatives for achieving 100% mortality of insects and molds and 50–80% in the case of infrared and ultraviolet provided the grains are at the initial stage of infestation.

Influence of Physicochemical Characteristics of Bean Crop Soil in Trichoderma spp. Development

Spain has ranked 6th on the harvested bean area and 8th in bean production in the European Union (EU). The soils of this area have mixed silt loam and sandy loam texture, with moderate clay content, neutral or acidic pH, rich in organic matter and low carbonate levels, providing beans with high water absorption capacity and better organoleptic qualities after cooking. Similar to other crops, it is attacked by some phytopathogens. Hitherto, chemical methods have been used to control these organisms. However, with the Reform of the Community Agrarian Policy in the EU, the number of authorized plant protection products has been reduced to prevail food security, as well as to be sustainable in the long term, giving priority to the non-chemical methods that use biological agents, such as Trichoderma. This study aimed to investigate the relative importance of various crop soil parameters in the adaptation of Trichoderma spp. autoclaved soils (AS) and natural soils (NS) from the Protected Geographical Indication (PGI) “Alubia La Bañeza—León” that were inoculated with Trichoderma velutinum T029 and T. harzianum T059 and incubated in a culture chamber at 25 °C for 15 days. Their development was determined by quantitative PCR. Twelve soil samples were selected and analyzed from the productive zones of Astorga, La Bañeza, La Cabrera, Esla-Campos and Páramo. Their physicochemical characteristics were different by zone, as the texture of soils ranged between sandy loam and silt loam and the pH between strongly acid and slightly alkaline, as well as the organic matter (OM) concentration between low and remarkably high. Total C and N concentrations and their ratio were between medium and high in most of the soils and the rest of the micronutrients had an acceptable concentration except for Paramo’s soil. Both Trichoderma species developed better in AS than in NS, T. velutinum T029 grew better with high levels of OM, total C, ratio C:N, P, K, Fe, and Zn than T. harzianum T059 in clay soils, with the highest values of cation exchange capacity (CEC), pH, Ca, Mg and Mn. These effects were validated by Canonical Correlation Analysis (CCA), texture, particularly clay concentration, OM, electrical conductivity (EC), and pH (physical parameters) and B and Cu (soil elements) are the main factors explaining the influence in the Trichoderma development. OM, EC, C:N ratio and Cu are the main soil characteristics that influence in T. velutinum T029 development and pH in the development of T. harzianum T059.

Fungicide Resistance in Botrytis in Danish Strawberry Production

A fungicide resistance survey of Botrytis populations in Danish strawberry fields was conducted in 2015 to 2019. Among 594 isolates from 46 fields under integrated pest management, 40% were resistant to fenhexamid, 76% to QoI fungicides, 57% to boscalid and 59% to anilinopyrimidines. These resistance levels were higher than in Northern Germany during the same period, reflecting the more frequent use of the corresponding commercial fungicides in Denmark. In contrast, resistance to fludioxonil (21%) was lower in Denmark than in Northern Germany. Fungicide resistance generally increased with the age of strawberry fields. Isolates with multiple resistance to the registered fungicides were more likely than sensitive isolates to possess resistance also to iprodione and thiophanate-methyl, two fungicides which were no longer used in Denmark during the sampling period. This coupling of resistance to current and old fungicides is interpreted as evidence of a differentiation of Botrytis populations into strains with enhanced and reduced competence to develop fungicide resistance. In order to retard resistance development, adjustments to Danish fungicide registration for strawberries are recommended. Further, non-chemical control methods such as removing infected fruit at harvest should be implemented.

Physical Crop Postharvest Storage and Protection Methods

Sustainable and organic plant production uses natural products and natural self-regulation processes occurring in the ecosystem. The awareness is growing and the demands of consumers are higher and higher. One solution is to use various methods, as an alternative to pesticides. It is also very important to care for the stored crops after harvesting especially using non-chemical methods. The physical method of plant protection consists in treating the harmful organism with physical factors such as temperature, its same light and radiation, controlled atmosphere, special packaging, pressure, various sounds, ozone, and low-temperature plasma. The availability of effective application techniques opens up new possibilities for the storage of crops in order to maintain their health and quality for a long time. This review focuses on the analysis of physical methods of postharvest protection, especially the latest methods using ozone and low-temperature plasma. As a result, consumers of agricultural crops will be able to consume food free of insects, mycotoxins and pesticide residues.

