CN103477921B - Method for comprehensive control of root knot nematode disease of potted ficus microcarpa - Google Patents

Abstract

The invention provides a method for comprehensive prevention and control of root-knot nematode disease of potted banyan trees, belonging to the field of disease prevention and control of horticultural plants. The present invention aims at the two growth stages of potted banyan tree field cultivation period and greenhouse control period, and integrates and assembles 6 kinds of control measures such as plant quarantine, disease monitoring, horticultural control, physical control, biological control and chemical control, and proposes a method suitable for each growth stage. Phased comprehensive prevention and control measures. The invention can effectively control the occurrence and damage of the root-knot nematode disease of the potted banyan tree, significantly reduce the use frequency and amount of chemical pesticides, and has great significance for improving the ornamental and economic value of the potted banyan tree and protecting the environment.

Description

A kind of comprehensive prevention and control method of potted banyan tree root-knot nematode

technical field

The invention relates to a method for comprehensive prevention and control of root-knot nematode disease of potted banyan trees, belonging to the field of disease prevention and control of horticultural plants.

Background technique

Banyan tree ( Ficus microcarpa ) belongs to the genus Ficus of the family Moraceae. It is often used in the production of bonsai after pruning. Potted banyan trees are the main foreign exchange-earning plant products exported by Fujian Province. They have now gone to the world and are named "China roots". Its species mainly include Ficus microcarpa Linn. f., F. benjamina Linn, F. benjamina cv. Golden Princess, F. microcarpa cv. Golden Leaves, F. elastica cv. The export volume of Deocora Burgundy and F. elastica var. varigate etc. accounted for more than 90% of the international market share.

The planting of potted banyan trees in Fujian has been relatively mature. From the sowing of seeds to the sale of finished products, it needs to go through two growth stages: the field cultivation period and the greenhouse control period. Field cultivation period: from the potted banyan tree seed sowing to the potted banyan tree rooting out of the nursery, this period is mainly to realize the rapid and healthy growth of potted banyan tree seedlings and tubers; shed control period: from the potted banyan tree out of the nursery into the shed room to the potted plant The banyan tree finished products are sold out of the shed. This period is mainly to realize the shape and safe and efficient maintenance of potted banyan trees. In recent years, with the expansion of intensive production scale and the enhancement of root-knot nematode resistance, the two growth stages of potted banyan trees are vulnerable to root-knot nematode damage, and root-knot nematode disease has become one of the most important diseases in the planting process of potted banyan trees. one.

After the root-knot nematode infects the potted banyan tree, it feeds and reproduces on the root, and the lateral roots and vegetative roots are obviously swollen, forming root knots or nodules, with galls, and white pear-shaped females can be seen when the root-knot epidermis is cut; severe infection The surface of the root system is jelly-like, and the root knots are continuous in the shape of beads, or several root knots heal to form root agglomerates, the root system is atrophied and deformed, the lateral roots and root hairs are significantly reduced, and some form clusters or file short roots. The above-ground symptoms are not obvious, like the symptoms of fertilizer or water shortage; severely affected plants are short, weak in growth, yellow in leaves, wrinkled or dry or fall off at the edge of the leaves, and the branches are dry and dead. Once potted banyan trees are infected by root-knot nematodes, not only the growth and quality of the plants will be greatly affected, but also the occurrence of other diseases will be aggravated. At present, there have been some reports on the research on banyan root-knot nematode disease, all of which focus on the identification of pathogenic species and the use of individual control measures. For example, Jiang Dinghuang, Xiao Shun et al. identified the pathogen of root-knot nematode disease of banyan tree as Meloidogyne incognita ; Pan Yonghong et al. reviewed the occurrence regularity and control measures of root-knot nematode on Ficus ginseng, but the operability is not strong; Yang Fan and others determined the control effect of 10% hemiphos GR and 18% abamectin EC on root-knot nematode disease of Ficus ginseng seedlings; et al. Our investigations over the years have found that root-knot nematodes have developed strong drug resistance due to factors such as production management, pesticide types, and application methods, and a single chemical drug cannot completely kill root-knot nematodes; Methyl bromide and other chemical fumigation treatment not only affect the environment and the safety of quarantine personnel, but also affect the ornamental value of potted banyan trees, so the existing fumigants have been gradually banned or restricted. According to the above, there is an urgent need for a set of very effective and operable comprehensive prevention and control measures for root-knot nematode disease in the production of potted banyan trees. The effective integration and assembly of individual measures such as control and chemical control can be effectively applied to the control of root-knot nematodes in the two growth stages of the field cultivation period and the greenhouse control period of potted banyan trees, and at the same time improve the yield and quality of the plants. Based on the analysis of the occurrence and regularity of root-knot nematode damage of potted banyan trees, the present invention effectively summarizes and integrates individual prevention and control measures, and constructs a "healthy seedling + biological control + chemical control" method for the field cultivation period of potted banyan trees. " Based on the prevention and control system, a prevention and control system based on "quarantine + healthy seedlings + bio-control" was established for the control period of the potted banyan tree shed. The occurrence and damage of nematodes can significantly reduce the frequency and amount of chemical pesticides used, protect the natural ecological environment, and enhance the ornamental and economic value of potted banyan trees.

Contents of the invention

The purpose of the present invention is to provide a comprehensive prevention and control method for root-knot nematode disease of potted banyan trees. The method has good production and application effects, can control root-knot nematodes of potted banyan trees within the scope of economic hazard threshold indicators, and can improve the viewing and viewing of potted banyan trees. Economic value and environmental protection are of great significance.

