Chunhua TANG, Hejun ZHANG
Abstract In view of the fact that pine wood nematode disease is the most dominant disease in Pinus massoniana forests， which has the characteristics of strong infectivity， fast transmission speed， and great difficulty in prevention and control， a brief description was made to the occurrence status of pine wood nematode disease and difficulties faced with its control in the State-owned Sishibacao Forest Farm of Yunyang County， China， followed by the analysis on the prevention and control measures from aspects of strict control， epidemic situation monitoring， joint prevention and control， and clearance of infected trees， as well as the existing problems of pine wood nematode disease. Finally， reasonable suggestions including strengthening the construction of talent team were put forward， aiming to provide a beneficial reference for the scientific， efficient， and reasonable control of pine wood nematode disease in Pinus massoniana Lamb. forests of Yunyang State-owned Sishibacao Forest Farm.
Key words Pine wood nematode disease; Occurrence status; Control measures
Received：
December 8， 2022 Accepted：
February 9， 2023
Chunhua TANG （1982-）， female， P. R. China， devoted to research on forestry afforestation project management， forest disease and insect pest control.
*Corresponding author.
Bursaphelenchus xylophophilus belongs to the genus Bursaphelenchus of Aphelenchoididae in Aphelenchida of Nematoda in Nemathelminthes. It is a major pest that damages the pine forest ecosystem， as well as one of the most harmful invasive alien species in China. Infected pine trees have yellowish brown or reddish brown needles， and the entire trees wither and die， eventually decaying， making it extremely difficult to control.
The disease caused by B. xylophophilus is called pine wood nematode disease， which is a common parasitic disease type in Pinus massoniana forests and a relatively harmful pest disease among current parasitic diseases［1-3］. It is also a devastating epidemic， also known as wilt disease of P. massoniana， which has a direct impact on the growth status of P. massoniana， even causing death of P. massoniana. It is a devastating infectious disease of P. massoniana， as well as the most dangerous forestry pest in the world， with its origin in North America. Pine wood nematode disease is highly infectious. Once infected with the disease for about 40 d， P. massoniana trees die. Currently， there is no effective drug to treat it， so it is known as the "cancer" of P. massoniana. If effective measures are not taken， the entire area can die within 3-5 years， so it is also known as the "bird flu" of P. massoniana. The disease is extremely destructive and belongs to a major ecological disaster in China.
The main tree species of the State-owned Sishibacao Forest Farm in Yunyang County （hereinafter referred to as the forest farm） is P. massoniana， which is affected to varying degrees by pine wood nematode disease every year. If not prevented and controlled in a timely manner， it will seriously affect the security of forest resources， which will not only affects forest ecology， but also affects the economic development of the entire Yunyang and surrounding counties. For the forest farm， as a first-line grassroots unit， it is an important forest management and protection measure to do a good job in pest control.
Occurrence Status of Pine Wood Nematode Disease
Basic situation of the occurrence area
The forest farm is located in Renhe Street and Bayang Town， Yunyang County， Chongqing City， in the eastern part of the Sichuan Basin. It is located on the north bank of the Yangtze River and the Tiefeng Mountain extension in the Daba Mountains northwest of Yunyang County. It reaches 49 km up to Wanzhou District and 20 km down to Yunyang County， with a geographical location of 108° 35′01″-108°39′53″ east longitude and 30° 58′57″-31°01′14″ northern latitude. The entire forest farm is in a long strip shape， with a width of about 3 500 m from the north to the south， and a length of about 30 500 m from the east to the west， with a total area of 23 333 hm2. P. massoniana accounts for about 90% of the forest vegetation. The forest farm has a complex terrain， significant differences in elevation， uneven distribution of water and heat， and a large vertical difference in climate. It has a humid monsoon climate in the mid-subtropical zone， characterized by significant monsoons， mild climate， and abundant water and heat.
Within the forest farm， there are four management organizations：
the office， the planning and finance office， the forest prevention office， and the asset protection office. There are three management and protection stations， namely， Mazhanggou， Dabao， and Changcao. Currently， there are 19 employees， including 10 professional and technical personnel， and 2 management personnel.
Occurrence status of pine wood nematode disease
Epidemic situation
The forest farm covers a total area of 2 333 3 hm2， with 349 sub-compartments. P. massoniana forests account for about 90% of the forest vegetation. In 2020， 72 sub-compartments were infected with pine wood nematode disease， with an infected wood area of about 819.4 hm2 of infected trees， involving 2 220 dead trees， and 1 020 trees broken by wind. In 2021， nearly 69 sub-compartments were infected with pine wood nematode disease， with an infected wood area of about 817 hm2， involving 1 830 dead trees， 1 120 broken trees.