Does the Presence of Other Egg Rafts and Conspecific Larvae Encourage Oviposition by the Mosquito, Culex sitiens (Diptera: Culicidae)?

Mosquitoes include many major disease vectors and are often controlled in their aquatic larval stage, since they are living in defined habitats. However, non-chemical methods of control are influenced by the female oviposition behavior, and this is affected by many factors. Many mosquito species choose to oviposit on water containing egg raft pheromones (which have thus been used in control), showing another female has selected that pool as being best. However, Culex sitiens did not respond chemically to water previously containing egg rafts, but unlike most species, did strongly respond visually to artificial black egg rafts floating on the surface. Oviposition increased as the number of artificial egg rafts increased up to six, but more rafts gave no further increase. However, even nine egg rafts had no repellent effect, despite the high probability of larval overcrowding and thus starvation. Altering the pattern with which five rafts were interconnected and also altering the size of individual rafts seemed to show that the mosquitoes were responding more to total raft area rather than number. The presence of either 2nd instar or 4th (final) instar conspecific larvae in the water can be detected chemically but did not influence oviposition, either positively or negatively. Conspecific larvae show the water is suitable for oviposition, but they are competitors for the available food and so many studies have shown especially older larvae to be repellent to oviposition. Culex sitiens was thus not responding chemically to either eggs or larvae but unusually had a visual response.

Usage of Non-chemical Methods to Counter the Damages Caused by Tomato Mosaic Virus

Background: Tomato mosaic virus (ToMV) is the most common and important pathogen of tomato crop. The infected plants show mosaic, mottle, wrinkling, reduced leaf size and uneven ripening of fruits. ToMV is transmitted mechanically, by cultural operations, farm implements and also through seed. Methods: The present study was planned to evaluate environment friendly strategies for the management of ToMV disease. Different non-chemical means viz., Elephant Ear plant extract, Eucalyptus extract, Zinc and Boron solution, NPK solution, Milk and Urea were used on four tomato varieties (Tanja, Chico, Manik and Sahil). All the treatments were used at three different concentrations (1%, 2% and 3%) and replicated three times. Result: The maximum disease reduction was recorded in plants treated with NPK solution (16.35%) and minimum in plants treated with Elephant Ear plant extract (29.65%). The maximum mean disease severity was recorded at 1 percent concentration of all the treatments (32.46%) which was statistically significant from that of 2 and 3% (24.74% and 19.23%), respectively. Among the varieties, minimum disease severity was recorded in Manik (24.64%) variety and maximum in Chico (31.27%) variety. All the treatments contributed towards reduction in disease severity of which NPK solution being most efficient.

Glodari i njihova kontrola u voćnjacima

The number of mouse-like rodents was monitored based on the traces and the estimates of the active holes in a private orchard from February to October 2019. Based on the appearance and spatial arrangement of the active holes on the observed orchard plot, the presence of the field vole Microtus arvalis (Pallas 1778) and the field mouse Apodemus agrarius (Pallas, 1771) was determined. Until 2019, the control of the rodent population at this location was successfully implemented through an integrated approach and the application of many non-chemical methods and procedures. Considering the mass appearance of these organisms during the research period, which was determined by constant monitoring, the chemical control had to be implemented to avoid major economic damage and defects to young seedlings. In the chemical control a zinc-phosphide based rodenticide with 2% active substance, which belongs to the group of fast-acting rodenticides with an acute and respiratory effect, was used. The effectiveness of rodenticide formulations was evaluated according to the Henderson & Tilton formula, based on the number of active holes for 7, 14 and 28 days. The best efficiency of the applied rodenticide was registered in the 28-days spring control period (85.11%) and in the 14days autumn period (74.03%) and 28days autumn period (82.14%).

Striped cucumber Beetle and Western Striped Cucumber Beetle (Coleoptera: Chrysomelidae)

Abstract The striped cucumber beetle [StCB; Acalymma vittatum (F.) (Coleoptera: Chrysomelidae)] and the western striped cucumber beetle [WStCB; Acalymma trivittatum (Mannerheim)] are closely related species of herbivores endemic to North America that specialize on Cucurbitaceae plants. StCB and WStCB are key pests of cucurbit crops that can reduce quantity and quality of yield or even kill plants, especially seedlings, by feeding and by vectoring pathogens. Insecticides can be used to control StCB and WStCB, but a number of more selective nonchemical management methods are also available to help control these pests. Here, we describe the biology, life stages, and damage caused by StCB and WStCB and discuss methods for managing these pests in cucurbit crops.