The technical scheme that the present invention takes is as follows:

The present invention aims at the two growth stages of the potted banyan tree field cultivation period and the greenhouse regulation period, and constructs a comprehensive prevention and control method suitable for each growth stage. The specific prevention and control methods include:

(1) Field cultivation period

Combining horticultural control, biological control and chemical control, build a prevention and control system based on "healthy seedlings + biological control + chemical control";

Among them, horticultural control:

①Cultivation of healthy seedlings: Use quarantined and sterilized cultivation media for seedling cultivation, or purchase tissue culture seedlings produced by regular seedling companies, and at the same time, when transplanting seedlings, add raw tea with a weight ratio of about 10% to the cultivation medium Bran powder to prevent the growth of root-knot nematodes and achieve the effect of promoting root and seedling growth;

② Reasonable crop rotation: After 2 to 3 years of planting potted banyan trees in the nursery, 2 to 3 crops of vegetables, which are weak host plants for root-knot nematodes, should be rotated;

Biological control: When finishing the nursery, spread about 50 kg of raw tea bran powder and an appropriate amount of decomposed organic fertilizer per mu; for seedlings with 5 to 6 true leaves after sowing, use 20.0 to 100.0 mg/kg of Avi Irrigate the roots with the original slurries of abamectins to prevent and control the occurrence of root-knot nematodes; for bagged seedlings, when the number of root-knot nematodes in the banyan tree reaches 1-2 head/plant, use 20.0-100.0 mg/kg abamectin original slurries Irrigate the roots once every 5 to 7 days to kill and control the occurrence of root-knot nematodes. At the same time, use 10 billion/gram of live spore Paecilomyces lilacinus in rotation, and apply them in holes near the roots of seedlings. The dosage per mu is 1-2 kg;

Chemical control: When the number of root-knot nematodes in the banyan tree reaches 3-5 heads/plant, spray with 33.0-100.0 mg/kg chlorpyrifos EC to control the reproduction of root-knot nematodes, spray once every 7 days; /kg Abamectin protoplasm is applied in rotation;

(2) Greenhouse control period

Combining plant quarantine, horticultural control and biological control, build a prevention and control system based on "quarantine + healthy seedlings + biological control";

Among them, plant quarantine: cut off all the fibrous roots of potted banyan plants transported into the shed, and then soak them in 20.0-100.0 mg/kg abamectin stock solution for 1-2 minutes to kill and control the occurrence of root-knot nematodes. The roots are dried and burned in the sun; when the semi-finished products are planted on the plate, the cultivation medium that has been quarantined and disinfected should be selected, and raw tea bran powder accounting for about 10% by weight should be added to the cultivation medium to prevent root-knot nematodes In the process of planting and before the finished product leaves the shed, the inspection and quarantine of potted banyan trees shall be strictly implemented; at the same time, during the two peak periods of root-knot nematode disease in potted banyan trees, disease monitoring shall be strengthened as appropriate, so as to provide comprehensive prevention and control measures. use the data provided for decision-making;

Horticultural control: pay attention to the cultivation of resistant seedlings. When modeling potted banyan trees, the disease resistance and susceptibility of the species should be fully considered, and modeling grafting should be carried out on the rhizomes of high-resistant varieties to improve plant disease resistance and reduce damage caused by root-knot nematodes of potted banyan trees. ; During the cultivation of potted banyan trees, off-the-ground cultivation measures should be taken, and deep well water or tap water should be used for irrigation, and the number of root-knot nematodes should be monitored selectively. For countries with strict quarantine requirements such as the United States and Canada, the cultivation medium that has been quarantined and disinfected should be replaced again before export to ensure that it does not carry any harmful organisms including root-knot nematodes;

Biological control: Irrigate the roots with 20.0-100.0 mg/kg abamectin stock solution to prevent the occurrence of root-knot nematodes, and irrigate once every 15 days; When root-knot nematodes are planted, the frequency of root irrigation with abamectin original slurry should be increased, once every 5 to 7 days to kill and control the spread of root-knot nematodes; at the same time, it should be applied in rotation with 10 billion/gram of live spore Paecilomyces lilacinus .

Comprehensive prevention and control method of the present invention is based on as follows:

1. Mastered the pathogenic species of potted banyan tree root-knot nematode

The root-knot nematodes that cause damage to potted banyan trees mainly include M. incognita and M. arenaria . In the production base of potted banyan trees in Zhangzhou, Fujian Province, we collected samples of potted banyan tree roots and cultivation substrates for isolation. By observing the overall morphological characteristics of the isolated adults and 2nd instar larvae, we identified the dominant species of potted banyan tree root-knot nematode as southern root-knot nematode. nematodes. The female adults of this nematode live in the root knots of potted banyan trees. The body becomes spherical or pear-shaped after swelling. In front of the middle esophageal bulb, usually near the base of the stylet; the perineal pattern is nearly square, with a high dorsal arch, and the cuticle pattern is smooth to wavy, with fractured and forked patterns. The male adult of this nematode is free in the medium or attached to the oocyst, worm-shaped, colorless and transparent, with a body length of 1.00-2.00 mm and a body width of 0.03-0.04 mm; obvious body ring, well-developed skull skeleton and stylet; well-developed spicules , leading crescent-shaped, no mating umbrella. The eggs of this nematode are laid in the colloidal oocyst secreted by the tail, oval or nearly kidney-shaped; the 2nd instar larvae are slender, worm-shaped, colorless and transparent, the stylet is slender, the middle esophageal bulb is developed, and the tail is cone-shaped Shaped, often constricted near the caudal end, with a clear hyaline zone at the end.

