Fine mapping and characterization of stripe rust resistance gene YrAYH in near-isogenic lines derived from a cross involving wheat landrace Anyuehong

Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is a devastating disease in wheat worldwide.Discovering and characterizing new resistance genes/QTL is crucial for wheat breeding programs.In this study,we fine-mapped and characterized a stripe rust resistance gene,YRAYH,on chromosome arm 5BL in the Chinese wheat landrace Anyuehong(AYH).Evaluations of stripe rust response to prevalent Chinese Pst races in near-isogenic lines derived from a cross of Anyuehong and Taichung 29 showed that YrAYH conferred a high level of resistance at all growth stages.Fine mapping using a large segregating population of 9748 plants,narrowed the YRAYH locus to a 3.7 Mb interval on chromosome arm 5BL that included 61 annotated genes.Transcriptome analysis of two NIL pairs identified 64 upregulated differentially expressed genes(DEGs)in the resistant NILs(NILs-R).Annotations indicated that many of these genes have roles in plant disease resistance pathways.Through a combined approach of fine-mapping and transcriptome sequencing,we identified a serine/threonine-protein kinase SRPK as a candidate gene underlying YrAYH.A unique 25 bp insertion was identified in the NILs-R compared to the NILs-S and previously published wheat genomes.An InDel marker was developed and co-segregated with YrAYH.Agronomic trait evaluation of the NILs suggested that YrAYH not only reduces the impact of stripe rust but was also associated with a gene that increases plant height and spike length.

Comprehensive Overview and Analytical Study on Automatic Bird Repellent Laser System for Crop Protection

Birds are a huge hazard to agriculture all around the world,causing harm to profitable field crops.Growers use a variety of techniques to keep them away,including visual,auditory,tactile,and olfactory deterrents. This study presents a comprehensive overview of current bird repellant approaches used in agricultural contexts,as well as potential new ways. The bird repellent techniques include Internet of Things technology,Deep Learning,Convolutional Neural Network,Unmanned Aerial Vehicles,Wireless Sensor Networks and Laser biotechnology. This study’s goal is to find and review about previous approach towards repellent of birds in the crop fields using various technologies.

DNA Barcoding of Insects and Its Direct Application for Plant Protection

The introduction of invasive insect pests across national borders has become a major concern in crop production. Accordingly, national plant protection organizations are challenge to reinforce their monitoring strategies, which are hampered by the weight and size of inspection equipment, as well as the taxonomic extensiveness of interrupted species. Moreover, some insect pests that impede farmer productivity and profitability are difficult for researchers to address on time due to a lack of appropriate plant protection measures. Farmers’ reliance on synthetic pesticides and biocontrol agents has resulted in major economic and environmental ramifications. DNA barcoding is a novel technology that has the potential to improve Integrated Pest Management decision-making, which is dependent on the ability to correctly identify pest and beneficial organisms. This is due to some natural traits such as phenology or pesticide susceptibility browbeaten by IPM strategies to avert pest establishment. Specifically, Deoxyribonucleic acid (DNA) sequence information was applied effectively for the identification of some micro-organisms. This technology, DNA barcoding, allows for the identification of insect species by using short, standardized gene sequences. DNA barcoding is basically based on repeatable and accessible technique that allows for the mechanisation or automation of species discrimination. This technique bridges the taxonomic bio-security gap and meets the International Plant Protection Convention diagnostic standards for insect identification. This review therefore discusses DNA barcoding as a technique for insect pests’ identification and its potential application for crop protection.

Botanicals and plant strengtheners for potato and tomato cultivation in Africa

This review provides a summary of botanicals and plant strengtheners that have potential uses for disease and pest management in potato and tomato cultivation in African.We discuss their possible use to prevent major diseases and pests which infest potato and tomato,such as early and late blight,bacterial wilt,potato tuber moth,and tomato leafminer.There are several examples of the successful uses of botanicals for pathogen and pest control relevant for different African climatic conditions;however,most of these studies have been conducted in vitro and often lack field verification.Plant strengtheners(substances that induce and improve crop resistance,yield,and quality)are little studied and used in Africa in comparison to North America and Europe.The possible benefits of using botanicals and plant strengtheners instead of conventional pesticides are discussed here in relation to human health and the environment as well as their modes of action and accessibility to farmers.Lack of knowledge of the composition and active ingredients of extracts,environmental concerns,uncertainties regarding stability and formulation,lack of legislation and limited support from governments,hamper the development of botanicals and plant strengtheners for use in sustainable African agriculture.