Compost bacteria as potential agents in biological plant control

The assumptions of integrated pest management put great emphasis on the development of non-chemical methods which increases the interest in biological methods and the search for microorganisms that would be an alternative to the most frequently used fungicides. The aim of the experiments was the isolation of the compost bacteria, in vitro determination of their fungistatic activity against some pathogenic fungi of the genus Fusarium, Alternaria, Sclerotinia, Botrytis, Rhizoctonia and Pythium and identification of selected isolates. From the backyard compost, 44 bacterial strains were isolated and assessed for the fungistatic properties by the well diffusion method. The obtained results allowed for the selection of 12 isolates of compost bacteria, characterised by the broadest and the strongest fungistatic activity spectrum against tested fungi. Identification of bacterial isolates by: MALDI-TOF mass spectrometry and 16S rRNA gene sequencing methods showed their belonging to the species Bacillus subtilis, Alcaligenes faecalis, Stenotrophomonas maltophilia and Serratia liquefaciens.

Use of non-chemical methods for the management of southern blight disease of carrot incited by Sclerotium rolfsii

This experiment was conducted to assess the effect of Trichoderma harzianum, soil solarization, and biofumigant on southern blight dis-ease of carrot incited by Sclerotium rolfsii isolate CS 5. A series of in-vitro and in-vivo trials laid out to select a virulent isolate of S. rolfsii against the carrot variety New Kuroda and evaluated the mustard, cabbage, cauliflower, and broccoli leaf extracts for choosing an effec-tive biofumigant against test pathogen. Mustard was the most effec-tive in inhibiting the radial growth, and sclerotia formation (80.37 and 83.37%) of S. rolfsii (isolate CS 5) at 40% level of concentration followed by cabbage leaf extract (62.22 and 68.69%). On the contrary, a total of 10 isolates of T. harzianum were screened against the test pathogen on Potato Dextrose Agar (PDA) medium for choosing a dominant isolate of T. harzianum. The isolate Th-6 was found as the most active in inhibiting the radial growth (84.44%) of S. rolfsii fol-lowed by Th-1 (75.56%). In the application of T. harzianum, biofumi-gation, and soil solarization, the treatment appeared to be the most superior in reducing pre- and post-emergence mortality of carrot during secondary field trials. The lowest southern blight disease inci-dence (10.77%), and disease severity (12.78%) were found at the same treatment. Subsequently, the yield of carrot was increased 155.18% which might be due to the reduction of carrot disease as well as the addition of organic materials in the soil.

Toxicological and ecotoxocological characteristics of pesticides important for their sustainable use

Modern concept of reducing the risk of pesticide use is based on the concept of sustainable use of pesticides. The concept of sustainable use of pesticides presents the range of professional rules, acts, skills of the pesticides use with the aim to promote the plant protection with decreased usage of pesticides, providing, whenever it is possible, advantage to non-chemical methods of plant protection. The most important part of sustainable pesticide usage is integrated plant protection. Integrated plant protection implies the application and integration of all available methods of plant protection which prevent the development of population of the harmful organisms above the level of harmfulness, considering that the usage of means for plant protection is at the level which is economically and ecologically justified. Risks for the human health and the environment is decreased or at least reduced to the minimum by the concept of pesticide application according to the integrated plant protection. Pesticides have certain potential to cause damage effect if people and the other organisms are exposed at the certain conditions and amount. Modern toxicology is directed to determine the safe dose, meaning the dose without the harmful effect as well as finding out the way of safe pesticide use. Considering the modern toxicology, two important terms are hazard and risk. Hazard is the intrinsic characteristic of the chemicals to cause the harmful effect at the defined conditions of the exposition. Risk is probability of manifestation of the harmful effect at the certain conditions of the exposition. The harmful effects of pesticides on humans mostly depend on the pesticides’ own toxicity but on the human’s exposure as well. The exposure of people to pesticides can appear at the working place. Farmers can be exposed to pesticides during the work in the open field and protected space, while the significant exposure can appear with workers in the pesticide industry as well as with workers who deal with jobs of deratization and disinsection and with workers in pesticides wholesale and retail. Estimation of the exposure of the agricultural workers is complex. Professional users are mostly exposed but the exposure is episodic. The particular problem is estimation of the exposure of the field workers and their householders as well. Therefore, while estimating the people’s exposure to pesticides in theresidential buildings, the remains of the pesticides in water, food, dust and air in and around the house is considered. Increased amounts of the pesticides in the house dust are related to exposure which depends on the distance between houses and the pesticide-treated fields, exposure in the house due to the fact that one or two householder work in the agriculture and larger use of pesticides in the residential buildings for treating different insects in the house or yard. Pesticides, besides their negative effects on people’s health, can have harmful effect on the environment, meaning that they can contaminate surface and underground water, soil and air, and to have toxic effects onto non-target organisms. There is a large number of documented papers where is proved that use of pesticides has great consequences onto the population of autochthonous wild animals. Integrated plant protection and sustainable use of pesticides cannot be only a declarative determinant. A wide range of steps have to be undertaken to enable their use in practice. Future imposes huge professional challenges related to the use of pesticides. The need to fulfill the different, sometimes even opposite demands is often imposed. On one side it is demanded to provide pesticides efficiency in protection from the harmful organisms and on the other side sustainable use and decreasing the risk for people and environment. Development of the new pesticides with the new ways of action and improved safety profiles and application of the alternative systems of plant production which will be less dependent on the pesticides could reduce the exposure to pesticides and side effects on people. The use of appropriate and well maintained equipment for pesticide use, while taking all protection measures at all stages of pesticides handling, can reduce the exposure to pesticides. Implementing the concept of sustainable use of pesticides is difficult, but for now it is the only promising way to ensure the protection of people, the environment and the production of healthy food.