2. Mastered the occurrence law of potted banyan tree root-knot nematode

In the potted banyan production base in Zhangzhou, Fujian, the dominant species of root-knot nematode is root-knot nematode incognita. Its distribution in the potted banyan planting area is very uneven, and nematode diseases also occur to varying degrees due to their uneven distribution. The survey found that the insect survived the winter in the cultivation medium as eggs or 2nd instar larvae. When the environmental conditions were suitable in the next year, the hatched larvae and overwintered larvae took the opportunity to invade the young roots of banyan trees, moved between root cells without any differentiation, and finally endoparasited in the root Growth and development in the stele and cortex. The insect only needs 20-25 days to complete a life cycle, and can complete 5-10 generations every year, with serious generation overlap.

Environmental temperature, humidity and cultivation medium are the main factors affecting the occurrence of root-knot nematode in potted banyan tree. Throughout the year, as the temperature rises in spring, the root system grows actively, nematodes multiply rapidly, and the population number shows an increasing trend, reaching the highest peak in autumn; after that, affected by adverse environmental conditions such as low temperature in winter, the root system growth slows down, and the population number rapidly diminished. When the temperature of the cultivation medium is 25-30°C, the growth of root-knot nematode is optimal and the damage is the greatest; when the temperature is higher than 40°C or lower than 5°C, the hatching of root-knot nematode eggs is inhibited and the activity of larvae is significantly weakened, and the damage is reduced.

3. Master the transmission mode of potted banyan tree root-knot nematode

The mobility of root-knot nematode larvae is weak, and their own moving distance is only 20-30 cm, and they mainly rely on diseased plants, cultivation media and irrigation water for transmission. The survey found that production enterprises and farmers basically did not consider comprehensive control measures from the perspective of cutting off the transmission route, but used a large amount of nematocide chemicals to prevent and control root-knot nematode damage when the disease intensified. Therefore, "3R "And phytotoxicity and other serious problems have greatly affected the ornamental and economic value of potted banyan trees, and also destroyed the ecological and natural environment for planting.

4. Comprehensive prevention and control methods

The comprehensive prevention and control method of potted banyan tree root-knot nematode disease should follow the plant protection policy of "prevention first, comprehensive prevention and control". In the two growth stages of field cultivation and greenhouse regulation of potted banyan trees, integrated assembly and application of plant quarantine, disease monitoring, Horticultural control, physical control, biological control and chemical control and other prevention and control technical measures, to build a corresponding prevention and control system based on "healthy seedlings + biological control + chemical control" and "quarantine + healthy seedlings + biological control".

Main prevention and control measures:

(1) Plant quarantine

Root-knot nematodes generally survive in the soil of 5-30 cm, with the largest number at the depth of 10-20 cm. Root-knot nematode survives the winter as eggs or larvae left in the soil or cultivation medium along with the diseased residue, and the survival period is usually 1 to 3 years. Root-knot nematode is mainly transmitted by cultivation medium, diseased seedlings and irrigation water, and the mutual use of seedlings among farmers and the cross-use of farm tools provide a way for the spread of root-knot nematode disease. Therefore, comprehensive control measures should be considered from the perspective of cutting off the transmission route. Do not blindly use a large amount of line-killing chemical agents. Try not to straddle sheds during farming operations and when farmers use seedlings with each other, they should be cleaned, cut off fibrous roots, soaked in chemicals, etc. Measures, and then planted to reduce artificial expansion of distribution. At the same time, root-knot nematodes are easy to spread long-distance with seedlings and soil, so the fibrous roots of potted banyan plants that are transported into the shed should be cut off, and then soaked in 20.0-100.0 mg/kg abamectin stock solution for 1-2 minutes , to kill and control the occurrence of root-knot nematodes, and at the same time, dry and burn the cut-off roots; when planting semi-finished products, the cultivation medium that has been quarantined and disinfected should be selected, and the weight ratio of about 10% raw tea bran powder to prevent the occurrence of root-knot nematodes; during the planting process and before the finished product leaves the shed, strict inspection and quarantine of potted banyan trees; at the same time, during the two peak periods of root-knot nematodes in potted banyan trees , Strengthen disease monitoring as appropriate, and provide decision-making data for the selection and use of comprehensive prevention and control measures.

(2) Disease monitoring

Throughout the year, as the temperature rises in spring, the root system of potted banyan trees grows actively, root-knot nematodes multiply rapidly, and the population number shows an increasing trend, reaching the highest peak in autumn. Slowly, the number of populations decreased rapidly. When the temperature of the cultivation medium is 25-30 ℃, the growth of root-knot nematode is optimal and the damage is the greatest; when the temperature is higher than 40 ℃ or lower than 5 ℃, the hatching of root-knot nematode eggs is inhibited and the activity of larvae is significantly weakened, and the damage is reduced. Therefore, in spring and autumn, root-knot nematode disease monitoring should be carried out in combination with local climate conditions and the growth and development of potted banyan trees.

(3) Horticultural control

① Pay attention to seedling cultivation

Cultivation of healthy seedlings: use quarantined and sterilized cultivation media for seedling cultivation, or purchase tissue culture seedlings produced by regular seedling companies, and add about 10% raw tea bran to the cultivation medium when transplanting seedlings powder to prevent the growth of root-knot nematodes and achieve the effect of promoting strong roots and seedlings;

Cultivation of resistant seedlings: When modeling potted banyan trees, the disease resistance and susceptibility of the species should be fully considered, and modeling grafting should be carried out on the rhizomes of high-resistant varieties as much as possible to improve the disease resistance of the plants and reduce the damage caused by root-knot nematodes of potted banyan trees; During the planting period of potted banyan trees, off-the-ground cultivation measures should be taken, deep well water or tap water should be used for irrigation, and the number of root-knot nematodes should be monitored selectively. Once root-knot nematodes are found, nematode treatment should be carried out to avoid re-infection of root-knot nematodes; In countries with strict quarantine requirements such as Canada and Canada, the cultivation medium that has been quarantined and disinfected should be replaced again before export to ensure that it does not carry any harmful organisms including root-knot nematodes.

