Occurrence Regularity and Comprehensive Prevention and Control Techniques of Sunflower Downy Mildew

This paper examines the occurrence regularity and comprehensive prevention and control techniques for sunflower downy mildew.It provides a detailed discussion of the pathogens,symptoms,and associated risks,as well as the transmission pathways,underlying causes,and prevention and control techniques related to sunflower downy mildew.The aim is to offer valuable references and technical guidance for the effective management of this disease.

Occurrence and Control of Main Pest Groups in Allium tuberosum Fields in Shijiazhuang

[Objectives]This study was conducted to investigate the species and occurrence patterns of main pests in the Chinese chive(Allium tuberosum)fields in Shijiazhuang.[Methods]Our research group conducted a systematic investigation on the types and occurrence of major pests in Chinese chive fields in Shijiazhuang from April 2019 to November 2020 using the Malaise net method.[Results]The main pests harming Chinese chives in the region included Thrips tabaci,Bradysia odoriphaga,Luperomorpha suturalis,Acrolepla alliella,Liriomyza chinensis,and Neotoxoptera formosana.The pest populations in the region mainly experienced two peak periods,from mid June to mid July and from late August to late September.Meanwhile,corresponding green prevention and control measures were proposed based on the occurrence characteristics and biological characteristics of different pests in local chive fields.[Conclusions]Predicting the occurrence of pests in Chinese chive fields can provide basis for farmers to take timely prevention and control measures,reduce the damage of pests in the field to Chinese chives and realize high-quality production of Chinese chive.

Occurrence Factors and Efficient Green Prevention and Control Technology of Peanut Stem Rot Caused by Sclerotium rolfsii in Southern Mountainous Area of Shandong Province

Peanut stem rot caused by Sclerotium rolfsii is a soil-borne disease,and it has become the main disease of peanut in Yimeng mountainous area.S.rolfsii survives the winter as mycelia and sclerotia in soil and debris,becoming the primary source of infection in the following year.The disease resistance of peanut varieties,high temperature and humidity,and cultivation measures are the pathogenic factors affecting the occurrence of peanut stem rot.The disease can be effectively controlled by screening disease-resistant varieties and seed chemical treatment,improving soil by deep tillage and crop rotation,carrying out flowing water management of affected field,cutting off transmission routes,and strengthening seed dressing and triple spraying control.

Occurrence Regularity and Control Research of Apple Early Defoliation Disease in West Sichuan Plateau

[ Objective ] The research aimed to discuss the occurrence regularity of apple early defoliation disease and control effects of fungicides in west Sichuan plateau. [ Method ] Apple early defoliation disease in west Sichuan plateau was systematically investigated during 2009 and 2011, and the control effects of different fungicides during different spraying periods were studied. [ Result] The species of pathogen mainly was Marssonina ma/i （ P. Henn）, accounting for 32.5%, Phyl-losticta Pirina Sa accounted for 29.9%, and Alternaria mali Roberts accounted for 25.7%. The field fluctuation regularity was as follows ： the disease generally be- gan in the mid-May and ended in early and middle October with only one damage peak during the whole year, the fluctuation had positive correlation with rainfall （ R2 =0.891 8 ＊ ＊ ）. Control test showed that 40% flusilazole had the best control effect （86.5%）, which was best to apply after anthesis. [ Conclusion ] The paper provided theoretical basis for the effective control against apple early defoliation disease.

Species and Occurrence of Scarab in Sweet Potato Growing Areas of Xuzhou,Jiangsu

Frequency-vibrancy pest-killing lamp was used to calculate the numbers and types of scarabs during the growing period of sweet potato in Xuzhou area, thus to study the occurrence regularity of scarab and effect of meteorological factor on its occurrence, which provided a reference and guidance for the control of grub in sweet potato field. The monitoring results indicated that scarabs in sweet potato planting area of Xuzhou mainly included Anomala corpulenta, Holotrichia parallela Motschulsky, Maladera verticalis and Holotrichia trichophora Fairm. Holotrichia tri- chophora Fairm has entered into its late stage at the early cultivation stage of sweet potato with a few occurrence quantities. The elongation stage of sweet potato vine is the full incidence period of imagoes of Maladera verticalis and Anomala cor- pulenta. Full incidence period of Holotrichia parallela Motschulsky is from late June to middle August, the outbreak cycle of which is long. The unearthed imagoes fol- low the regular change ＂many-few-many-few＂. Effects of meteorological factor on the activities of various scarabs are different. The activities of various scarabs are fre- quent in warm and windless sunny days. In rainy days, Holotrichia parallela Motschulsky, Holotrichia trichophora Fairm and Maladera verticalis are inactive. The numbers of Anomala corpulenta in cloudy days but not rainy days are higher than that in sunny days.