Application of Temporary Technology for Soil and Water Conservation in Crop Protection

The increasing of highway engineering construction makes soil and water loss surrounding highway and also influences the growth of crops around, To control soil and water loss, new engineering measures are put forward to protect soil and water and prevent crops from being damaged.

Natural Enemies and Pest Control in Field-Grown Crop in Southern Senegal

Crop pests are a permanent threat to horticultural production. Several control methods are recommended for their control, including biological control. This method based on the use of natural enemies is not well established. The objective of this study was to assess the diversity and abundance of natural enemies of crop pests. A survey of crops associated with pests was carried out on 144 fields in southern Senegal to measure the diversity and abundance of natural enemies of various crop pests, determine the native parasitoid complex and assess parasitism rates. Ecological indices were calculated to assess the diversity of natural enemies. A total of 25 natural enemy species were identified, including 15 parasitoids and 10 predators. Predatory Hemiptera and Parasitoid Hymenoptera were high biodiversity. The parasitism rates vary between 0 and 50% depending on the abundance of pests and parasitoid species. Knowledge of the diversity of natural enemies and the understanding of trophic interactions with pests are important in the development of biological crop protection in order to preserve resilience in agroecosystems.

The Resistance of Crops in Plant Protection

World crop production requires highly-productive varieties of agricultural crops,which are resistant to pest organisms.Such varieties are also of great importance for the Uzbekistan.Their

Controlling Greenhouse Whitefly with Erectomoceru s eremicus Rose&Zolnerowich and Crude Plant Extracts of Garlic and Chilli Improves Yield of Tomato

Despite its economic importance of tomato(Solamum lycopersicum L.),many growers are unable to achieve maximum yield of high quality due to insect pest infestation.This study was aimed at determining the effec-tiveness of parasitoid Eretmocerus eremicus and crude plant extracts of garlic and chilli as an integrated alternative control method of greenhouse whitefly(GHW)on yield of tomato variety“Anna F1”The study was.conducted at Egerton University using a split plot arrangement in ran-domized complete block design,replicated three times.Parasitoid was the main plot factor at two levels(with and without E.eremicus)while sprays of distilled water(negative control),Abamectin(positive control),chilli and garlic extracts formed the sub-plot factors.Data on GHW incidence,population density,parasitisation rate,and yield was collected.Data collected was subjected to analysis of variance and means of significant treatments separated using Tukey's test at p=0.05.Botanical extracts and E.eremicus helped to control whitefly population,infestation,and in en-hancing growth and yield of greenhouse tomato plants compared to where they were not applied.Botanical plant extracts and/or E.eremicus can be used in the management of GHW and to improve tomato yields.

QUANTITATIVE STUDY ON ANTI-PEST ACTIVITY OF NATURAL PRODUCTS BASED ON VISUALIZATION FRAMEWORK OF KNOWLEDGE GRAPH

To help in the prevention of large-scale loss of agricultural production caused by crop pests,a visual analysis was performed on the main research areas,key countries,organizational cooperation,citation sources and current trends in pest research by searching the literature of Web of Science database and using CiteSpace 5.8.R3 and VOSviewer 1.6.18 software.Additionally,the effects and mechanisms of natural products with anti-insect activity were summarized through visual analysis.According to the bibliometric analysis,keywords such as mortality(232 occurrences),natural enemy(232 occurrences)and spinosad(110 occurrences)were common,and insecticides and natural enemies of pests were the main methods for killing pests.However,pesticide use exhibits numerous limitations.Co-occurring terms in visualization analysis mainly included residue(193 occurrences),detection(153 occurrences),degradation(133 occurrences),recovery(103 occurrences),pyrethroid(97 occurrences)and pesticide residues(65 occurrences).Thus,pesticides cannot fundamentally solve food security;pesticides also pollute the environment and endanger human health.Therefore,green and efficient pesticides that can replace synthetic pesticides are urgently needed.Natural products have recently gained attention in Brazil,China,the USA and other countries because they are green and pollution-free,and new natural pesticides have been developed.This visual analysis combined data mining with literature review and summarize the anti-pest activities and mechanisms of action of natural products.This information provides a foundation and ideas for researchers to study the application and development of natural products in pest control.

