Geostatistical Analysis of Spatial Distribution and Dynamics of Dead Heart of Sugarcane Seedlings Caused by Borer

Dead heart of sugarcane is an important symptom caused by borer attack. In the present study, the spatial distribution and dynamics of dead heart of sugarcane in the field were investigated based on geostatistical analysis, and semivariograms were computed in four separate directions(0°, 45°, 90° and 135°) and fitted with various theoretical models to determine the best fitted one. The Ordinary Kriging was used to interpolate spatial data. The results revealed that the density of dead hearts of sugarcane increased in a single-peak pattern, and the degree of spatial aggregation and random variation both decreased with the increase in the density of dead heart. In addition, dead heart of sugarcane caused by borer exhibited spatial aggregation.With the increase in the density of dead heart, the degree of spatial aggregation decreased, while the correlation increased. Kriging interpolation indicated that the correlation between the spatial patches was weak in early seedling stage, and became strong in middle and late seedling stage.

Occurrence and Epidemic Dynamics and Accurate Prevention and Control of Important Sugarcane Pests and Diseases in the Sugarcane Areas of Yunnan

Based on investigation and research, according to the current actual production of sugarcane, the occurrence dynamics and outbreak causes of important pests and diseases that seriously affect sugarcane production were summarized, and accurate and efficient green prevention and control technology was put forward according to the occurrence and damage characteristics of important pests and diseases, such as strengthening sugarcane introduction and quarantine, breeding and selecting varieties resistant to diseases and pests, promoting the use of detoxified healthy seedlings vigorously, applying lamp trapping technology on a large scale, scientifically guiding and promoting biological prevention and control technology, practically promoting the precise and efficient application of slow-release long- acting and low toxic pesticides, strengthening field management, spraying pesticides in time at the early stage of a disease, and doing a good job of monitoring and emergency prevention and control of sudden pests.

Research Progress and Prospect of Sugarcane Smut

Sugarcane smut disease( Ustilago scitaminea Sydow) is an important fungal disease worldwide,which seriously affects yield and quality of sugarcane and threatens the stability and development of sugarcane industry. This paper reviewed disease occurrence,damage,pathogen,symptoms,genetic diversity and detection methods of sugarcane smut,response of sugarcane to sugarcane smut stress and control measures of sugarcane smut. The in-depth research of sugarcane smut was also prospected,aiming to provide theoretical reference and scientific basis for the effective control of sugarcane smut.

Control Effect of Slow-release, Long-acting and Multi-functional New Pesticides on Sugarcane Borders and Woolly Aphids

In order to select the long-acting,low toxic,low-risk and multi-functional new pesticides for the control of sugarcane borders and woolly aphids and precise and efficient application technology,the control effect of 10% monosultap · thiamethoxam granular formulation and 1% Bt · clothianidin granular formulation on sugarcane borders and woolly aphids were studied.The results showed that 10% monosultap·thiamethoxam GR and 1% Bt·clothianidin GR had good control effects on sugarcane borders and woolly aphids.They were ideal slow-release,long-acting,low toxic and multi-functional new pesticides used to control sugarcane borders and woolly aphids.They could be used alternately with other pesticides to delay the emergence and development of pest resistance to pesticides.The best dosage of the two pesticides in the field was 45 kg/hm^2.They could be mixed with fertilizer( 1200-1800 kg/hm^2),scattered in sugarcane ditches or at the base of sugarcane plants,and covered with soil or film from January to July.The control effect on dead heart seedlings damaged by borers could be up to above 79.2%,and the control effect on sugarcane woolly aphids could reach more than 98.8%.In comparison with the control group,the actual yield and sugar content of sugarcane increased by above 41 555 kg/hm^2 and 6.5% respectively.The application of slow-release,long-acting,strong systemic and multi-functional new agents with fertilizer around roots is convenient,precise and efficient,labor-saving,time-saving and environmentally friendly,and is worthy of being widely applied in sugarcane areas.

