How to control black spot moth?

Bark borer, commonly known as scarab, belongs to LEPIDOPTERA and ladybug, and occurs in jujube trees in China. Miscellaneous eating habits, but also harm pears, apples, apricots, willow, elm, Robinia pseudoacacia, Toona sinensis, poplar and so on. From 65438 to 0995, Yang Zhenjiang and others studied the biological characteristics and control of the insect, which was identified by Mr. Song Shimei from the Institute of Zoology, Chinese Academy of Sciences and named skin spot moth.

(1) ① Morphological characteristics of adults. Body length is 6.0 ~ 8.0 mm, wings spread 13.0 ~ 17.5 mm, all gray to black gray. The lower lip must be gray and upturned. The antenna is dark gray and filiform, which is about 2/3 of the length of the front wing. The compound eye and chest and back are dark gray, and the ventral surface and abdomen are gray. The front wings are dark gray to dark gray, with two white wavy horizontal lines and dark gray wide edges. The marginal hairs are dark gray, the hind wings are light gray, the outer edge is slightly dark, and the marginal hairs are light gray.

Two eggs. Oval, 0.5 ~ 0.55 mm long and 0.35 ~ 0.4 mm wide. It is milky white in the early stage of spawning, red in the middle stage, dark red to black red when hatching, and the eggs are covered with honeycomb reticulate patterns.

When the larvae are first hatched, their heads are light brown and their bodies are milky white. The mature larvae are 10 ~ 16 mm in length, grayish brown and slightly flat. The head is brown, the chest back plate is dark brown, the hip plate is dark brown, and there are 5 pairs of abdominal feet. The third to sixth gastropods are toe hooks with 26 ~ 28 toe hooks. Hip-toe hook with double sequence middle band, toe hook 16 ~ 17.

The pupa is 5.5 ~ 8 mm long and the chest width is 1.3 ~ 1.7 mm. It is light yellow in the early stage, brown in the middle stage and black before eclosion (Figure 27).

Figure 27. Black spot moth

(2) A brief history of life history: 1 year has 4-5 generations in Cangzhou. The fourth generation larvae and the fifth generation larvae overwinter alternately, with overlapping generations. Larvae overwinter near the damage, start to move in late March of the following year, pupate in early April, overwintering adults begin to emerge at the end of April, and the first generation of eggs and larvae appear in early May. The first and second generation larvae harm the nail mouth of jujube tree, making it unable to heal, making the tree weak, falling flowers and fruits, and even causing jujube tree death in serious cases. Some mature larvae of the fourth generation do not overwinter after late September, and the fifth generation overwinters in mid-June165438+1October.

(3) Prevention and control methods ① Agronomic measures: scraping skin in spring, focusing on removing the warping skin around the nail opening and eliminating overwintering cocoons and larvae.

② Drug control: Spraying 5 waves of meishi sulfur mixture before jujube tree germination, focusing on nail opening. Use 40% acephate EC 100 ~ 200 times, or 40% acephate EC 100 ~ 200 times, 2.5% kung fu EC 500 times, or 40% Lethburn EC 100 ~ 200 times, 20% pozzolana.

Expert case (1) The winter jujube trees planted in a rural area of a city in the spring of 198 are about 10 hectares, and 200 1 year is still abnormal. What is the reason?

In the spring of 2002, the author was invited to make an investigation.

Basic situation of orchard planting: Dongzao orchard was partially subsidized by the municipal government to mobilize farmers to plant in the tide of agricultural structural adjustment. At that time, in order to improve farmers' enthusiasm for planting winter jujube, town and village leaders led some farmers in the village as representatives to visit and study in Shandong and Hebei winter jujube producing areas. Seeing the rich experience of farmers planting winter jujube in jujube area in the past two years, visitors are full of confidence. After returning to the village, they mobilized the farmers in the village to plant winter jujube about 10 hectare with a planting density of 3 meters ×4 meters. The garden is located in the suitable area of winter jujube, and the soil is loam with slight salt and irrigation conditions. The survival rate of winter jujube planting is about 80%, and there are plots lacking seedlings, which have poor growth and basically no yield.

