Fractional Gradient Descent RBFNN for Active Fault-Tolerant Control of Plant Protection UAVs

With the increasing prevalence of high-order systems in engineering applications, these systems often exhibitsignificant disturbances and can be challenging to model accurately. As a result, the active disturbance rejectioncontroller (ADRC) has been widely applied in various fields. However, in controlling plant protection unmannedaerial vehicles (UAVs), which are typically large and subject to significant disturbances, load disturbances andthe possibility of multiple actuator faults during pesticide spraying pose significant challenges. To address theseissues, this paper proposes a novel fault-tolerant control method that combines a radial basis function neuralnetwork (RBFNN) with a second-order ADRC and leverages a fractional gradient descent (FGD) algorithm.We integrate the plant protection UAV model’s uncertain parameters, load disturbance parameters, and actuatorfault parameters and utilize the RBFNN for system parameter identification. The resulting ADRC exhibits loaddisturbance suppression and fault tolerance capabilities, and our proposed active fault-tolerant control law hasLyapunov stability implications. Experimental results obtained using a multi-rotor fault-tolerant test platformdemonstrate that the proposed method outperforms other control strategies regarding load disturbance suppressionand fault-tolerant performance.

Root structure of slope protection plants in a high-grade highway

Root length and root length density of Lespedeza bicolor,Amorpha fruticosa,and Sea buckthorn were investigated in a country highway-TongSan highway（Tongjiang to Sanya） in Heilongjiang Province,China.The root lengths were divided into five root orders according to Pregizter sequence classification method.Results show that sea buckthorn roots are dominated by coarse roots in the horizontal growth,while L.bicolor has a large proportion of fine roots in vertical conical growth and A.fruticosa is in depth growth.Root length density of L.bicolor in all the root sequences is higher than that of sea buckthorn and A.fruticosa.On the basis of the root structure,it is inferred that L.bicolor roots mainly absorb the surface soil moisture for its normal growth;in contrast,A.fruticosa has good uptake ability to deep soil water.The root structure of sea buckthorn implies that it has a strong drought resistance.

The Register and Characteristics of Chinese Key Protected Wild Plants in Dabie Mountains National Nature Preserve, Hubei Province

A study was conducted on the newly promulgated key protected wild plants distributed in the Dabie Mountains National Nature Reserve in Hubei in 2021.According to statistics,Dabie Mountains National Nature Reserve of Hubei Province has a total of 41 species of wild plants under national key protection,including 7 species in the first class and 34 species in the second class.Among them,6 are cultivated species,4 in the first class,and 2 species in the second class.The characteristics of Chinese key protected wild plants in the Dabie Mountains National Nature Reserve in Hubei Province were analyzed.

Impact of Implementing 1991 Act of the International Convention for the Protection of New Varieties of Plants in China

The Union for the Protection of New Varieties of Plants is abbreviated as UPOV. The Convention for the Protection of New Varieties of Plants has 1961/1972 Act ,1978 Act and 1991 Act. China is member of UPOV and its regulations of protection of new varieties of plants conform to 1978 Act. At present, there is big debate whether China accedes to 1991 Act. This paper mainly discussed advantages and possibilities that China accedes to 1991 Act, and concluded that it is highly desirable that China should consider acceding to 1991 Act in order to contribute to development of system on protection of new varieties of plants.

Review of Studies on Rare Earth against Plant Disease

Agricultural application of rare earth (RE) has been generalized for several decades, and it is involved in crops, vegetables and stock raising in China. However, all the researches on RE mainly focus on the fields such as plant physiological activity, physiological and biochemical mechanism, sanitation toxicology and environmental security. Plant protection by using RE and the induced resistance of plant against diseases were summarized. The mechanism of rare earth against plant disease is highlighted, which includes following two aspects. First, RE elements can control some phytopathogen directly and reduce its virulence to host plant. Another possibility is that RE elements can affect host plant and induce the plant to produce some resistance to disease.