② Reasonable crop rotation

After 2 to 3 years of planting potted banyan trees in the nursery, 2 to 3 stubbles of vegetables, which are weak host plants for root-knot nematodes, should be rotated, such as rape, pepper, onion, garlic, etc., to increase the diversity of soil organisms and reduce the damage caused by root-knot nematodes. the

(4) Physical control

① Strengthen field and shed management

Do a good job in the cleanliness, weed control and nematode killing of seedling sheds, nurseries and sheds, timely cleaning of dead branches, fallen leaves and weeds, combined with pruning, and timely cutting off dense branches, dead branches and diseased branches to improve ventilation Light conditions, reduce the source of disease.

② Soil and matrix disinfection

When the temperature is high in summer, after cleaning the nursery, dig the nursery soil or cultivation substrate to a depth of about 30 cm, and then evenly spread about 50 kg of raw tea bran powder and an appropriate amount of decomposed organic fertilizer per acre, and then irrigate an appropriate amount of Biocide—abamectin original slurry, etc., and finally plow the soil or cultivation substrate to make it fully mixed with tea bran powder, organic fertilizer and avermectin original slurry; The width depends on the size of potted banyan seedlings; then cover the soil or cultivation substrate with plastic film to make it completely closed; then pour deep well water or tap water from under the plastic film to the border until the border surface is moist and the soil or substrate moisture content reaches 70% or so; after 20 days of sealing, remove the plastic film to dry, ventilate or dry for 2 days, and after disinfection is completed, you can sow or transplant seedlings.

(5) Biological control

Root-knot nematodes are mainly controlled by biological control nematicides, such as abamectin, Paecilomyces lilacinus, tea bran cake and other nematicide biological control agents. When finishing the nursery, spread about 50 kg of raw tea bran powder and an appropriate amount of decomposed organic fertilizer per mu; for seedlings that grow 5 to 6 true leaves after sowing, use 20.0 to 100.0 mg/kg of pro-abamectin Irrigate the roots with slurry to prevent and control the occurrence of root-knot nematodes; for bagged seedlings in the nursery, when the number of root-knot nematodes in the banyan tree reaches 1-2 heads/plant, use 20.0-100.0 mg/kg avermectin original slurry to irrigate Roots are irrigated once every 5 to 7 days to kill and control the occurrence of root-knot nematodes. At the same time, they are applied alternately with 10 billion/gram of live spore Paecilomyces lilacinus fungi, and applied in holes near the roots of seedlings, per mu The dosage is 1-2 kg; for potted banyan trees in the greenhouse, use 20.0-100.0 mg/kg abamectin stock solution to irrigate the roots to prevent the occurrence of root-knot nematodes, and irrigate once every 15 days; if potted banyan trees are found When the population of root-knot nematodes reaches 1-2 heads/plant, the frequency of root irrigation with abamectin stock solution should be increased, once every 5-7 days, to kill and control the spread of root-knot nematodes; Live spores of Paecilomyces lilacinus were applied in rotation.

(6) Chemical control

Root-knot nematode disease is the main aspect that restricts the export of potted banyan trees. Almost all countries list it as an object that needs to be quarantined. Once live nematodes are detected, all light nematodes should be fumigated, and heavy ones should be destroyed immediately. Export enterprises and flower farmers have caused serious losses. However, chemical control should be used in the field as much as possible. In the field, when the population of root-knot nematodes of banyan trees reaches 3-5 heads/plant, spray with 33.0-100.0 mg/kg chlorpyrifos EC to control the reproduction of root-knot nematodes, and every 7 days Spray once a day, and try to use less or no granules such as Yishubao and carbofuran; since the frequency of chlorpyrifos-resistant individuals is still high, continuous application should be avoided, and as much as possible with 20.0-100.0 mg/kg Avermectin Alternative use of abamectin and abamectin in order to delay the emergence of highly resistant individuals.

The remarkable advantage of the present invention is that: the present invention can effectively control the root-knot nematode damage of the potted banyan tree, significantly reduce the use frequency and amount of pesticides, and has great significance for improving the ornamental and economic value of the potted banyan tree and protecting the environment.

Description of drawings

Figure 1 is a map of the damage caused by root-knot nematodes of banyan trees.

Figure 2 shows the control effects of different nematicide chemicals on root-knot nematodes.

Figure 3 shows the control effects of different nematode-killing chemicals on root-knot nematodes.

Detailed ways

The present invention will be further described by examples below, and these descriptions are not intended to further limit the content of the present invention. Those skilled in the art should understand that equivalent replacements or corresponding improvements made to the contents of the present invention still fall within the protection scope of the present invention.

1. Solve the problem of selection of some prevention and control measures

(1) Monitoring of root-knot nematode occurrence

The production process of potted banyan trees is susceptible to damage by Meloidogyne incognita and peanut root-knot nematodes ( M. arenaria ), which seriously affects the growth cycle and appearance quality of potted banyan trees, which in turn affects the export of potted banyan trees. For this reason, we took the Zhangzhou export potted banyan tree planting demonstration base as the observation point to study or monitor the occurrence and regularity of root-knot nematode disease in potted banyan trees. The summary of the experiments is as follows:

Experimental material: the test plant is about 250 g export potted banyan tree (Zhangzhou, Fujian).

experimental method:

Occurrence investigation: In Zhangzhou, Fujian Province, the main place of origin of potted banyan trees, root-knot nematode disease investigations were selected in concentrated planting areas, and the symptoms, incidence patterns, and transmission control were recorded and analyzed.