RNA silencing:From discovery and elucidation to application and perspectives

RNA silencing(or RNA interference,RNAi)is a conserved mechanism for regulating gene expression in eukaryotes.The discovery of natural trans-kingdom RNAi indicated that small RNAs act as signaling molecules and enable communication between organisms in different kingdoms.The phenomenon and potential mechanisms of trans-kingdom RNAi are among the most exciting research topics.To better understand trans-kingdom RNAi,we review the history of the discovery and elucidation of RNAi mechanisms.Based on canonical RNAi mechanisms,we summarize the major points of divergence around RNAi pathways in the main eukaryotes’kingdoms,including plants,animals,and fungi.We review the representative incidents associated with the mechanisms and applications of trans-kingdom RNAi in crop protection,and discuss the critical factors that should be considered to develop successful trans-kingdom RNAi-based crop protection strategies.

Root symbionts： Powerful drivers of plant above- and belowground indirect defenses

Soil microbial mutualists of plants, including mycorrhizal ftmgi, non- mycorrhizal fungi and plant growth promoting rhizobacteria, have been typically characterized for increasing nutrient acquisition and plant growth. More recently, soil microbes have also been shown to increase direct plant defense against above- and below- ground herbivores. Plants, however, do not only rely on direct defenses when attacked, but they can also recruit pest antagonists such as predators and parasitoids, both above and belowground, mainly via the release of volatile organic compounds （i.e., indirect defenses）. In this review, we illustrate the main features and effects of soil microbial mutualists of plants on plant indirect defenses and discuss possible applications within the framework of sustainable crop protection against root- and shoot-feeding arthropod pests. We indicate the main knowledge gaps and the future challenges to be addressed in the study and application of these rnultifaceted interactions.

Ambivalent response in pathogen defense: A double-edged sword?

Plants possess effective immune systems that defend against most microbial attackers.Recent plant immunity research has focused on the classic binary defense model involving the pivotal role of small-molecule hormones in regulating the plant defense signaling network.Although most of our current understanding comes from studies that relied on information derived from a limited number of pathosystems,newer studies concerning the incredibly diverse interactions between plants and microbes are providing additional insights into other novel mechanisms.Here,we review the roles of both classical and more recently identified components of defense signaling pathways and stress hormones in regulating the ambivalence effect during responses to diverse pathogens.Because of their different lifestyles,effective defense against biotrophic pathogens normally leads to increased susceptibility to necrotrophs,and vice versa.Given these opposing forces,the plant potentially faces a trade-off when it mounts resistance to a specific pathogen,a phenomenon referred to here as the ambivalence effect.We also highlight a novel mechanism by which translational control of the proteins involved in the ambivalence effect can be used to engineer durable and broad-spectrum disease resistance,regardless of the lifestyle of the invading pathogen.

Soil application of Beauveria bassiana GHA against apple sawfly, Hoplocampa testudinea （Hymenoptera： Tenthredinidae）： Field mortality and fungal persistence

Low impact alternatives to synthetic insecticides for the control of apple sawfly （Hoplocampa testudinea Klug） are scarce encumbering pest management in organic apple orchards. We investigated the soil persistence and field efficacy of the entomopathogenic fungus Beauveria bassiana （Balsamo） Vuillemin （BotaniGard） against apple sawfly under common organic orchard practices. We also assessed the efficacy of B. bassiana GHA and Metarhiziurn brunneum Petch （indigenous strain） against sawfly in the laboratory. Larvae treated with either fungus in the laboratory died faster than control larvae and displayed 49.4%-68.4% mycosis. In the field, B. bassiana density remained high in the week after application, during larval descent to the soil. Fungal density decreased to 25% at 49 d after application and to 0.4% after 55 weeks. Molecular markers revealed that the majority of fungal isolates recovered comprised the applied B. bassiana strain GHA. Larvae pupating in soil cages in the orchard for 49 d displayed 17% mycosis. The high efficacy under laboratory conditions was not seen in the field. B. bassiana application resulted in densities above the upper natural background level during the growing season, but reversion to background levels occurred within a year. It remains to be investigated whether this has a detrimental effect on nontarget organisms. Additional work is needed to bridge the knowledge gap between laboratory and field efficacy in orchards.