In 2021， the number of sub-compartments suffering from the epidemic in 2021 decreased by 3 compared with 2020， and the area decreased by 2.73 hm2. The number of diseased and dead trees decreased by 390， and the number of broken trees （dead， wind-broken trees， landslides， etc.） increased by 100， an increase of 6% compared with the previous year.
The terrain in the forest area of the forest farm is complex and steep. In addition， natural factors such as strong winds and heavy snow caused by extreme weather led to the increase of many dead trees. In 2020 and 2021， the number of wind-broken trees was， respectively， 1 020 and 1 120， accounting for 31% and 37% of the total number of infected trees， respectively. Wind-broken trees increased the amount of prevention and control， so the control effect was not particularly significant.
Difficulties in the treatment of pine wood nematode disease
The steep terrain increases the difficulty of prevention and control
The difficulty in the process of epidemic wood removal and control has increased， and the removal and control in mountain farms cannot be completed thoroughly. With the spread of the epidemic， the disease has eroded from sparse forest areas in low mountains and valleys to dense forests in middle mountains. The control of the disease faces steeper mountain landforms， making the operation more difficult. The forest farm is located in high mountains and valleys， with cliffs. There are 349 sub-compartment in the forest area of the Sishibacao forest farm， involving 82 sub-compartments with steep slopes， accounting for 23% of the sub-compartments， covering an area of 278.36 hm2， 102 sub-compartments with cliffs， accounting for 29% of the sub-compartments， covering an area of 494.79 hm2， accounting for 21% of the total area， and 151 sub-compartments having a slope （danger）， accounting for 43% of the sub-compartments， covering an area of 1 515.6 hm2， accounting for 65% of the total area. Therefore， the removal and control operation is very difficult.
Difficulty in epidemic blockade
As an important port and tourist city in the Yangtze River Basin， Yunyang County has undergone large-scale infrastructure construction， resulting in frequent flow of goods and personnel. The Shanghai-Chengdu Expressway traverses the entire Yunyang County， increasing the possibility of pine wood nematode disease being introduced from other epidemic areas and counties， and increasing the difficulty of prevention and control.
Wanzhou District and Kaizhou District， adjacent to Yunyang County， also belong to the pine wood nematode disease epidemic area. There are three management and protection stations （Dabao management and protection station， Changcao management and protection station， and Mazhanggou management and protection station） in the Sishibacao Forest Farm. Dibaliang and Dadiping in the Changcao forest area are adjacent to Songbai Village， Xiongjia Town， Wanzhou District， and Lujiagou in the Changcao forest area is adjacent to Jian Village （Tiefeng Mountain） in Kaizhou District， increasing the risk of infection in the epidemic area.
Natural disasters lead to more wind-broken trees
Extreme weather often occurs in mountainous areas within Yunyang County， and wind disasters， landslides and engineering damage have caused a large number of P. massoniana to break and collapse in forests， increasing the difficulty of prevention and control work. Wind-fallen trees account for 30% of the total number of trees removed.
Prevention and Control Measures of Pine Wood Nematode Disease
Strict control and assigning responsibilities to the people
First， the municipal and county governments and forestry competent departments having a strong control force provide full support for funds and policies for eradication work. Yunyang Forestry Bureau comprehensively controls state-owned forest farms and professional eradication teams， implements prevention and control responsibilities， and supervises the entire process. Yunyang Forestry Bureau conducts technical training on eradication， strictly controls the quality of eradication， and strictly implements rewards and punishments. A special eradication leading group and a special eradication group have been established， and they issue an annual implementation plan for pine wood nematode disease prevention and control every year. Second， socialized and professional services for prevention and control work are actively promoted. The participation of professional enterprises in governance， process supervision and inspection and acceptance is comprehensively promoted through the full process of agency by a third-party professional organization， making the evaluation of governance results relatively objective and fair. Third， the forest farm has established a pine wood nematode eradication leading group and formulated a pine wood nematode disease control plan， improved the responsibility system of "leading group-management and protection station-forest ranger"， and assigned the responsibility to nine forest rangers in the three management and protection stations.