Pathogen isolation and identification: collect the root system of the infected banyan tree, cut the root system into 0.5 cm long pieces, wrap it in double gauze and separate it with the improved Bellman funnel method, separate the female worms in the root tissue by dissecting them, and collect the separated nematodes In small test tubes filled with a small amount of water, divide into 2 groups and store in a refrigerator at 4°C for use. One group was used to prepare insect source soil, inoculated with 6 root-knot nematodes per gram of insect source soil, and inoculated back for the nematode control effect test; the other group was heated in a constant temperature water bath at 65 ℃ for 2-3 minutes, and the Add the same amount of TAF or FAG fixative solution equal to the nematode suspension in the test tube to fix and store, observe the morphological characteristics of root-knot nematode adults and 2nd instar larvae through the B203LEDTR biological microscope of Chongqing Auto Optical Instrument Co., Ltd., and identify the pathogenic species .

Experimental results

The occurrence of root-knot nematode

Symptoms of damage: Root-knot nematodes of potted banyan trees feed and multiply on the roots. After the roots are damaged, the lateral roots and vegetative roots are obviously swollen, forming root knots with galls, and white pear-shaped females can be seen when the root-knot epidermis is cut; severe infection The surface of the root system is jelly-like, and the root knots are continuous in the shape of beads, or several root knots heal to form root agglomerates, the root system is atrophied and deformed, the lateral roots and root hairs are significantly reduced, and some form clusters or file short roots. The above-ground symptoms are not obvious, like the symptoms of fertilizer or water shortage; severely affected plants are short, weak in growth, yellow in leaves, wrinkled or dry or fall off at the edge of the leaves, and the branches are dry and dead.

Incidence law: The distribution of root-knot nematodes in potted banyan tree planting areas is very uneven, and nematode diseases also occur with this uneven distribution. The survey found that the insect survives the winter in the cultivation medium as eggs or 2nd instar larvae. When the environmental conditions are suitable in the following year, the hatched larvae and overwintered larvae take the opportunity to invade the young roots of banyan trees, move among the root cells without any differentiation, and finally settle in the roots. Growth and development in the inner column and cortex. Root-knot nematodes only need 20-25 days to complete a life cycle, and can complete 5-10 generations per year, with serious generation overlap.

Environmental temperature, humidity and cultivation medium are the main factors affecting the occurrence of root-knot nematode in potted banyan tree. Throughout the year, as the temperature rises in spring, the root system grows actively, nematodes multiply rapidly, and the population number shows an increasing trend, reaching the highest peak in autumn; after that, affected by adverse environmental conditions such as low temperature in winter, the root system growth slows down, and the population number rapidly diminished. When the temperature of the cultivation medium is 25-30 ℃, the growth of root-knot nematode is optimal and the damage is the greatest; when the temperature is higher than 40 ℃ or lower than 5 ℃, the hatching of root-knot nematode eggs is inhibited and the activity of larvae is significantly weakened, and the damage is reduced.

Transmission control: The survey found that the second instar larvae of root-knot nematodes have weak mobility, and their own moving distance is only 20-30 cm. Root-knot nematode disease in potted banyan trees mainly depends on diseased plants, cultivation media and irrigation water for transmission; production enterprises and planters Farmers basically do not consider comprehensive control measures from the perspective of cutting off the transmission route. They only use a large number of nematodes to prevent and control root-knot nematode damage when the disease intensifies. The "3R" and phytotoxicity problems are serious and have affected Exported potted banyan trees.

Isolation and identification of pathogenic nematodes

Observing the overall morphological characteristics of isolated adults and 2nd instar larvae, the dominant species of root-knot nematode of potted banyan trees in Zhangzhou, Fujian Province is root-knot nematode. The female adult lives in the root knot, the worm body expands into a spherical or pear shape, the body wall is soft, milky white, the body length is 0.44-1.59 mm, and the width is 0.26-0.81 mm; the neck is obvious, and the excretory hole is located in front of the middle esophageal bulb, usually in the Near the base of the stylet; the pattern of the perineum is nearly square, the dorsal arch is higher, the cuticle pattern is smooth to wavy, and there are fracture lines and fork lines. Male adults free in the medium or attached to oocysts, worm-shaped, colorless and transparent, body length 1.00-2.00 mm, width 0.03-0.04 mm; body ring obvious, skull skeleton and stylet well developed; copulation spines well developed, leading belt new Moon-shaped, no mating umbrella. Eggs are laid in colloidal oocysts secreted at the tail end, oval or nearly kidney-shaped, 0.07-0.13 mm long, 0.03-0.05 mm wide, and there are 100-300 eggs in one oocyst. The 2nd instar larvae are slender, worm-shaped, colorless and transparent, the stylet is long and thin, the middle esophageal bulb is developed, the tail is conical, and the tail is often constricted; there is a clear transparent area at the end; the tail of the 3rd to 4th instar larvae It is enlarged and cystic, with caudal pincers, and parasitizes in the root knot.

summary

The dominant species of root-knot nematode in potted banyan tree is mainly root-knot nematode incognita. The distribution of the insect in the planting area is very uneven. It overwinters in the cultivation medium with eggs or 2nd instar larvae, feeds and reproduces on the roots, and can complete 5 to 10 generations each year. The overlap is serious, which can directly affect the growth and development of plants. It can aggravate the occurrence of other diseases such as Fusarium wilt, which is basically consistent with domestic reports.