Orchid conservation in China from 2000 to 2020:Achievements and perspectives

We review achievements in the conservation of orchid diversity in China over the last 21 years.We provide updated information on orchid biodiversity and suggestions for orchid conservation in China.We outline national policies of biodiversity conservation,especially of orchid conservation,which provide general guidelines for orchid conservation in China.There are now approximately 1708 known species of Orchidaceae in 181 genera in China,including five new genera and 365 new species described over the last 21 years.The assessment of risk of extinction of all 1502 known native orchid species in China in 2013 indicated that 653 species were identified as threatened,132 species were treated as data-deficient,and four species endemic to China were classified as extinct.Approximately 1100 species(ca.65%)are protected in national nature reserves,and another~66 species in provincial nature reserves.About 800 native orchid species have living collections in major botanical gardens.The pollination biology of 74 native orchid species and the genetic diversity and spatial genetic structure of 29 orchid species have been investigated at a local scale and/or across species distributions.The mycorrhizal fungal community composition has been investigated in many genera,such as Bletilla,Coelogyne,Cymbidium,Cypripedium,and Dendrobium.Approximately 292 species will be included in the list of national key protected wild plants this year.Two major tasks for near future include in situ conservation and monitoring population dynamics of endangered species.

Preparation of the UPOV Guidelines for the Conduct of Tests for Distinctness, Uniformity and Stability–Tea Plant [Camellia sinensis (L.) O. Kuntze]

Distinctness, Uniformity and Stability （DUS） testing is the technical base of Plant Variety Protection （PVP） and the scientific basis for the approval of Plant Breeder＇s Rights （PBR）. DUS Test Guidelines are not only the technical manuals for the DUS testing authorities to conduct the testing, but also the technical standards for the competent authorities to examine the DUS of new varieties of plants. Tea plant, originated from Yunnan Province, China, is a very important woody cash species in the world. The International Union for the Protection of New Varieties of Plants （UPOV） DUS Test Guidelines for tea plant is the first Test Guidelines prepared by China for the UPOV. In this article, the subject, selection, and determination of characteristics, states of expression of characteristics and the selection of example varieties, assessment of the UPOV DUS Test Guidelines for tea plant were elucidated in detail. Finally, the proposal of PVP for tea plant in China was also proposed. The preparation of UPOV DUS Test Guidelines for tea plant will have important significance both for promoting the development of PVP and increasing the status of international PVP fields for China.

Plant Variety Protection and DUS Testing Technique

DUS testing technique used for plant variety protection was reviewed in the paper, and some suggestions were made on how to establish the appropriate technology system in China. Meanwhile, the potential exploitation of the technique was discussed.

thylenediurea(EDU)effects on Japanese larch:an one growing season experiment with simulated regenerating communities and a four growing season application to individual saplings

Japanese larch(Larix kaempferi(Lamb.)Carr.)and its hybrid are economically important coniferous trees widely grown in the Northern Hemisphere.Ground-level ozone(O_(3))concentrations have increased since the preindustrial era,and research projects showed that Japanese larch is susceptible to elevated O_(3)exposures.Therefore,methodologies are needed to(1)protect Japanese larch against O_(3)damage and(2)conduct biomonitoring of O_(3)in Japanese larch forests and,thus,monitor O_(3)risks to Japanese larch.For the first time,this study evaluates whether the synthetic chemical ethylenediurea(EDU)can protect Japanese larch against O_(3)damage,in two independent experiments.In the first experiment,seedling communities,simulating natural regeneration,were treated with EDU(0,100,200,and 400 mg L^(-1))and exposed to either ambient or elevated O_(3)in a growing season.In the second experiment,individually-grown saplings were treated with EDU(0,200 and 400 mg L-1)and exposed to ambient O_(3)in two growing seasons and to elevated O_(3)in the succeeding two growing seasons.The two experiments revealed that EDU concentrations of 200-400 mg L^(-1)could protect Japanese larch seedling communities and individual saplings against O_(3)-induced inhibition of growth and productivity.However,EDU concentrations≤200 mg L^(-1)did offer only partial protection when seedling communities were coping with higher level of O_(3)-induced stress,and only 400 mg EDU L^(-1)fully protected communities under higher stress.Therefore,we conclude that among the concentrations tested the concentration offering maximum protection to Japanese larch plants under high competition and O_(3)-induced stress is that of 400 mg EDU L^(-1).The results of this study can provide a valuable resource of information for applied forestry in an O_(3)-polluted world.