Response of small rodents to manipulations of vegetation height in agro-ecosystems

Some small mammal populations require human interference to conserve rare or threatened species or to minimizeadverse effects in plant production. Without a thorough understanding about how small rodents behave in theirenvironment and consideration of how they react to management efforts, management will not be optimal. Socialbehavior, spatial and temporal activity patterns, predator avoidance and other behavioral responses can affect pestrodent management. Some of these behavioral patterns and their causes have been well studied. However, theirimpact on pest rodent management, especially for novel management approaches, is not always clear. Habitatmanipulation occurs necessarily through land use and intentionally to reduce shelter and food availability and toincrease predation pressure on rodents. Rodents often respond to decreased vegetation height with reducedmovements and increased risk sensitivity in their feeding behavior. This seems to result mainly from an elevatedperceived predation risk. Behavioral responses may lessen the efficacy of the management because the desiredeffects of predators might be mediated. It remains largely unknown to what extent such responses can compensateat the population level for the expected consequences of habitat manipulation and how population size and cropdamage are affected. It is advantageous to understand how target and non-target species react to habitatmanipulation to maximize the management effects by appropriate techniques, timing and spatial scale withoutcausing unwanted effects at the system level.

Influence of nozzle enabling strategy on spray deposition of crop protection unmanned aerial system

Proper nozzles arrangement is significant to improve spray deposition of crop protection unmanned aerial system(UAS).Besides fuselage structure,the control strategy is another nozzle location changing method when there are multiple sets of nozzles.A four-rotor crop protection UAS equipped with four centrifugal nozzles was used to conduct a field experiment in the rupturing stage of rice.Two sets of nozzles in the front and rear of the fuselage were enabled independently to investigate spray deposition,including spray coverage and droplet density on the sampling cards.Various nozzle rotating speeds and flight speeds were employed in the experiment to study the influence of nozzle location on the deposition.With different nozzle rotating speeds,the droplet spectrum could be controlled.The results show that the average coverage and average cumulative droplet density are negatively correlated with flight speed.Average droplet density is also negatively correlated with the droplet size.Spray deposition of front nozzles is significantly reduced compared with that of the rear nozzles under the same spray parameters,especially when the droplet size is too large or the flight speed is too fast.The reduction is mainly concentrated in the center area of the spray swath.As a result,the average cumulative droplet density of the front nozzles decreases by 25.96%in total.The average droplet density decreases by 18.54%when the droplet size is smaller than 100μm,decreases by 25.02%when between 100μm and 200μm,and decreases by more than half when larger than 200μm.This research can provide guidance for the installation of UAS nozzles and spray control strategy design.

Parameters optimization of crop protection UAS based on the first industry standard of China

The effective swath width(ESW)and the droplet penetration rate(DPR)directly affect the spraying quality,the spraying efficiency and the control effect of pests and diseases during the crop protection unmanned aircraft system(CPUAS)application.However,the ESW and DPR are not constant with the changes of the flight speed(FS)and the flight height(FH).In order to investigate the ESW and DPR of the CPUAS P20,four levels of FS(3 m/s,4 m/s,5 m/s and 6 m/s)and three levels of FH(1.5 m,2.0 m and 2.5 m)experiments were carried out according to the first industry standard of China for the CPUAS in the wheat field.The results demonstrated that the ESWs were negatively correlated with the FS and the FH.Most of the ESWs were over 2 m in the 12 treatments,in which the maximum one was 3.25 m(3 m/s,1.5 m).The DPRs were negatively correlated with the FH under the same FS,the average value of the DPRs was 48.37%,in which the maximum one was 78.34%(4 m/s,1.5 m)and the minimum one was 25.5%(6.0 m/s,2.5 m).The statistical analyses showed that the FS had significant impacts on the ESWs(0.01<p-value<0.05)while there were no significant differences among different FH treatments(p-value>0.05).The impacts of both FS and FH on the DPRs were extremely significant(p-value<0.01),and the interactive impacts were significant(0.01<p-value<0.05).Therefore,it is concluded that reducing the FS could increase the ESWs,and reducing the FH could increase the DRPs at the same FS.In conclusion,the maximum spraying efficiency of P20 was 4.342 hm2/h with 6 m/s FS and 1.5 m FH in case of satisfying the requirement of DPRs.This study provided scientific references for guiding the CPUAS spraying.