Epidemic monitoring
First， forest rangers visit and monitor the forest farm. Strengthening the monitoring and early detection of infected trees is the key to the prevention， control， and treatment of pine wood nematode disease. Forest rangers take responsibility for epidemic monitoring， and the "monthly report ledger" monitoring and reporting system is implemented from the horizontal to the side， vertical to the bottom， with full coverage， and no dead angles. Second， intermediary organizations are employed to organize and implement special general surveys in spring and autumn， regularly investigate the areas where pine wood nematode disease occurs in the entire farm， monitor the full coverage of pine forests under the jurisdiction， sample and detect each occurrence class， and keep records. They implement the three correspondences of actual occurrence， sub-compartment schedule， and sub-compartment map. They strictly strengthen the monitoring of non-epidemic areas and epidemic areas， as well as areas adjacent to epidemic areas， so as to resolutely eliminate the occurrence of "blind spots and dead angles" in monitoring. Dead P. massoniana trees are found， and verified for the cause of death， and the number and location of deaths are accurately counted. For newly discovered epidemic spots， they should be detected， eradicated and eliminated in the same year.
Traps for killing M. alternatus
The forest farm gets 120 sets of traps from the forest protection station of the forestry bureau of the county around mid April every year and hangs them in three forest areas， including 40 sets in the Mazhanggou forest area， 50 sets in the Dabao forest area， and 30 sets in the Changcao forest area. They are hung in open and well ventilated areas in forests， with a distance of no less than 2 m from the ground. The inducing cores are replaced once a month， as detailed in the inducing core replacement schedule. The replaced old inducing core should not be discarded at will， and should be sealed and recycled in plastic bags in a timely manner. The plastic bags should be handed over to forest prevention station of the county for centralized processing to avoid affecting the trapping effect and causing artificial transmission of the epidemic.
Chunhua TANG et al. Control of Bursaphelenchus xylophilus in the State-owned Sishibacao Forest Farm of Yunyang County， China
Elimination of diseased trees
Cleaning up infected trees （selective logging） is currently the main method of forest management in forest farms. In forests affected by the epidemic， manual logging and cleaning are carried out from September to March of the following year （before the emergence period of M. alternatus）.
Quarantine treatment of dead P. massoniana
Crushing treatment
According to the actual situation of the forest farm， in order to reduce the pressure of eradication， resolve the conflicts between forestry and farmers and reduce the cost of eradication， dead P. massoniana cut down are transported to the vicinity of the highway for crushing treatment， due to the proximity of Dabao Management and Protection Station to the highway.
Centralized burning treatment
Mazhanggou Management and Protection Station and Changcao Management and Protection Station have steep mountains， long transportation distances， and the crushing costs are thus high. The infected trees are destroyed by burning. All dead and infected trees， as well as residual branches， that have been felled， are transported from the forests to an open area 100 m away from the edge of the forests. They will be supervised by a specially-assigned person on site and burned in a centralized manner， following the principle of only walking away after the fire is extinguished to avoid causing forest fires.
Treatment technology for stumps of diseased trees
For infected trees， they are cut by saws according to technical specifications， and the height of stumps left should not exceed 5 cm. Each stump needs to be peeled. For dead P. massoniana stumps and live tree stumps that have M. alternatus holes， small pits of 5 cm×5 cm are chiseled using tools or pulled out using an electric saw. Two pieces of aluminum phosphide （3-4 pieces for piles with a diameter of more than 20 cm） are placed on each stump， which is also covered with a plastic film with a thickness of more than 0.8 mm， and the mouth of the bag is bound with a plastic bag or fine iron wire， and buried with soil.
Cleaning of diseased trees outside the forest area
The firewood of residents around the forest area is regularly inspected at least 3 times a year， and pine wood infected with nematodes is not allowed to be used as firewood. At the same time as carrying out centralized treatment in mountain areas， the forest farm registers and records households， logging enterprises and leisure villas within and around the forest area， conducts self-inspections， and cleans up any hidden diseased trees in households. The cleaning scope should include areas where infected trees are easily hidden， such as farmers livestock barns， and hillsides， gullies， and caves near farmers houses， and farmers， logging enterprises and leisure villas that have repeatedly hidden infected trees should be persuaded， otherwise they will be transferred to the forestry law enforcement team for handling.