The root-knot nematode disease of potted banyan tree mainly depends on diseased plants, cultivation media and irrigation water for transmission. Comprehensive control measures should be considered from the perspective of cutting off the transmission route, and blindly using a large number of nematodes must not be used. Suggestion: Cut off all the fibrous roots of potted banyan plants transported into the shed, and then soak them in 20.0-100.0 mg/kg avermectin puree for 1-2 minutes to prevent and control the occurrence and spread of root-knot nematodes. The roots of the potted banyan trees should be dried and burned in the sun; when the semi-finished products are planted on the plate, the cultivation medium that has undergone quarantine and disinfection treatment should be used to effectively reduce the population of root-knot nematodes in the potted banyan tree during the planting process. During the recovery period of potted banyan trees, off-the-ground cultivation measures should be taken, deep well water or tap water should be used for irrigation, and the number of root nematodes should be monitored at their own choice. When a threshold value is reached, nematode treatment should be carried out to avoid re-infection of root-knot nematodes as much as possible. . For countries with strict quarantine requirements such as the European Union, the United States, and Canada, the quarantine system is strictly implemented before export, and the sterilized cultivation medium is replaced again to ensure that no harmful organisms are carried.

(2) Screening of biological control agents and chemical control agents

Due to the large-scale development and continuous planting of greenhouses and greenhouses, the incidence of root-knot nematodes has shown an increasing trend year by year in recent years. It has become the most common and most harmful and difficult disease that affects the safety of potted banyan products. At the same time, the occurrence of nematodes It has also aggravated the harm of soil-borne diseases such as fusarium wilt, verticillium wilt, and blight. Although chemical nematicides have good control effects, they have problems such as high cost, potential pollution, short-lasting effect, and drug resistance. Pesticide technology has been applied in agricultural production and achieved certain results. The effects of bio-nematicides and chemical nematicides on root-knot nematode control are evaluated, in order to provide an ideal choice of pesticides for the control of root-knot nematode in production.

Test materials: the test agents include avermectins puree (Avermectins, product of Anuoxin Co., Ltd.), 40% chlorpyrifos emulsifiable concentrate (Chlorpyrifos, product of Jiangsu Baoling Chemical Co., Ltd.), 10% Yishubao granule ( Mocap, product of Bayer, Germany), 5% carbofuran granule (Carbofuran, product of Hunan Haili Chemical Co., Ltd.). The test plant was about 250 g potted banyan tree (Zhangzhou, Fujian).

experiment method:

matrix kill test

Potted banyan trees with uniform cultivation conditions and growth trends were selected, and 6 groups of treatments were set up according to Table 1, of which 4 groups were treated with different chemicals, and 2 groups were blank controls without adding chemicals; each group treated 9 pots of banyan trees, repeated 3 times. Before spraying, select a group of blank controls to measure the population of root-knot nematodes in the cultivation substrate. Afterwards, the watering test with different pesticides was carried out, the watering amount was 150 mL/pot, and the pesticide was applied twice continuously with an interval of 3 days; the other group of blank control group was watered with the same amount of water. Put it on the cement board after watering, and detect the root-knot nematode population of each potted banyan tree cultivation substrate 15 days later. Root-knot nematodes were separated by the improved Bellman funnel method. After separation, the population of root-knot nematodes was observed with the SZ-760 stereo microscope of Chongqing Auto Optical Instrument Co., Ltd., and the control effect was statistically analyzed with DPS 6.55 statistical software to evaluate the sensitivity.

Nematode control effect test

Potted banyan trees with no root-knot nematode and uniform growth trend were selected, and the roots were washed and replanted in plastic pots with a diameter of 15 cm. 250 g of insect source soil was mixed with the soil for each pot, and placed on cement boards for cultivation after colonization. Select diseased potted plants, set up different drug concentration treatments and blank controls according to Table 2, and treat 3 pots of banyan trees for each treatment, and repeat 3 times. After that, the watering test of different pesticides was carried out, the watering amount was 150 mL/pot, and the pesticide was applied twice continuously with an interval of 3 days; routine management after the medicine was carried out, and the disease index was investigated after 45 days, and the control effect was statistically analyzed with DPS 6.55 statistical software to evaluate the sensitivity sex. The disease classification criteria are as follows: Grade 1 no nodules; Grade 2 with 1 to 2 nodules; Grade 3 with 3 to 30 nodules; Grade 4 with 31 to 100 nodules; Grade 5 with more than 100 nodules. .

Test results: ① Control effects of different nematicide chemicals on root-knot nematodes. The results of the matrix killing test are shown in Figure 2. It can be seen that the control effect of avermectin puree on potted banyan root-knot nematode is the best, and the control effects of the three treatment concentrations are all above 90.0%, and there is no significant difference; followed by chlorpyrifos EC, three treatments The prevention and control effects of the concentrations reached more than 80.0%, and there was no significant difference; the prevention and control effects of 20.0 mg/kg avermectin puree reached 90.4%, while the prevention and control effects of 20.0 mg/kg chlorpyrifos EC were only 82.0%, to achieve the same prevention and control effect, the use concentration must reach 100.0 mg/kg or more. The control effect of Yishubao granules is not good, and the control effect of 4.0g/pot is only 56.5%. The control effect of carbofuran granule was the worst, and the control effect of 4.0 g/pot was only 20.7%. The sensitivity evaluation showed (Table 1) that root-knot nematodes were sensitive to abamectin puree and chlorpyrifos EC, and the LD ₅₀ were 0.2154 mg/kg and 0.2155 mg/kg, respectively, with no significant difference; the LD ₅₀ of carbofuran was 21.6729 g/pot, 6.08 times that of Yishubao.