Ethylenediurea(EDU)effects on hybrid larch saplings exposed to ambient or elevated ozone over three growing seasons

Ground-level ozone(O_(3))pollution is a persistent environmental issue that can lead to adverse effects on trees and wood production,thus indicating a need for forestry interventions to mediate O_(3) effects.We treated hybrid larch(Larix gmelinii var.japonica×L.kaempferi)saplings grown in nutrient-poor soils with 0 or 400 mg L^(-1) water solutions of the antiozonant ethylenediurea(EDU0,EDU400)and exposed them to ambient O_(3)(AOZ;08:00-18:00≈30 nmol mol^(-1)) or elevated O_(3)(EOZ;08:00-18:00≈60 nmol mol^(-1))over three growing seasons.We found that EDU400 protected saplings against most effects of EOZ,which included extensive visible foliar injury,premature senescence,decreased photosynthetic pigment contents and altered balance between pigments,suppressed gas exchange and biomass production,and impaired leaf litter decay.While EOZ had limited effects on plant growth(suppressed stem diameter),it decreased the total number of buds per plant,an effect that was not observed in the first growing season.These results indicate that responses to EOZ might have implications to plant competitiveness,in the long term,as a result of decreased potential for vegetative growth.However,when buds were standardized per unit of branches biomass,EOZ significantly increased the number of buds per unit of biomass,suggesting a potentially increased investment to bud development,in an effort to enhance growth potential and competitiveness in the next growing season.EDU400 minimized most of these effects of EOZ,significantly enhancing plant health under O_(3)-induced stress.The effect of EDU was attributed mainly to a biochemical mode of action.Therefore,hybrid larch,which is superior to its parents,can be significantly improved by EDU under long-term elevated O_(3) exposure,providing a perspective for enhancing afforestation practices.

Research progress of plant antimicrobial peptides

Plant antimicrobial peptides are a very large family of antimicrobial peptides,which have strong resistance to various pathogenic microorganisms,especially fungi.With the increasing use of antibiotics,the problems caused by antibiotics,including antibiotic residues and pathogen resistance,are becoming more and more prominent.The research on antimicrobial peptides as new antibiotic substitutes is also a hot spot.This article introduces the action sites and antibacterial mechanisms of several plant antimicrobial peptides,as well as the application of plant antimicrobial peptides in the fields of medicine,agriculture,and food preservation.

Influence of seven levels of chemical/biostimulator protection on amino acid profile and yield traits in wheat

Biostimulators combined with pesticides can reduce the need for chemical crop protection to yield healthy wheat with high grain quality and nutritional value.The goal of this four-year field study was an assessment of the effects of seven levels of sulfonylurea herbicide,morpholine and triazole fungicides,and humic biostimulator protection on concentrations of 20 amino acids(AAs)and on yield parameters under diverse climatic conditions.Application of pesticides and biostimulators reduced amino acid concentrations.Sulfonylurea applied alone reduced AAs least.Chemical(herbicide+fungicide)protection or its combination with humic biostimulator were the most effective strategies for increasing yield,thousand-kernel weight,spike number,grain surface area,and wet gluten.Reduced dosages of fungicides showed effects on AA content and crop parameter values similar to those of the recommended dosages of fungicides and are in line with the European Commission’s “From Farm to Fork”strategy.Humic biostimulators as agents supporting pesticide protection should be optimized for wheat growth stage to achieve the most desirable wheat parameters and implemented in agricultural practice.