Integrated Prevention and Control Technology for Coffee Leaf Rust in Yunnan Province

This paper investigates the damage symptoms and occurrence regularity related to coffee leaf rust,and proposes a comprehensive prevention and control strategy grounded in the principle of prioritizing prevention and implementing integrated prevention and control.This strategy encompasses the cultivation of rust-resistant varieties,the implementation of agricultural practices,the application of chemical interventions,the utilization of hyperparasitic fungi,and the protection and utilization of natural enemies.The paper further outlines the necessary requirements for effective prevention and control,emphasizing the importance of enhancing responsibility implementation,fostering systematic prevention and control measures,enhancing guidance services,and increasing publicity and guidance.The aim is to offer technical guidance for the integrated prevention and control of coffee leaf rust in Yunnan Province.

Coupling mechanism of THM fields and SLG phases during the gas extraction process and its application in numerical analysis of gas occurrence regularity and effective extraction radius

The analysis of the coupling mechanism of thermal-hydraulic-mechanical(THM)fields,and solid-liquidgas(SLG)phases during gas extraction process is of profound significance to explore its numerical application in the gas occurrence regularity and its effective extraction radius.In this study,the Hudi coal mine in Qinshui basin is taken as the research area,the influencing factors of gas occurrence were analyzed,the differences in overburden load for gas pressure distribution and the factors influencing the effective extraction radius were further discussed by using the COMSOL software.The results show that the derivation of mathematical model in gas extraction shows that the process is a process the THM fields restrict each other,and the SLG phases influence each other.The longer the extraction time,the larger the influencing range of borehole,and the better the extraction effect.The larger the diameter of borehole,the larger the effective extraction radius,and the influence on gas extraction effect is smaller in the early stage and larger in the late stage.The borehole arrangement should be flexibly arranged according to the actual extraction situation.The higher the porosity,the higher the permeability,the better the gas extraction effect.The larger the overburden load of reservoir,the stronger the effective stress,which will result in the more severe the strain,and the closure of pore and fracture,which in turn will lead to the decrease of permeability and slow down the gas extraction.The relationship among extraction time,borehole diameter,negative pressure of gas extraction,permeability with effective extraction radius is exponential.This study has important theoretical and practical significance for clarifying and summarizing the gas occurrence regularity and its engineering practice.

Occurrence Reasons and Control Measures of Caligula Japonica in Longnan City of China

Caligula Japonica has continuously broken out in large scale in Longnan City, Gansu Province of China, causing heavy economic losses. In order to ef- fectively control the insect and to increase the production benefit of walnut in Longnan, the authors have investigated and observed the morphological characters and living habits of C. Japonica. The major causes of continuous large-scale occurrence of C. Japonica in Longnan City are analyzed concretely, and the integrated con- trol measures are put forward from the aspects of silvicultural measures, physical control, chemical control and biological control.

Occurrence Regularity and Control of Thrips on Leek

[Objective] The paper was to clear the species and occurrence regularity of thrips severely occurred in leek field, and to study the main control methods. [Methods] The species of thrips on leek were identified in Sichuan Province, and the damage symptoms, occurrence regularity and control methods of thrips in leek field were studied. [Result] The morphological characteristic of thrips on leek was Frankliniella occidentalis(Pergande). ITS molecular identification results showed that the amplified fragment was 520 bp, which shared the similarity of 99.81% with the base se-quence of F. occidentalis. F. occidentalis concentrated at the height of 80 cm from the ground; in sunny days, the occurrence frequency of F. occidentalis was relatively high during 15:00 and 17:00; rainwater had obvious lethal effect on F. occidentalis, and the lethal rate was 29.30%. Field trial showed that 20% dinotefuran SG and 40% acetamiprid GR had good control effect against F. occidentalis. The control effect of 20% dinotefuran SG 1 500 times dilution was the best, up to 92.56%. [Conclusion] The results will provide effective technical support for large-scale control of thrips in leek field.

Occurrence Regularity of Myzus persicae and Aphid- transmitted Virus Disease in Zhenyuan County of Guizhou

[ Objective] The paper provided a reference for establishment of effective prevention mechanism against aphids in Zhenyuan tobacco area. [ Melllod ] The initial population quantity of aphids in early spring, migration of winged aphids, occurrence regularity and damage status of Myzus persicae and aphid-transmit- ted virus （PVY ＋ CMV） were investigated in Zhenyuan County from 2014 to 2015 using 10-point checkerboard sampling method, yellow dish trapping method and 5-point sampling method. [ Result] The total amount of aphids in Brassica campestris was the largest among overwintering hosts, with an average of 18.44 speci- men/plant. The migration of winged aphids presented bimedal pattern; the population dynamics of wingless aphids presented unimodal pattern, and the occurrence peak was from May to June. [ Conclusion] Field control against M. persicae in tobacco fields should be conducted from mid May to early June.