Control Effects of a New Sex Pheromone Trap and Biological Agents on Sesamia inferens Walker and Argyroploce schistaceana (Snellen)

This study was conducted to explore and seek high-efficiency and safe green control techniques on sugarcane borers,promote green control of diseases and pests of sugarcane and build a resource-conserving,environmentally friendly and sustainable governance system of diseases and pests of sugarcane.A new sex pheromone trap of sugarcane borers,abamectin· Bacillus thuringiensis (Bt) and tebufenozide were selected and applied in field trials.The use of the new sex pheromone trap of sugarcane borers (6 traps/hm 2) in combination with 0.05% abamectin·10 billion active gemmae/g B.thuringiensis (Bt) WP (1.8 kg/hm 2) or new sex pheromone trap of sugarcane borers (6 traps/hm 2) in combination with 200 g/L tebufenozide SC (1.5 L/hm 2) were the best in the sugarcane production.New sex pheromone trap of sugarcane borers should be installed in early march,and biological agents were mixed with water 900 kg per hectare and sprayed evenly sugarcane plants at the beginning of April.Their control effects of dead heart rate and bored stalk rate could be more than 69.98% and 49.09%,respectively,which were superior to that of the control pesticide 3.6% bisultap GR (90 kg/hm 2).The results showed that new sex pheromone trap of sugarcane borers in combination with abamectin· B.thuringiensis (Bt) or tebufenozide was the optimum mode of green control techniques on sugarcane borers.When it was alternately or coordinately used with other technology,it could delay the emergence and development of drug resistance,and it was worthy of widespread popularization and application in sugarcane area.

Dynamic Monitoring and Control Measures of Spodoptera frugiperda(J.E.Smmith) in Low Latitude Plateau Sugarcane Areas

Spodoptera frugiperda (J.E.Smmith) is one of the major migratory pests warned by the Food and Agriculture Organization (FAO).It has been successfully invaded sugarcane and corn in Jinggu,Longchuan,Gengma,Menghai,Yingjiang,Lancang of Yunan Province,China.In view of the great variety of hosts,wide range of habitats and strong migration ability,S.frugiperda has the potential of causing catastrophic threats to sugarcane production.In this paper,we made a systematic introduction to the morphological and biological characteristics of S.frugiperda,analyzed its occurrence situations and occurrence trends in Yunnan of China and other countries around the world,and proposed the control strategies and measures of ecological regulation and control,natural enemies protection and utilization,biological control,pesticide control and adults trapping based on the outbreak characteristics of S.frugiperda and the actual sugarcane production in low latitude plateau areas.

Integration and Application of Comprehensive Prevention and Control Technology for Sugarcane Borers in Low Latitude Plateau of China

Aimed at the difficult problem of prevention and control of disastrous sugarcane borers in low latitude plateau of China,this research systematically overcame the bottleneck of comprehensive prevention and control of sugarcane bores after 10 years of collaborative research,and formed a number of core product technologies,which promoted the green and high-quality development of the sugarcane industry and achieved the following innovative results.In this study,the species,population structure and damage characteristics of disastrous sugarcane borers in low latitude plateau were clarified for the first time,which provided a scientific basis for the formulation of technology and application of comprehensive prevention and control.The monitoring technology system and early warning monitoring network were constructed for the monitoring of borer population in low latitude plateau sugarcane area,which realized the accurate monitoring of the population dynamics of sugarcane bores and provided technical support for comprehensive prevention and control.The flight spraying technology by unmanned aerial vehicle(UAV)was developed for bores in the low latitude plateau cane area,and it has been successfully applied in a large area,thereby opening up a new way of light,simple and efficient for effective control of borers.The scale application of lamp trapping and sexual attracting to kill adult insects technology promoted the advancement of green control technology of bores.Integration was made to the comprehensive control techniques like UAV flight control,biological agents,physical and chemical inducement and control,and sexual attractant trapping in the low latitude plateau sugarcane area,and standardized technical regulations have been formulated,which significantly improved the overall prevention and control effect of large areas.The technologies for the comprehensive prevention and control of sugarcane borers have been popularized and applied in 8 major sugarcane producing states(cities)in low altitude plateau of Yunnan over the years,which has controlled the damage and showed remarkable control effect.In 2017-2018,the integrated control technology was popularized and applied to a total of 2.78×10^5 hm^2(1.33×10^4 hm^2 of UAV flight control)of area,which recovered a total of 3.666×10^6 t of sugarcane losses,increasing 4.69×10^5 t of sugar with the sales increase of 3.979 billion yuan,added profits of 1.251 billion yuan and the taxes increase of 188 million yuan.The research results show that the technology has high technical integration,strong practicability,high degree of transformation,significant economic,social and ecological benefits,which provide technical supports for the sustainable development,loss reduction and efficiency increase of the sugarcane industry in the low-latitude plateau sugarcane region,and make significant contributions to the economic development of ethnic minorities in the border-stricken areas and the increase of farmers income and poverty alleviation.