Surface preparation by mechanical polishing of the 1.3-GHz mono-cell copper cavity substrate prior chemical etching for niobium coating

Surface quality of the substrate is widely acknowledged to be essential for the niobium thin film deposition. Much effort has thus been spent to improve the surface roughness by using various chemical etching techniques. However, surface preparation before the chemical etching also plays a part in obtaining a satisfactory substrate, but has rarely been studied before. This paper aims to define a specification for the pre-polished copper substrate prior chemical etching and searches for suitable alternative non-chemical grinding methods for the copper cavity. Copper samples were mechanically pre-polished at first by using flap sanding wheels of different grits and then chemically etched by using the well-established SUBU solutions. Surface roughness, as a figure of merit, was measured and compared before and after SUBU. Optimum practice for pre-polishing may therefore be determined. The mechanical grinding was subsequently applied on the 1.3-GHz mono-cell copper cavity. Meantime, the previously reported centrifugal barrel polishing method was also applied with new abrasive materials and modified schemes. A comprehensive study of etching rate, surface roughness and morphologies was conducted. The specification for surface roughness prior SUBU was determined. Due to a complex geometry and curved surfaces possessed by the 1.3-GHz copper cavity, the traditional mechanical grinding was proved to be not ideal. Satisfactory surface quality was obtained by using the alternative centrifugal barrel polishing on the cavity. The proposed new scheme and new abrasive materials were demonstrated to be effective, and a mirror-like surface was achieved on the copper cavity. The traditional mechanical grinding can therefore be replaced. This constitutes a dedicated study on pre-polishing of the 1.3-GHz copper cavity substrate prior chemical etching for niobium sputtering.

Syngenta's contribution to herbicide resistance research and management.

The evolution of weed resistance to herbicides is an ever‐increasing problem that affects crop yield and food production. In Syngenta, we believe that this difficult and complex issue can be most efficiently addressed through a deep understanding of the evolutionary dynamics and mechanism of resistance. A profound knowledge of resistance is key to developing the next generation of resistance‐breaking compounds with existing or novel herbicide sites of action. We use a multidisciplinary laboratory‐based, glasshouse and field biology approach to study herbicide resistance and provide strong science‐based solutions to delay the onset and manage resistance. We have developed and implemented simple early‐season resistance detection methods to allow farmers make an informed decision for effective weed control. We have built mechanistic, individual‐based computer models to design profitable, long‐term sustainable weed management programs. Our zero tolerance approaches employ herbicides with different sites of action, applied in mixtures and sequences, to minimise the risk of resistance evolution. Weeds are targeted at the right growth stage with optimal herbicide formulation and spray technology for maximising weed control and depleting the seed bank. We are promoting the use of competitive crop varieties and other nonchemical methods for an integrated weed management strategy. We have a global web of external collaborations for studying and managing herbicide resistance. We are committed to farmers' education and training on herbicide resistance, and regularly share our methods and findings via conferences and peer‐reviewed scientific publications for the benefit of the wider weed science community and field practitioners. © 2020 Society of Chemical Industry