Occurrence Regularity and Mating Rhythm of Overwintering Adults of Tessaratoma papillosa on Longan Tree

[ Objeodve ] The occurrence regularity and mating rhythm of overwintering adults of Tessaratoma papiUosa on longan tree were studied in the paper, so as to provide scientific reference for effective prevention and control against the pest. [Method] During the mating period of overwintering adults of T. papillosa, mating duration, occurrence regularity and mating rhythm of overwintefing adults within g8 h as well as their occurrence and mating status during April and June were observed. [Result] Mating duration of T. pap///osa adults for$ -9 h accounted for 18.2%, and duration for 10 -ll h and more than 13 h accounted for 54.5% and 27.3%, respectively. According to daily observation, the maximum adult quantity of T. papillosa adults appeared at 9：00 am, followed by 13：00 pm. There were two peaks （9：00 am and 15：00 pm） and troughs （6：00 am and 19：00 pro） for adult quantity of T. papiUosa and its mating pairs within 24 h as times changed. Mating pairs were positively correlated with observed adult quantity. Adult quantity and mating pairs increased since April 1, and reached the maximum value on April 6. Afterwards, they were gradually dropped down, and almost no adults of T. papiUosa were found after June 11. [Conclusion] The mating peak of T. papillosa adults was from April to May, and there were two mating peaks （9：00 am and 13：00 pm） and troughs （6：00 am and 19：00 pm） every day. Adults repeatedly mated and spawned, while mating usually lasted for 10 -11 h either during the daytime or at night.

Occurrence Regularity and Prevention and Control Technology of Kiwifruit Root Rot

Kiwifruit root rot is an important root disease of kiwifruit, which has occurred increasingly in recent years. The disease leads to the death of whole kiwifruit plant under severe condition, and has become an important disease restricting kiwi fruit industry development. The characteris-tics, occurrence, etiology and symptoms of kiwifruit root rot were introduced in the paper, and the prevention and control technology against the dis-ease were put forward from the aspects of agriculture, biology and chemistry.

Occurrence Regularity of Tobacco Cutworm Moth (Spodoptera Litura) in Low-Altitude Tobacco Cultivation Areas in Lincang

[ Objective ] The paper was to study the occurrence and damage regularity of tobacco cutworm moth （Spodoptera Litura Fabricius） in low-altitude area in Lincang city. [ Method] The adult sex attractant monitoring, field investigation of occurrence and damage, and observation of continuous generation development of natural populations were carried out in natural flue-cured tobacco fields. [ Result] In field growth period of flue-cured tobacco under low-altitude of 1 000 - 1300 m, tobacco cutworm moth occurred for 4 generations, the duration of each generation was about 33 d, and the main injurious generation was the third generation. [ Conclusion] The paper provided reference for comprehensive control of tobacco cutworm moth in the low altitude areas.

Preliminary Report on Species and Occurrence Regularity of Diseases,Pests and Weeds of Corn in Angola

[ Objective] The paper was to understand species of diseases, pests and weeds and their occurrence periods and dynamic changes of quantity during corn growing period in rainy and dry seasons in Angola. [ Method] Using systematic investigation method, the species and occurrence regularity of diseases, pests and weeds of corn in Pedras Negras farm （ Malanje）, Sanza Pombo farm （Uige） and Catete farm （Luanda） in the Mrican continent, the Republic of Angola, were studied in two dry seasons and a rainy season from 2011 to 2012. [ Result] The occurrence status of pests and diseases of corn during dry and rainy seasons were basically similar, and only individual diseases and pests had different incidence degrees. The corn varieties from the United States and Brazil had prominent advan- tages in resistance to diseases and barren. Due to different climate environments in dry and rainy seasons, the unearthed rate of weeds in fields was also different. Soil moisture had great impact on weed population and density. Soil layer depth greatly influenced unearthed speed and unearthed rate of weeds. [ Conclusion ] The study cleared species, occurrence period and harmful levels of pests, diseases and weeds of corn in three provinces of Angola.

Occurrence Regularity and Prediction Model of Underground Pest Adults in Hangzhou District of China

To improve forecasting and sustained control level of underground pests, trapping quantity of underground pests （black cutworm,mole cricket and scar-ab） by lamps and their field dynamics in Hangzhou district from 2005 to 2011 were investigated in the paper. The results showed that different pests had obvious differences in population dynamic. The black cutworm （Agrotis ypsilon） had several damage peaks （late May, late June and late July） and the moth amount in early period was relatively high. The mole cricket （ Gryllotalpa africana） had two damage peaks （late May to early July, early September to mid and late October）. The scarab （Anomala corpulenta） had one damage peak （late May to late June）. There were periodic changes in total quantity of underground pests among years, and the peak period appeared in the year of 2005, 2007 to 2009 and 2011, respectively. On this basis, temperature, humidity, rainfall and light were used as forecas- ting factors, using the method of stepwise regression, 19 factors with significant correlation were screened out and prediction models for occurrence quantity and oc- currence period of the three pests were established. By using accuracy degree judge model for verification, the score values of prediction model for occurrence quan-tity and occurrence period of the three underground pests were more than 58 and 70, which indicated that the historical coincident rate and prediction accuracy of estabhshed prediction models were good.