Research on Variation of Sugarcane Red Rot (Colletotrichum falcatum Went) and Sugarcane Disease Resistance

Sugarcane red rot caused by Colletotrichum falcatum Went is one of the important fungal diseases causing significant losses to sugarcane production,commonly known as "cancer" of sugarcane.It has risen from a minor disease to a major disease,resulting in the death of sugarcane in Lincang,Menglian and Shiping sugarcane areas in Yunnan Province.Due to the frequent variation of this pathogen,it is difficult to control,the pesticide control effect is not ideal at present,and there is still no effective and radical cure measures.The research on the variation of C.falcatum and sugarcane disease resistance is the only way to achieve the sustainable control of sugarcane disease.This paper mainly reviewed the genetic variation on the morphological,pathogenic and molecular variation of C.falcatum,and rapid molecular detection methods,and sugarcane disease resistance research in combination with the latest research at home and abroad.An outlook for further research on sugarcane red rot in the future was also given,to provide a theoretical basis for the research and control of sugarcane red rot in China.

Occurrence Dynamics and Control of 6 Sugarcane Pests with Potential Threats

In recent years,with the adjustment of agricultural structure,the change of planting system,the continuous cropping phenomenon and the abnormal climate and environment have provided favorable conditions for the spread,reproduction and survival of sugarcane pests.The pest species that are harmful to sugarcane have increased,which pose potential threats to sugar cane production.Therefore,the occurrence dynamics and control of 6 sugarcane pests with potential threats were studied in order to prospectively grasp the dynamics of sugarcane pests,scientifically and effectively prevent and control sugarcane pests,and ensure the safety of sugarcane production.

Propagation properties of radially polarized Pearcey–Gauss vortex beams in free space

We investigate a family of radially polarized Pearcey–Gauss vortex beams(RPPGVBs),obtain the general propagation expressions of an RPPGVB,and study the intensity distribution,phase pattern,spin currents as well as the orbital currents when the RPPGVB propagates in free space.The focal plane and the intensity of the focal point can be adjusted by changing the position of the vortex and the scaling factors.We also investigate how the waist size influences the propagation properties.

Molecular Techniques for Detection of Major Diseases in Sugarcane

It is necessary to rapidly diagnose diseases, identify and monitor the pathogens to achieve scientific and effective control of major diseases in sugarcane. In the present study, the molecular techniques for rapid detection of 13 pathogens that cause 10 important diseases of sugarcane including smut, rust, leaf scald, ratoon stunting, red stripe, mosaic, Fiji, yellow leaf, white leaf and bacilliform virus were established by Sugarcane Research Institute, Yunnan Academy of Agricul- tural Sciences after years of effort. The results will provide scientific basis for effective diagnosis and control of sugarcane diseases, detection of virus-free seedlings and quarantine management of exotic species.

The Epidemic Characteristics and Control Strategies of Sugarcane Red Rot

Sugarcane red rot caused by Colletotrichum falcatum Went. is an important epidemical fungal disease. The outbreak of large-scale epidemics would cause huge losses to sugarcane production. At present,the pesticide control effect is not ideal. Moreover,due to long-term continuous cropping and changeable climate in recent years,favorable conditions for the occurrence of red rot have been created. The disease was often prevalent in various sugarcane areas,caused serious damage and seriously affected the sugarcane production. With the rapid spread of the disease worldwide,the control of sugarcane red rot has become the hot spot in the field of sugarcane production and research. In this paper,the epidemic characteristics of sugarcane red rot were analyzed in combination with the field investigation. To provide theoretical basis for prevention and control of red rot in China and effective control the widespread occurrence of the disease,combined with the latest research results at home and abroad,we proposed to select resistant varieties mainly,use biological control agents such as Trichoderma spp.,Pseudomonas spp.and Bacillus spp. to treat the seed cane and soil,timely apply chemical pesticide in critical periods and strengthen scientific and effective comprehensive coordinated prevention and control measures such as field management against red rot.