Existing problems
As of November 2022， the prevention and control of pine wood nematode disease in the forest farm achieved certain results compared with 2021 with the joint efforts of superior leaders and all employees. However， the prevention and control situation is still severe， mainly due to the following issues：
Lack of professional technical strength
Firstly， there is a shortage of professional and technical personnel， as well as inadequate existing staff， and non-forestry professionals are more， causing amateur forestry management， poor effectiveness， and low efficiency. Secondly， there is a lack of professional eradication efforts. Due to the steep terrain and complex terrain in the forest farm area， the distribution area of disease and death is over 667 hm2， and the eradicated individuals are over 3 000 plants and scattered， making the task of eradication heavy. At present， the aging population in China is getting large， and a large number of people are transferring to cities， especially young and middle-aged people， who mostly settle down in cities. The personnel involved in the eradication of infected trees are mostly elderly farmers in the surrounding forest areas， which cannot meet the needs of the removal work.
Promotion of prevention and control needs to be strengthened
Artificial transmission is the main reason for the spread of pine wood nematode disease in China. According to statistics， nearly 80% of areas with pine wood nematode disease epidemic in China are caused by the influx of infected wood and its products［2］. The forest farm mainly promotes the harm of pine wood nematode disease through promotional slogans， leaflets， oral propaganda， and other means. During the prevention and control of pine wood nematode disease， it is common for farmers to hide infected trees in their homes， and their understanding of the harm of pine wood nematode disease is insufficient.
The treatment method for diseased trees is single
The forest farm mainly monitors the disease through manual removal of infected trees and traps. The terrain of the forest land in the forest farm is complex， with steep slopes and wide areas. In addition， there is a lack of manpower， making it difficult to isolate the infection. The forests are quickly re-infected after being treated， and the work of treatment is endless. Thus， artificial treatment is quite difficult.
Regional joint defense and control are not enough
There are problems in the border area between the forest farm and the township， as well as in the flower arrangement area， that is to say， the eradication operation always does not cover all these areas， leading to prominent issues such as inadequate treatment and clearance of the pine wood nematode epidemic， and cross infection. It is another significant factor in the endless work of governance.
Work suggestions
The forest farm has implemented strict control measures such as epidemic monitoring， regional joint prevention and control， and clearance of infected trees to prevent and control the occurrence of pine wood nematodes in small groups and surrounding areas， which has played a positive role in the spread of pine wood nematode disease and achieved phased results. However， due to external factors such as wind， snow， and landslides， the eradication work still faces a severe situation. In order to further improve the prevention and control of pine wood nematode disease in Sishibacao Forest Farm， following work suggestions are proposed：
Strengthening the construction of talent team
Introducing talented people
One is to introduce high-quality and high-level talents and optimize the knowledge and ability structure of management personnel， in order to address the need for special talents in the development of the forest farm industry. The second is to comprehensively improve employees educational level of through adult education.
Conducting professional technical training
Based on the situation of pine wood nematode disease in the forest farm， a plan should be formulated to ensure sufficient personnel for treatment. It is necessary to regularly organize professional teams and invite experts， to provide training to the eradication team and improve employees forestry technical level through professional training. Focusing on the construction of competitiveness， we can cultivate a team of outstanding forestry production and management talents who understand business and have high professional literacy and strong market awareness. The existing talent team structure can be optimized to provide talent protection for the development of forest farms and promote the sound and rapid development of the forest farm industry.
Purchasing social services
Relevant departments can recruit multiple veterans from social labor dispatch companies for forest resource management and protection， purchase social insurance， fire prevention equipment， fuel receipts and pickup trucks for them， and let them stay at the forest farms Dabao management and protection station year-round. They mainly carry out forest fire prevention and extinguishing work from March to September each year and pine nematode control work from October to March， and assist in completing other tasks assigned by the forest farm during the rest of the time.
Strengthening infrastructure construction and enhancing prevention and control capabilities
Strengthening infrastructure construction
We will strive for project funds to meet the needs for fire roads， biological barriers， transfer processing sites， etc. A large number of standardized and constructed roads in forest areas are planned for small cranes and crushers to enter the site for operation. Hoists transfer infected trees to open areas and use crushers to crush them， solving the problem of single manual removal of infected trees. Mechanized removal in a large quantity is efficient and environmentally friendly.
Improving comprehensive prevention and control capabilities
A sound monitoring and early warning system should be established. The infrastructure for forest farm-management and protection station-management and protection personnel regular monitoring and forecasting can be gradually improved. With a focus on the construction of forest monitoring points， the construction of monitoring and reporting infrastructure should be strengthened. The monitoring and early warning capabilities should be improved utilizing video surveillance and drone equipment coupled with the application of advanced information technology and modern high-tech.