Occurrence Regularity and Control of Tobacco Mosaic Virus (TMV) in Wuxi Tobacco Area of China in 2011

On the basis of general situation and new characteristics of tobacco mosaic virus （TMV） in Wuxi tobacco area in 2011, the paper expounded the objec-tive reasons of TMV via systemic investigation, field experiment and date sorting. Meanwhile, combined with mcteorological conditions and results of systemic inves-tigation, the study especially analyzed meteorological conditions, outbreak and prevalence regularity of TMV and control efficacy of chemical reagents against TMV. The results showed that climatic conditions were the main conditions affecting TMV. There were three occurrence peaks of TMV in 2011, as a result of meteorologi-cal conditions of the months from April to June. The peaks were concerned with a wide range of rainfall about half a month before, low temperature, high humidity and scant sunshine and temperature jump after rain. The results of control effects showed that the chemical reagents could obviously prevent TMV, but once tobacco plants were infected, spraying chemical reagents would not have effective control effect against TMV.

Occurrence Regularity of Major Damage Generations of Nilaparvata lugens(Stl) in Single Cropping Medium Rice Region in Sandu County of Guizhou Province

In order to clarify occurrence regularity of major damage generations of Nilaparvata lugens( Stl) in Sandu Shui Autonomous County( Sandu County for short),Guizhou Province,a karst single cropping medium rice region,the population dynamics of N. lugens were systematically studied using the methods of light trap and systematic field survey from 2009 to 2011. The results showed that the number of immigration generations caught by light trap and the actual population of N. lugens in fields were different among three years. The daily maximum trapping numbers of N. lugens amounted to 6 688 in 2009,which were 15. 3 and 2. 5 times of that in 2010 and 2011,respectively. The peak numbers in prediction nursery were 10 777,4 630 and 1 615 heads per hundred hills in 2009,2010 and 2011,respectively. The forth and fifth generations of N. lugens were the major damage generations in single cropping medium rice fields,and the initial immigration day was significantly related with primary-peak day. The occurrence degree of adults and nymphs of N. lugens varied with years and transplanting periods,and the peak days of N. lugens nymphs were from late July to early August in 2010 and 2011. The occurrence peaks of adults and nymphs in late transplanting paddy field were later than that in the early one. Meanwhile,the coexisted various growth periods of rice,due to time differences of transplanting,were conducive to inhabitation and reproduction of N. lugens. The population dynamics of spiders and Cyrtohinus lividipennis well synchronied with that of N. lugens,but predatory capacity of spiders and C. lividipennis was not enough to control N. lugens.

Occurrence Regularity of Fruit Physiological Disease Spongy Tissue in Zihua Mango(Mangifera indica L.)

[ Objective ] The aim was to study the occurrence regularity of fruit physiological disease spongy tissue in Zihua mango （Mangifera indica L. ）. [ Meth. od] Main features of disease symptoms of Zihua mango fruit spongy tissue were investigated from 2002 to 2005 ,and the correlation between the incidence of Zihua mango fruit spongy tissue and its external factors （ fruit maturity, fruit size and fruit yield per plant） was analyzed comprehensively. [Result] The main features of disease symptoms appeared depressed cavity in the middle or lower part of fruit, forming spongy-like cavity. Immature fruits basically had no incidence. The dis- ease began to appear before 10 d of maturity. The disease incidence rate had extremely positive correlation with fruit weight, fruit vertical diameter or cross diame- ter. [ Conclusion] The research provides reference for field diagnoses, identification, preharvest and postharvest uninjurous test of fruit physiological disease suonaw tissue.

Occurrence Characteristics and Control of Thrips tabaci in Yanji City

With the increasing plant area of welsh onion, onion and Chinese onion, the damage of Thrips tabaci in Yanji City is aggravating day by day. Through preliminary investigation and literature reading, we summarized occurrence status, morphological characteristics, damage characteristics, occurrence regularity, living habit, outbreak cause and integrated control technology of T. tabaci in Yanji City, in order to control the hazard of T. tabaci effectively.

Occurrence Regularity and Integrated Control Technique of Grubs in Peanut Producing Areas of Linyi City

In order to effectively control the harm of grubs in peanut field, Linyi Comprehensive Experimental Station of Shandong Peanut Industry Research System conducted an investigation and study on the occurrence regularity and control techniques of peanut grubs, and summarized the occurrence regularity and causes of the outbreak of grubs in peanut field. Moreover, effective and sustainable control measures are proposed.