Dominant Natural Enemies of Sugarcane Pests and Their Protection and Utilization in Yunnan

This paper discussed and summarized the parasitic characters and the protection and utilization of 7 species of dominant natural enemies of sugarcane pests in Yunnan, China. Sugarcane pests are numerous and there are rich natural enemy resources in Yunnan sugarcane areas. There are more than 283 species of natural enemies against sugarcane pests in Yunnan, among which the dominant natural enemies with protection and utilization value and research significance include Trichogramma, Apanteles flavipes(Cameron) and Sturmiopsis inferens Townsend parasitic on sugarcane borers, Synonycha grandis(Thunberg), Lemnia biplagiata(Swartz), Chilomenes sexmaculata(Fabricius) and Thiallela sp catching and feeding on Ceratovacuna lanigera Zehntner, and Euborellia pallipes Shiraki preying on Saccharicocus sacchari(Cocherell), Dysmicoccus bohinsis Kuw, Trochorhopalus humeralis Chevrolat and Diocalandra sp. There is also one fungal parasite, namely Beauveria bassiana, which is widely distributed in nature, and can parasitize in a variety of sugarcane pests including sugarcane borers, Exolontha serrulata(Gyllenhal), Alissonotum impressicolle Arrow, T. humeralis and Otidognathus rubriceps Chevrola. It has a natural parasitism rate generally around 10% and certain natural inhibition effect on sugarcane pests. Reasonably protecting and utilizing natural enemies and giving full play to the natural regulation of natural enemies on pests are of great significance for protecting the ecological environment, maintaining the ecological balance of sugarcane fields, improving the comprehensive management level of pests, and promoting the sustainable development of sugar industry.

The Occurrence,Damage and Control Strategies of Sugarcane Borers in Yunnan

Sugarcane borers are the most common pests in Yunnan sugarcane areas,and their harm is the most serious presently. The damage caused by sugarcane borers has become the first important factor seriously influencing the sustainable and stable development of sugar industry in Yunnan. To scientifically and effectively prevent and control sugarcane borers to ensure the production safety of sugarcane,the characteristics of occurrence and damage of sugarcane borers in Yunnan sugarcane areas were systematically introduced,and corresponding comprehensive control measures and strategies were proposed according to the characteristics of its occurrence and damage and the actual production of sugarcane.

Digital light processing 3D printing for microfluidic chips with enhanced resolution via dosing-and zoning-controlled vat photopolymerization

Conventional manufacturing techniques to fabricate microfluidic chips,such as soft lithography and hot embossing process,have limitations that include difficulty in preparing multiple-layered structures,cost-and labor-consuming fabrication process,and low productivity.Digital light processing(DLP)technology has recently emerged as a costefficient microfabrication approach for the 3D printing of microfluidic chips;however,the fabrication resolution for microchannels is still limited to sub-100 microns at best.Here,we developed an innovative DLP printing strategy for high resolution and scalable microchannel fabrication by dosing-and zoning-controlled vat photopolymerization(DZC-VPP).Specifically,we proposed a modified mathematical model to precisely predict the accumulated UV irradiance for resin photopolymerization,thereby providing guidance for the fabrication of microchannels with enhanced resolution.By fine-tuning the printing parameters,including optical irradiance,exposure time,projection region,and step distance,we can precisely tailor the penetration irradiance stemming from the photopolymerization of the neighboring resin layers,thereby preventing channel blockage due to UV overexposure or compromised bonding stability owing to insufficient resin curing.Remarkably,this strategy can allow the preparation of microchannels with cross-sectional dimensions of 20μm×20μm using a commercial printer with a pixel size of 10μm×10μm;this is significantly higher resolution than previous reports.In addition,this method can enable the scalable and biocompatible fabrication of microfluidic drop-maker units that can be used for cell encapsulation.In general,the current DZC-VPP method can enable major advances in precise and scalable microchannel fabrication and represents a significant step forward for widespread applications of microfluidics-based techniques in biomedical fields.