② Control effects of different nematicide chemicals on root-knot nematodes. The results of the nematode control effect test are shown in Figure 3. It can be seen that the control effect of abamectin puree and chlorpyrifos EC on root knot nematodes of potted banyan trees is relatively ideal, and the control effect of 100.0 mg/kg abamectin puree reaches 95.7%, which is significantly better than the other five treatment; the control effects of 33.3 mg/kg and 20.0 mg/kg abamectin puree and 100 mg/kg and 33.3 mg/kg chlorpyrifos EC were above 73.8%, and there was no extremely significant difference between the treatments, but extremely significant Better than 20.0 mg/kg chlorpyrifos EC. Yishubao Granules and Carbofuran Granules are not very effective in controlling root-knot nematodes of potted banyan trees, and the control effect of the two agents at 4.0 g/pot is comparable to that of 20.0 mg/kg chlorpyrifos EC. Between 60.1% and 66.2%, there was no extremely significant difference; the control effect of the two agents increased with the increase of the dose, but there was no extremely significant difference in the control effect between the same doses. None of the four pesticides had adverse effects on the export potted banyan trees, and the plants grew normally. The sensitivity evaluation showed (Table ₁ ) that the LD ₅₀ of root-knot nematodes to abamectin puree was 8.6480 mg/kg, which was 3.10 times that of chlorpyrifos; 1.35 times of treasure. Analyzing the slope b value of the virulence regression equation, chlorpyrifos is the smallest, and the frequency of resistant individuals is high. Continuous application should be avoided, and it should be used alternately with avermectin as much as possible to delay the emergence of highly resistant individuals.

Table 1 Sensitivity of root-knot nematodes to different nematicidal chemicals

Note: Multiple comparison results in the same column, the same letter means no significant difference, different letters mean significant difference, uppercase letters mean extremely significant difference (P=0.01), lowercase letters mean significant difference (P=0.05), the same below.

Conclusions: ① Abamectin puree and chlorpyrifos EC have ideal control effects on export potted banyan substrate and root knot nematodes without phytotoxicity, which are significantly better than the two granules Yishubao and Carbofuran. The substrate and root root-knot nematodes were sensitive to abamectin puree and chlorpyrifos EC, with LD50 of 0.2154 mg/kg, 0.2155 mg/kg and 8.6480 mg/kg, 2.7927 mg/kg, respectively. To prevent and control the occurrence of root-knot nematode disease in potted banyan trees for export, it is recommended to use 20.0-100.0 mg/kg abamectin puree or 33.0-100.0 mg/kg chlorpyrifos EC, and use granules such as Yishubao and carbofuran as little as possible; Due to the high occurrence frequency of chlorpyrifos-resistant individuals, continuous application should be avoided, and it should be used alternately with abamectin as much as possible to delay the emergence of highly resistant individuals. ② The use of line-killing chemical agents is still the most effective means to control root-knot nematodes, but the increase in dosage and frequency of use, and the aggravation of "3R" and phytotoxicity problems will definitely reduce the use of chemical pesticides. Therefore, we should strengthen the selection of resistant potted banyan species, strengthen the research and development of fungal and bacterial biological anti-nematode preparations, strengthen the research and development of those plant-derived compounds with high activity and easy degradation, and effectively use genetic engineering and molecular biotechnology for nematode control.

2. Application of prevention and control measures at each stage

(1) Field cultivation period

① Before sowing, weed control, nursery cleaning, soil soaking, digging, disinfection and whole border; at the same time, sprinkle tea bran powder and decomposed organic fertilizer;

②Strictly implement the plant quarantine system, avoid cross-infection, and deal with diseased seedlings in a timely manner;

③When the seedlings grow to 5-6 leaves, apply bacterial fertilizer once a week, mainly water and fertilizer, and use 20.0-100.0 mg/kg abamectin stock solution to irrigate the roots;

④ Carry out condition monitoring;

⑤ For bagged seedlings, when the root-knot nematode population of banyan tree is found to be 1-2 heads/plant, use 20.0-100.0 mg/kg abamectin stock solution to irrigate the roots once every 5-7 days; When the population of banyan root-knot nematodes reaches 3-5 heads/plant, spray with 33.0-100.0 mg/kg chlorpyrifos EC, spray once every 7 days; at the same time, use 20.0-100.0 mg/kg abamectin in rotation. the

Through the above comprehensive prevention and control methods, the diseased plant rate of potted banyan trees can be controlled within 5%, which greatly reduces the source of primary infection.

(2) Greenhouse control period

① Clean the shed and prevent weeds;

② All the fibrous roots of the potted banyan plants transported into the shed were cut off, and then soaked in 20.0-100.0 mg/kg abamectin stock solution for 1-2 minutes, and the cut-off roots were dried and burned in the sun; during planting and out of the shed Strictly implement the inspection and quarantine system, and strengthen disease monitoring as appropriate;

③ When modeling potted banyan trees, graft them on the rhizomes of high-resistant varieties to improve the plant's disease resistance; water deep well water or tap water and fertilize timely, and at the same time sprinkle raw tea bran powder and decomposed organic fertilizer, and pruning in time ;

④ Carry out condition monitoring;

⑤ Irrigate the roots with 20.0-100.0 mg/kg abamectin stock solution, and irrigate once every 15 days; The root irrigation frequency of the original slurry is once every 5 to 7 days; at the same time, it is applied alternately with the 10 billion/g live spore Paecilomyces lilacinus fungus.