Novel obstacle-avoiding path planning for crop protection UAV using optimized Dubins curve

In recent years,the crop protection unmanned aerial vehicle(UAV)has been raised great attention around the world due to the advantages of more efficient operation and lower requirement of special landing airport.However,there are few researches on obstacle-avoiding path planning for crop protection UAV.In this study,an improved Dubins curve algorithm was proposed for path planning with multiple obstacle constraints.First,according to the flight parameters of UAV and the types of obstacles in the field,the obstacle circle model and the small obstacle model were established.Second,after selecting the appropriate Dubins curve to generate the obstacle-avoiding path for multiple obstacles,the genetic algorithm(GA)was used to search the optimal obstacle-avoiding path.Third,for turning in the path planning,a strategy considering the size of the spray width and the UAV’s minimum turning radius was presented,which could decrease the speed change times.The results showed that the proposed algorithm can decrease the area of overlap and skip to 205.1%,while the path length increased by only 1.6%in comparison with the traditional Dubins obstacle-avoiding algorithm under the same conditions.With the increase of obstacle radius,the area of overlap and skip reduced effectively with no significant increase in path length.Therefore,the algorithm can efficiently improve the validity of path planning with multiple obstacle constraints and ensure the safety of flight.

Design and experiment of a hydraulic lifting wind field test platform for crop protection UAS

As a new type of crop protection machine,the crop protection unmanned aerial system(CPUAS)is developing rapidly in China.The wind field generated by the rotor has a great influence on the deposition and penetration of spraying droplets.The purpose of this study was to develop a reliable and stable test platform that could be used for wind field test of CPUAS,and to carry out the downwash experiments on the platform to obtain the downwash distribution law of a CPUAS Z-3N(100 kg level,Nanjing Research Institute on Simulation Technique,Nanjing,China).The tests showed that the performances of the developed platform could meet the expected design requirements.The platform operated stably and reliably during the downwash experiments of Z-3N,which indicated it could be applied for CPUASs of 100 kg level and below.The vibration characteristics of the platform with different heights(2.0 m,3.0 m,5.0 m,7.0 m,10.0 m)were obtained through modal analysis,which could effectively guide avoiding the resonance for stable and reliable operation during the experiments with the tested CPUAS Z-3N.A ring-radial method was designed combined with the platform for the downwash measurement.The experimental results showed that the downwash distribution of Z-3N was not symmetrical;the downwash wind speed decreased with the increase of the radial distance while the changing trend was not consistent as the height increased.Moreover,the area with high wind speed was mainly within 3.0 m of the radial distance,and the maximum value was 11.37 m/s.The study provided a new way for wind field test of CPUASs and would provide some references for better utilization of wind field during the CPUAS spraying.

Spectral response of spider mite infested cotton:Mite density and miticide rate study

Two-spotted spider mites are important pests in many agricultural systems.Spider mites(Acari:Tetranychidae)have been found to cause economic damage in corn,cotton,and sorghum.Adult glass vial bioassays indicate that Temprano™(abamectin)is the most toxic technical miticide for adult two-spotted spider mite.From an aerial application standpoint,additional research is needed to identify aerial application parameters for this miticide.The objective of this study was to investigate spectral response of spider mite-infested cotton plants with different density levels of mites and treated with different rates of miticide.Results showed significantly different spectral signatures of cotton plants infested with different density levels of mites.By treating mite-infested cotton plants with five different Temprano rate treatments(control,one-eighth,one-fourth,one-half,and full rates),spectral reflectance curves were found to be significantly different.Four wavelengths of 550 nm,560 nm,680 nm and 740 nm were important for detecting the spectral differences among mite infested cotton plants treated with various rate of Temprano.Normalized Difference Vegetative Index imagery was able to detect different levels of cotton plant damage.Half-rate application of Temprano controlled mite-infested plants as effectively as the full-rate application.These findings may lead to reduced cost and quantity of miticides used to maintain effective crop production and protection.