Strengthening epidemic supervision
Forest rangers should well take their monitoring responsibility. The ground grid monitoring based on the monitoring of forest rangers is the main method， supplemented by video monitoring. Multifunctional video monitoring towers are installed at Dabao management and protection station， Changcao management and protection station， and Mazhanggou management and protection station （Table 3） to comprehensively monitor the epidemic situation in the forest area， so as to achieve early detection， reporting， and treatment.
Strengthening prevention and control publicity
By entering villages， distributing leaflets， posting slogans， loudspeakers， WeChat， QQ， Tiktok new media social platform and other forms， we should increase publicity efforts， improve community villagers awareness of the identification， harmfulness， and comprehensive prevention and control technology of pine wood nematode disease， and guide them to actively participate in the prevention and control work and find and report the epidemic in time. In such a way， the efficiency of epidemic prevention and control in the whole society can be improved， and a situation of mass prevention and mass treatment can be formed thereby.
Strengthening joint prevention and control
Implementing epidemic blockade
It is necessary to strengthen quarantine blockage by establishing timber inspection stations at the border of provinces， counties， and farms， as well as traffic safety persuasion stations where "Pine Wood Nematode Disease Quarantine Inspection Station （Card）" signs are hung to fulfill the function of epidemic wood inspection and control， inspect and register incoming and outgoing pine wood and its products one by one， and let relevant persons to fill out the "Station （Card） Quarantine Inspection Registration Form". A reward reporting system and an accountability system should be established and improved to supervise and urge inspectors to fulfill their duties， and promptly report any illegal or irregular behavior to the forest inspection agency of the county and effectively handle it. Inspection stations that are needed to be built and improved are as follows：
One is the interprovincial system， which means to establish pine wood nematode disease inspection checkpoints at the border between Yunyang County and Lichuan City， Enshi Tujia Autonomous Prefecture， Hubei Province. The second is the inter-county system， which means to establish pine wood nematode disease inspection checkpoints at the border of Wanzhou District， Kaizhou District， Fengjie County， and Wuxi County adjacent to Yunyang County. Specifically， pine wood nematode disease inspection checkpoints should be established at following boundaries：
Yongli Village in Bayang Town， Yunyang County and Xiaozhou Town in Wanzhou District， Tongde Village in Pingan Town， Yunyang County and Tiefeng Township in Wanzhou District as well as Zhaojia Town in Kaizhou District， Fengming Town in Yunyang County and Taian Town in Wanzhou District， Shuanghe Community in Shuanglong Town， Yunyang County and Jinfeng Town in Kaizhou District， Jiqing Village in Houye Town， Yunyang County and Zhongbai Village in Kaizhou District， Jindao Village in Longdong Town， Yunyang County and Kangping Village in Fengjie County， Hongchun Village in Guling Town， Yunyang County and Jiagao Town in Fengjie County， Yanping Town in Yunyang County and Yangshi Town in Fengjie County， and Shiliang Community in Shangba Township in Yunyang County and Dabao Village in Wuxi County. The third is the village and town （street， forest farm） system. At the boundaries with Renhe Street， Bayang Town， and Sishibacao Forest Farm， a pine wood nematode disease wood inspection station should be established at the Dabao Management and Protection Station of the Sishibacao Forest Farm.
Strengthening joint efforts with townships to eliminate and treat infected trees
Regarding the border areas between the forest farm and villages and towns as well as flower arrangement areas which are easily neglected and not always all covered during the eradication of diseased trees， various eradication units shall complete the eradication task with quality and quantity assurance， assign dedicated persons to inspect the effectiveness of boundary eradication， and promptly communicate with the other party if there are any doubts about the boundary line to clarify responsibilities. Towns and townships and the forest farm must unify their thinking， actions， strengthen communication， and carry out orderly and effective joint prevention and control to ensure the quality and effectiveness of prevention and control， thereby forming a grid prevention and control system for pine wood nematode disease. The competent department must strengthen supervision over the eradication work in border epidemic areas， and promptly notify both parties to confirm and eliminate diseased trees who are not properly treated. Only in this way can comprehensive eradication be ensured without leaving any blind spots. For the centralized eradication period， it is necessary to unify the eradication measures to ensure efficient eradication.