Through investigation, the author thinks that the winter jujube orchard in this village is designed as the middle crown of planting density of 3 meters ×4 meters, and it is normal that it cannot form economic output after three years of planting. Because the yield of orchard is determined by the number of branches per hectare and the leaf area coefficient (leaf area coefficient is the ratio of the sum of all leaf areas of fruit trees to the land area occupied). A large number of studies show that when the leaf area coefficient reaches 4 ~ 5, the number of branches per hectare is the best, the tree structure of fruit trees and the group structure of orchards are reasonable, with good ventilation and light transmission, the highest productivity and the best economic benefits; When it is less than 4, the number of branches is small and the yield is low; When it is higher than 5, there are many branches, and the ventilation and light transmission of crown and orchard are poor. Although the temporary yield will be higher, the fruit quality is poor and the overall benefit is not high. 2 ~ 3 years after planting, the growth of jujube orchard can't meet the requirements of flowering and fruit setting, but the growth of trees should still be promoted, so it is normal that the orchard has no economic output for 2 ~ 3 years after planting. In order to bear fruit after two years of planting, it must be a close planting jujube garden or a planned close planting jujube garden. Because farmers don't understand this, the original expectations are too high, and they lose confidence after planting for two years. Some farmers have the idea of planing trees. Therefore, management can't keep up, pests and diseases are serious, and the growth of trees is small, so it is difficult to achieve early results. The key of this orchard is to improve farmers' understanding, enhance the enthusiasm of managing jujube trees, and implement various technical measures such as fertilization, watering, pruning and pest control to achieve the expected goal as soon as possible. Therefore, the author conducted technical training for farmers in the whole village. First of all, the reason why the garden does not bear fruit is analyzed, so that farmers can realize that it is not that the winter jujube tree does not bear fruit, but that the planting form cannot bear fruit early. Therefore, management should be strengthened to create conditions for the results as soon as possible. After that, the domestic and international markets and development prospects of winter jujube were analyzed for farmers, which improved their understanding level, strengthened their confidence in managing winter jujube and mobilized their enthusiasm in managing trees. On this basis, the pollution-free cultivation techniques of winter jujube were expounded, and the solutions were put forward in view of the problems existing in the park.

① Increase the application of organic fertilizer. Each plant is not less than 25 kg, and furrow application is adopted to deepen the active soil layer, improve the soil structure and physical and chemical properties, and improve the ability of water and fertilizer conservation. Before germination, topdressing and watering, topdressing urea and diammonium phosphate 0.5 kg per plant, shaking for many times before rainy season to preserve moisture, inhibiting soil alkalization, planting green manure in rainy season to solve the problem of insufficient source of organic fertilizer.

② Replanting the plots lacking plants.

③ Fixed stem shaping. When the diameter of winter jujube trunk reaches 2 cm, it is fixed and dried, and delayed open-heart trees are adopted according to the planting density of the garden. When pruning in winter and summer, it is necessary to maintain the growth advantages of elongated branches at all levels, exclude the overgrown branches that have a bad growth position and affect the growth of trees, and let other branches go slowly. By pulling and twisting branches, the growth direction and trend can be changed and the transformation to reproductive growth can be promoted. At flowering stage, the temporary auxiliary branches and fruiting basal branches of the whole tree were circumcised in multiple ways, and 920 +0.2% urea +0.2% 20mg/kg was sprayed. After 10, the foreskin was circumcised again, and topdressing was applied at the fruit expansion stage 1 time, and 200 grams of diammonium phosphate and 200 grams of potassium sulfate were applied to each plant. In 2003, a good harvest of 3 kg of winter jujube per plant was obtained. Seeing promising farmers, the enthusiasm for managing trees has further increased. It is estimated that in two years, the trunk will be about 8 cm thick, the whole tree will be open when the plants are about to meet, and the garden will enter the fruiting period.

(2) Why did a village plant 3 hectares of winter jujube in the spring of 2003, and the survival rate was less than 50%?

The author went to investigate, and the reasons for the low survival rate are:

(1) There was no soil preparation before planting winter jujube. Now we are digging a pit to plant trees, and the planting pit is small. Because there is no water source in this land, the winter jujube was watered twice after planting, so there is little water and the soil is dry and short of water.