Through the above comprehensive prevention and control methods, the use of pesticides can be reduced by 1 or 2 times, and the potted banyan trees for sale are basically free of root-knot nematodes.

3. Comprehensive application

From 2011 to the present, the potted banyan tree planting base in Zhangzhou, Fujian Province has used the comprehensive prevention and treatment method for root-knot nematode disease of potted banyan trees according to the present invention to comprehensively prevent and control the root-knot nematode disease of potted banyan trees in two growth stages, which has significantly improved potted banyan trees. The ecological environment of the planting base reduces pesticide damage and pesticide residues, forming a virtuous cycle of root-knot nematode ecological regulation, which has good ecological benefits; the diseased plant rate of root-knot nematode disease in potted banyan trees in the field can be controlled within 5% , and the potted banyan trees sold basically have no root-knot nematode, which saves labor and time, and the added profit per mu is more than 2,000 yuan, which has good economic benefits; The awareness and level of prevention and control can make potted banyan trees meet the quarantine requirements to a greater extent, improve product quality and export volume, and further promote the healthy and sustainable development of the industry, which has good social benefits.

Claims (1)

1. a Synthetical prevention method for potted plant banyan root knot nematode disease, is characterized in that: for potted plant banyan land for growing field crops nurturing period and canopy room regulation and control phase 2 vegetative stages, build the Synthetical prevention method being applicable to each vegetative stage; Concrete preventing control method comprises:

(1) the land for growing field crops nurturing period

In conjunction with gardening control, biological control and chemical control, building " strong seedling+biological and ecological methods to prevent plant disease, pests, and erosion+chemoprevention " is main prevention and control system;

Wherein gardening control:

1. strong seedling is cultivated: select the cultivation medium nursery through quarantining, disinfecting, or buy the plantlet in vitro of regular nursery company production, simultaneously when transplanting seedling, in cultivation matrix, adding the raw tea bran powder of weight accounting 10%, growing and reaching the effect in short root strong sprout to prevent root-knot nematode;

2. efficent rotation: ground, garden planting pot banyan, after 2 ~ 3 years, answers the weak host plant-vegetables of crop rotation root-knot nematode 2 ~ 3 batches;

Biological control: when arranging ground, garden, every mu is spread fertilizer over the fields raw tea bran powder 50 kg and appropriate decomposed manure; To after planting to the seedling growing 5 ~ 6 true leaves, with 20.0 ~ 100.0 mg/kg Avermectin magma liquid irrigating roots, the generation of prevention and corntrol root-knot nematode; Seedling is planted to bag, when finding that banyan root-knot nematode insect population reaches 1 ~ 2 head/plant, with 20.0 ~ 100.0 mg/kg Avermectin magma liquid irrigating roots, root is filled with 1 time every 5 ~ 7 days, to kill and to control the generation of root-knot nematode, use with a 10000000000/gram spore Paecilomyces lilacinus microbial inoculum alive rotation, spread manuer in holes near seedling root system, every mu of consumption is 1 ~ 2 kg simultaneously;

Chemical control: when finding that banyan root-knot nematode insect amount reaches 3 ~ 5 heads/plant, with 33.0 ~ 100.0 mg/kg chlorpyrifos ec sprayings, controls root-knot nematode breeding, every spray in 7 days 1 time; Use with 20.0 ~ 100.0 mg/kg Avermectin magma rotations simultaneously;

(2) the canopy room regulation and control phase

In conjunction with plant quarantine, gardening control and biological control, building " quarantine+strong seedling+biological and ecological methods to prevent plant disease, pests, and erosion " is main prevention and control system;

Wherein plant quarantine: exchange the potted plant banyan plant transported into canopy room and all wipe out fibrous root, 1 ~ 2 min is soaked afterwards with 20.0 ~ 100.0 mg/kg Avermectin virgin pulp liquids, kill and control the generation of root-knot nematode, the root wiped out is carried out drying burning process simultaneously; On semi-finished product during dish plantation, the cultivation medium through quarantining, disinfecting should be selected, in cultivation medium, add the raw tea bran powder of weight accounting 10%, to prevent the generation of root-knot nematode; In breeding process and before finished product goes out canopy, to the inspection and quarantine of potted plant banyan strict implement; Meanwhile, in pathogenetic 2 peak periods of potted plant banyan root-knot nematode, take the circumstances into consideration to strengthen state of illness monitoring work, for the choice for use of comprehensive measures for the prevention and control provides decision data;

Gardening is prevented and treated: focus on resistance seedling and cultivate, during potted plant study of plastic in Chinese banyan, should take into full account the resistant, susceptible of kind, the rhizome of high resistance kind carries out moulding grafting, improve plant disease resistance, reduce causing harm of potted plant banyan root-knot nematode; During potted plant banyan breeding, liftoff cultivation step should be taked, use phreatic water or running water pouring, have and select monitoring root nematode population, once find that namely root-knot nematode carries out killing line process, avoid the infection once again of root-knot nematode; The country strict to European Union, the U.S., Canadian quarantine request, again should change before outlet through quarantine, the cultivation medium of disinfecting, guarantee not carry any pest comprising root-knot nematode;

Biological control: carry out filling root with 20.0 ~ 100.0 mg/kg Avermectin virgin pulp liquids, the generation of prevention root-knot nematode, filled with 1 time every 15 days; If when finding that potted plant banyan root-knot nematode insect amount reaches 1 ~ 2 head/plant, Avermectin magma liquid irrigating root frequency should be strengthened, within 5 ~ 7 days, fill with 1 time, kill and control spreading of root-knot nematode; Use with a 10000000000/gram spore Paecilomyces lilacinus microbial inoculum alive rotation simultaneously.