Ethylenediurea(EDU)spray effects on willows(Salix sachalinensis F.Schmid)grown in ambient or ozone-enriched air:implications for renewable biomass production

Ground-level ozone(O_(3)) is a widespread air pollutant causing extensive injuries in plants.However,its effects on perennial energy crops remain poorly under-stood due to technical difficulties in cultivating fast-growing shrubs for biomass production under O_(3) treatment on the field.Here we present the results of a two-year evaluation in the framework of which willow(Salix sachalinensis F.Schmid)shrubs were exposed to ambient(AOZ)or elevated(EOZ)O_(3) in two successive growing seasons(2014,2015)and treated with 0(EDU0)or 400 mg L^(−1)(EDU400)eth-ylenediurea spray in the second growing season.In 2014,EOZ altered the chemical composition of both top young and fallen leaves,and a novel mechanism of decreasing Mg in fallen leaves while highly enriching it in young top leaves was revealed in shrubs exposed to EOZ.In 2015,EDU400 alleviated EOZ-induced decreases in leaf fresh mass to dry mass ratio(FM/DM)and leaf mass per area(LMA).While EDU400 protected against EOZ-induced suppression of the maximum rate at which leaves can fix carbon(A_(max))in O_(3)-asymptomatic leaves,it did not alle-viate EOZ-induced suppression of the maximum rates of carboxylation(VCmax)and electron transport(J_(max))and chlorophylls a,b,and a+b in the same type of leaves.In O_(3)-symptomatic leaves,however,EDU400 alleviated EOZ-induced suppression of chlorophylls a and a+b,indicating different mode of action of EDU between O_(3)-asymptomatic and O_(3)-symptomatic leaves.Extensive herbivory occurred only in AOZ-exposed plants,leading to suppressed biomass production,while EOZ also led to a similar suppression of biomass production(EDU0×EOZ vs.EDU400×EOZ).In 2016,carry-over effects were also evaluated following cropping and transplantation into new ambient plots.Effects of EOZ in the preceding growing seasons extended to the third growing season in the form of suppressed ratoon biomass production,indicating carry-over effect of EOZ.Although EDU400 protected against EOZ-induced suppression of biomass production when applied in 2015,there was no carry-over effect of EDU in the absence of EDU treatment in 2016.The results of this study provide novel mechanistic understandings of O_(3)and EDU modes of action and can enlighten cultivation of willow as energy crop.

Correlation Analysis of Energy Consumption of Agricultural Rotorcraft

With the rapid development of unmanned aerial vehicle technology,unmanned aerial vehicles(UAVs)have been widely used in the field of agricultural plant protection.Compared with fuel-driven UAVs,electrically driven rotorcrafts have many advantages such as lower cost,simpler operation,good maneuverability and cleaner power,which them popular in the plant protection.However,electrical rotorcrafts still face battery problems in actual operation,which limits its working time and application.Aiming at this issue,this paper studied the influence of rotorcraft flight parameters on energy consumption through series of carefully designed flight experiments.First of all,the linear motion experiments have been designed that the rotorcraft was made to perform speed tests and acceleration test with the speed varied from 2∼9 m/s.Secondly,the turning maneuver experiments are carried out under the different circular routes,a rotorcraft was made to conduct successive steering maneuvers at a certain speed of 2 m/s.With the collected tests data,the relation of the energy consumption and the flight dynamic parameter are analyzed through correlation analysis,and the test results of different pairs of experiments have been compared.The research results of this paper would encourage the agricultural rotorcraft to make less maneuvers during operation,which can also provide practical experience and data support for subsequent optimization of flight parameters and reduction of energy consumption.