② Winter jujube seedlings were transported far away. After being transported to the village, the roots were not soaked in water, but planted in the village Committee the next day, resulting in excessive water loss for the seedlings.

(3) The quality of seedlings is poor, the root width of seedlings is larger than 10 cm, and the lateral roots are few, so effective preservation measures have not been taken.

(4) Under the above circumstances, when planting winter jujube, the aboveground part of the seedlings was not cut short and the secondary branches were not drained, resulting in imbalance of water supply between the aboveground part and the underground part, which inevitably led to low quality and survival rate of planting trees.

There was little rain in the spring of 2003, and it didn't rain until July 8, which is one of the reasons for the low survival rate.

Planting trees looks like a simple thing, but it's actually not simple. It is a systematic project, involving environment, soil, seedling treatment, planting technology and post-planting management, and it is the basis for the country to incorporate tree planting into engineering afforestation. Through practice, the author thinks that in order to improve the survival rate of afforestation, we must first improve the ideological understanding of the ranger and let him realize that he is planting trees for himself and for his own survival, and he must have a sense of responsibility. On the basis of raising awareness, do a good job in planning and design before afforestation, soil preparation and fertilization, strictly control the quality of seedlings, and ensure that seedlings do not lose water as much as possible from emergence to planting. Before planting, the roots and trunks of trees should be trimmed and soaked, and seedlings should not be planted too shallow or too deep (except for tree species whose branches are easy to take root). They should be watered after planting. For example, it is difficult to prepare a big pit in a plot that is difficult to water, and it is necessary to dig a small pit (subject to the stretching of the root system) for planting. The author experienced that under the same conditions, when planting winter jujube, the trunk 1/3 ~ 1/2 was cut and all the secondary branches were drained, and the survival rate reached 98%, while the trunk was not cut and drained twice, and the survival rate was only 60%. It is very important to soak the roots before planting. Under the same conditions, the survival rate of roots soaked in clean water 12 hours is 32% different from that of roots not soaked. Under the same conditions, after planting, watering, and then each plant covered with plastic film 1 m2 is about 20% higher than that without plastic film, so the winter jujube covered with plastic film germinates neatly and grows vigorously. Therefore, it is not difficult to correctly master all technical links of tree planting and make the survival rate of tree planting reach over 90%.

(3) A farmer 10-year-old winter jujube tree in a village was stripped of the bark in the middle of the trunk in spring, and the author was asked to provide remedial measures for field inspection. It was found that the width of cut bark was between 10 ~ 15cm, reaching xylem, and the bark was not connected, so it was decided to bridge.

Firstly, farmers were asked to fertilize and water the cut jujube trees, and 300g diammonium phosphate was applied to each tree. The cut tree was plastered to smooth the wound, and then wrapped with plastic film to prevent water loss. The trees were covered with plastic film for 2m ~ 2 to keep moisture and raise the ground temperature. Then, healthy jujube heads were collected from other untrimmed winter jujube trees, the secondary branches on the jujube heads were removed, and the cuttings were cut into scions with the length exceeding the damaged skin 10 cm, sealed with paraffin wax, wrapped with wet cloth, put in the freezer (temperature 1 ~ 4℃), taken out and bridged, with 4 scions per plant. A month later, after inspection, all the grafts survived, so the cut winter jujube tree was saved.

(4) Cause analysis and countermeasures of jujube fruit cracking and rotten pulp From the end of August to the end of June, 2003, jujube fruit was expanding and maturing, and continuous rainfall in Cangzhou caused great losses to jujube production. The fruit cracking rate and rotten meat rate of jujube are generally around 50%, seriously above 70%, and the rotten fruit rate of late-maturing winter jujube is also around 20%. The reason is that frequent rainfall is the direct cause of jujube maturity. According to incomplete statistics, it rained 14 times during this period, with an average of 3-5 days 1 time, and the accumulated rainfall exceeded 500 mm, which is the annual average rainfall in Cangzhou. More rainfall, less sunshine, weak photosynthesis, less dry matter accumulation and high water content of jujube fruit are suitable for pathogen propagation and infection. In addition, it is also related to varieties and cultivation management level, so the author made a special investigation. Through the investigation and analysis of jujube orchards in 12 villages, more than 50 different plots and different management levels, the main reasons of jujube cracking and pulp rot are as follows:

(1) is related to varieties. The number of cracked fruits varies greatly among different varieties. For example, the fruit cracking weight of jujube is above 80%, and other varieties are lighter, and the fruit cracking of winter jujube is about 10%. The fruit cracking degree of jujube is also different. The strains with early maturity, thin skin and good umami taste all have serious fruit cracking, up to more than 90%, and the fruit cracking of long body is lighter than that of small round body. The reason is that although they are all Ziziphus jujuba, many strains have been separated due to natural variation in thousands of years of cultivation history. According to the general survey of jujube resources in Cangzhou, there are more than 20 Ziziphus jujuba. In the past, the propagation of jujube trees mainly depended on roots and tillers, but did not pay attention to selection, thus showing individual differences.

② It is closely related to the management level when the varieties (strains) are basically the same. The general trend is that families with more organic fertilizers are lighter than those with only chemical fertilizers, and the fruits in the later stage are lighter. There is a jujube tree that specializes in raising cattle. Because cow dung is the main fertilizer every year, the cracked fruit and rotten pulp of this jujube tree are lighter than those of other farmers in the same village by more than 20%. Jujube trees applying organic fertilizer can obtain all-round nutrients, with good site conditions, reasonable soil physical and chemical structure, vigorous tree potential, strong photosynthesis ability and high dry matter content in jujube fruit, which is bound to have strong anti-cracking and anti-pith rot ability.

It is related to the depth of root distribution. In the investigation, it was found that most of the roots of jujube trees that adhered to the deep ditch fertilization method for many years were in the soil layer 40 cm deep. The root system is deeply distributed, absorbs nutrients in a large area, and the growth environment of the root system is relatively stable, showing strong tree potential and strong resistance, so fruit cracking and pulp rot are light; On the contrary, for farmers who have been applying fertilizers on the ground for many years, most of their roots are in the soil layer of 15 ~ 20cm, which is not only small in absorption area, but also not drought-resistant, cold-resistant and waterlogging-resistant. Poor root growth environment will inevitably lead to poor growth of the above-ground parts, affecting their own resistance, and fruit cracking and rotten pulp are inevitable.

This is related to the load. In the investigation, it was found that trees with many fruits not only have low single fruit weight, but also have serious phenomena of fruit cracking and pulp rot. On the contrary, it is light. This is mainly related to the nutritional status of trees. Trees with more fruits have poor nutritional status and less dry matter, which affects the resistance of fruits. In addition, insufficient nutrition of trees will inevitably affect the nutritional growth of jujube trees. Poor nutritional growth will weaken the ability to make nutrients, and the tree will be weak and have poor resistance. This is why high-yield trees must maintain a certain amount of nutritional growth every year.

It is related to whether watering is reasonable. Drought makes the fruit grow slowly, and sudden rainfall causes the fruit to crack because of uneven growth inside the fruit and between the peels, which is essentially caused by uneven water supply during the fruit growth. Therefore, timely and appropriate watering, underground plastic film mulching and grass mulching can reduce fruit cracking in dry season.

It is related to calcium deficiency. Calcium is an important component of cell wall, and calcium deficiency will aggravate fruit cracking. In recent years, most farmers reduce or basically do not apply organic fertilizer, which leads to the deterioration of soil structure and physical and chemical properties, calcium fixation in soil, which is difficult for roots to absorb, leading to calcium deficiency in fruits. In addition, in recent years, most farmers do not spray stone sulfur mixture before germination, and do not use Bordeaux mixture in rainy season, which reduces the opportunity of calcium supplementation. The author once sprayed with 0.2% calcium chloride solution and achieved good results. In the field investigation, I also saw that jujube trees sprayed with Bordeaux mixture had slight fruit cracking and pulp rot.

It has something to do with fruit sitting posture. Jujube fruits facing the sun in the upper part of the tree are easy to crack due to sudden rainfall, which is essentially caused by uneven water supply and growth.