Strengthening forest management technologies for prevention and control measures
The main tree species in the forest farm are P. massoniana and Cupressus funebris Endl.， with P. massoniana accounting for relatively high proportions of the tree forest area and stock， at 91.33% and 96.26%， respectively， leading to a fast transmission rate and large infection area of pine wood nematode disease， requiring forest stand transformation and adjustment of tree species structure. Resistant tree species should be selected for planting， or resistant tree species can be planted to construct mixed forests， so as to strengthen the resistance of pine forests and appropriately control the outbreak and spread of pine wood nematodes. The transformation of forest structure from single to composite should be promoted， and the ability to resist natural disasters and pests should be enhanced.
Exploring experimental biological control
Every April and May， 8% cypermethrin microcapsule suspension agent can be sprayed in the forest areas of the county using aircrafts. Although this drug does not pollute the environment and does not harm crops， it has an impact on silkworms， bees， fish， and shrimp， and thus cannot be used in surrounding forest areas such as drinking pools and fish ponds， where biological control can be applied in combination.
Applying Beauveria bassiana
B. bassiana is a fungal insecticide that is harmless to humans and livestock and safe to crops， residue free， and pollution-free （toxic to silkworms）. It is an effective biological pesticide for controlling Dendrolimus. In prevention and control practices， releasing the fungus before the larvae overwinter （late November） and after overwintering （February March） is beneficial for the reproduction of B. bassiana due to large rainfall and high forest humidity during this period.
Applying Metarhizium
Metarhizium is usually regarded as a biopesticide， which does not produce the side effects of chemical pesticides， does not pollute and damage the environment， and has a single effect on target pests. It does not kill other natural enemies of pests in nature， and does not make pests resistant to pesticides. In forest areas with a large population and severe diseases of M. alternatus， the use of Metarhizium powder non-woven fabrics for prevention and control during the peak emergence period of M. alternatus can play a role in killing M. alternatus， thereby controlling the large-scale outbreak and spread of pine wood nematodes.
Releasing Scleroderma guani
The eggs of parasitic wasp such as S. guani can be released. The viruses carried by parasitic eggs can kill Dendrolimus on a large scale， and are non-toxic and harmless to humans， livestock， and the environment. At the beginning of the mass spawning period of M. alternatus， sunny and windless days can be chosen to release S. guani in stages in the forest， usually at a density of （0.45-1.6） million individuals per hectare， which could achieve a better control effect.
Releasing Dastarcus helophoroides
D. helophoroides is released at M. alternatuss spawning grooves and the dense distribution sections of sawdust （insect feces）， and the release amount is determined based on the population density of M. alternatus.
Vertical trap trees for prevention and control
Vertical trap trees are suitable for areas where vector insects reproduce one generation per year， and it is strictly prohibited to use them in pine forests on the edge of epidemic sub-compartments， as well as areas that do not have conditions for crushing （chipping） or burning. Before the emergence of local vector insects， it is required to select weakened P. massoniana in the central area of control sub-compartments of pine wood nematode disease as the trap trees. A 10 cm wide girdle is formed by peeling at the chest diameter of each trap tree， and the girdle depth should reach the xylem. One trap tree can be set every 10 mu， and each trap tree can be numbered and located. During the non-emergence period of vector insects in winter and spring each year， the trap trees are cut and crushed （sliced） or burned for eradiation of pests.
Drilling and injection
For the key protected P. massoniana， pesticides such as emamectin benzoate， abamectin， emamectin benzoate microemulsions， abamectin emulsifiable concentrates， and emamectin benzoate-imidacloprid solvable agents should be selected for further prevention of the spread of pine wood nematode disease by drilling and injection. The injection schedule should be arranged during sunny days as much as possible， and the locations of injection holes should be selected while avoiding dead joints， injured parts， and lower branches. After the infusion is completed， the pesticide bottles should be recycled and sealed with a wooden stopper or vaseline. Meanwhile， if it is found that the bark is decaying and the trunk is hollow， the tree holes should be filled in a timely manner and protected with agents. It is also necessary to improve the soil， spray pesticides regularly， and fertilize to promote the rejuvenation of P. massoniana.
Employee performance evaluation mechanism
The prevention and treatment of pine wood nematode disease and its effectiveness should be incorporated into the year-end target performance evaluation， and the performance evaluation should be linked with job evaluation and promotion. Those responsible for conscientiously fulfilling their responsibilities， achieving good prevention and control results， and achieving prevention and control goals are rated as excellent. Units and relevant responsible persons who fail to fulfill their responsibilities seriously， present poor prevention and control effects， and have not achieved the prevention and control goals should be held accountable in accordance with relevant regulations， and should be evaluated as poor in the year-end target performance evaluation of that year.
References
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