Particle Kinematics Analysis of Droplet Drift in Spraying Operation of Plant Protection UAV

[Objectives]The paper was to study the effect of droplet drift on spray quality of plant protection UAV.[Methods]Based on the theory of multiphase flow and the method of particle kinematics,the force and motion trajectory of droplet sprayed by plant protection UAV were theoretically analyzed and mathematically modeled.On the basis of the assumption of wind speed in the ground layer and the laminar sublayer,that is,it is assumed that the wind speed in the area of wind measurement was approximately a linear distribution,the coupling iterative solution of the equations was carried out.The influence of droplet diameter,flight height,flight speed of plant protection UAV,course angle,wind speed,wind direction,initial droplet velocity and direction of initial velocity on droplet drift were analyzed.The influence of the coupling effect of each factor on droplet drift was further discussed and the distribution of droplet drift concentration was obtained.[Results]The wind speed and direction had much influence on the drift distance of droplets,and the drift distance and the initial velocity angle show a quadratic function distribution.Under the given conditions,the drift distance was the closest when the initial velocity angle was about 20°.The droplet drift was mainly distributed scatteredly around the nozzle.[Conclusions]The study provides a reference for improving the spraying quality of plant protection UAV.

Contrast Test of Precision Electric Mist Duster and Electric Sprayer

[Objectives]The paper was to compare and verify the operation performance of precision electric mist duster and electric sprayer,and to select the optimum plant protection equipment suitable for greenhouse application.[Methods]Agents were sprayed by precision electric mist duster and electric sprayer to control tomato downy mildew in greenhouse,and the control effect and pesticide utilization rate were compared.[Results]Compared with electric sprayer,precision electric mist duster improved the pesticide utilization rate by 31.7%,improved the spray efficiency by 20 times,and increased the control effect by 13.2%.[Conclusions]The study provides technical support for the popularization and application of precision electric mist duster in greenhouse and other facilities cultivation.

Design and Research of Efficient Adaptive Spray Plant Protection UAV

When the plant protection UAV is spraying on plants, the operator usually performs visual inspection on the vertical distance between the UAV and the plant to adjust the spray height to complete the application. Visual inspection by human eyes is easy to cause the error of spray deposition and deposition density. In order to improve the full utilization of drugs and the spraying efficiency of plant protection UAV, an efficient adaptive spray plant protection UAV was designed, and the vertical distance from the UAV to the plant was collected by ultrasonic wave. Meantime, the plant density was detected in real time, and the flight attitude of plant protection UAV and application rate of spray nozzle were automatically adjusted. The experimental results showed that the designed highly efficient adaptive spray plant protection UAV had fast response speed, precise spray location and less drug loss.

Application of MR Technology in Teaching:A Case Study of UAV Agriculture&Forestry Plant Protection Curriculum

In order to solve the problems of insufficient training equipment,relatively lack of curriculum resources and single teaching means in the teaching of UAV(unmanned aerial vehicle)applied technology major,this paper studies the application of MR(Mixed Reality)in UAV applied technology major teaching,with the teaching of UAV agriculture&forestry plant protection curriculum as the carrier.The study will solve the pain points in teaching,improve the teaching ability and teaching information level,and increase the talent training quality of UAV,agriculture&forestry plant protection and related majors.Furthermore,it will create a protective,interactive,remote and scalable teaching experience for stu-dents,which can improve the teaching effect and reduce the teaching cost.

Thoughts on Science and Technology Service in Agricultural Research Institutes:Taking Institute of Plant Protection of Hebei Academy of Agricultural and Forestry Sciences as an Example

Scientific and technological services are necessary for strengthening agriculture.Under the new situation,agricultural research institutes should give full play to their advantages,strive to innovate scientific and technological services methods,and improve scientific and technological service levels.Combined with the practice of science and technology work of Institute of Plant Protection of Hebei Academy of Agricultural and Forestry Sciences,this paper made an in-depth analysis on the present situations and existing problems in the scientific and technological services of agricultural research institutes.Based on the analysis,it came up with recommendations including change ideological concepts,strengthening service awareness,adhering to people-oriented principle,enhancing the team building,improving mechanism construction,stimulating innovative vitality,exploring service methods,and enriching service connotation,so as to improve scientific and technological service works.

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