To sum up, jujube fruit cracking is related to varieties, weather, water supply, tree nutrition, management level and many other factors. Fruit pulp rot is closely related to fruit cracking, which can increase the chance of pathogen infection and accelerate the onset and spread under suitable climatic conditions. The solution should start from the following four aspects:

First, improve the variety structure, by grafting big trees, turn the plants with poor fruit quality that are easy to crack into excellent plants, such as Jinsixiaozao No.4 (Dajinsi). We should also strengthen the selection of winter jujube to further improve its quality. In order to develop jujube trees in the future, we must use grafted seedlings, tissue culture seedlings or cutting seedlings of excellent single plants.

When the weather is dry, it is necessary to water the fruit in a timely and appropriate amount, balance the water supply, or cover the ground with plastic film or grass, so that all parts of the fruit can grow harmoniously and reduce fruit cracking.

By increasing the application of organic fertilizer and adopting scientific fertilization methods, the structure and physical and chemical properties of deep soil can be improved and the root system can be guided downward. Through reasonable topdressing, soil fertility can be improved, and the use times of 920 and other fruit-setting accelerators can be reduced, so as to achieve suitable results, promote tree vigor and improve the stress resistance of fruit trees themselves.

Do a good job in winter cutting and summer cutting, adjust the vegetative growth and reproductive growth of the whole tree, remove the long branches and auxiliary branches that affect the light conditions in time, and create an environment that is conducive to the accumulation of nutrients in the tree and is not conducive to the reproduction of pests and diseases. At the same time, fungicides are used from the end of June, bordeaux mixture is used for 2-3 times in rainy season, other fungicides are used after mid-August, and calcium is supplemented at the same time, and calcium is supplemented every 10 ~ 15 days until the fruit is ripe, which can effectively reduce fruit cracking and pulp rot. For the use of chemicals, please refer to the section on pest control. After mid-August, 2003, the author used Sheng Da M-45 and Nova alternately, and added 200 times of amino acid calcium and carboxymethyl cellulose (food grade), which achieved good results. Compared with the control (without cellulose), fruit cracking decreased by more than 65438 00%. Carboxymethyl cellulose is a film-forming agent, which can form a thin film when sprayed on fruits, and has a good effect on protecting fruits and prolonging drug efficacy (if it is food-grade carboxymethyl cellulose, it should be soaked in water 12 hours in advance to dissolve it, and then diluted).

(5) What causes the yellow and white spots on the leaves of the new shoots in the winter jujube orchard?

The author visited the jujube trees in this winter jujube orchard and thought that the iron in the soil was difficult to be absorbed by the roots because of the saline-alkali soil, which led to the physiological disease caused by iron deficiency-yellow leaf disease. The spot on the leaf is a spot disease infected by the poor disease resistance of the leaf under the condition of yellow leaf. It is suggested that farmers use 0.3% ferrous sulfate +0.3% urea +0. 15% citric acid solution to spray the whole tree and leaves, and use 50% chlorpheniramine 1000 times solution to prevent and control spot disease, correct yellow leaf disease and control its spread.

(6) Farmers in a village have 0.3 hectares of jujube trees. How to turn winter dates?

Because of the poor quality of jujube, this farmer wants to plant winter jujube, 13 years old. By abdominal grafting, all the branches with base diameter of 1.5 ~ 2 cm were cut off and grafted with winter jujube, and the whole tree was grafted with more than 50 winter jujube scions on average. The crown size basically recovered in that year, and it can bear fruit in the next year.

When I went to the countryside, I saw that some places were still continuing the old method of grafting new varieties on big trees. 10-year-old trees are very heavily shrunk to large branches with a diameter of about 10cm for grafting, and the whole tree can only graft 3-5 branches. This grafting method has slow crown recovery and late yield recovery, which affects farmers' income. The author suggests that it is best to change new varieties of big trees and adopt multi-head abdominal grafting to try to resume production in the next year. If the introduced variety scions are precious, we can concentrate on grafting 1 ~ 2 scions first, and then expand the grafting area in the second year, which will not only ensure the newly grafted jujube trees to resume production in the second year, but also minimize the temporary losses caused by replacing new varieties.

(7) Some farmers in a village have lost their buds before the jujube trees bloom, please help to remedy them.

Through field investigation, due to the lack of nutrition in tree storage, flower buds are poorly differentiated and thin, and the harm of green blind stinkbug leads to flower buds falling off.

The author suggested that the nail should be opened in advance (May 20th), the jujube head and secondary branches should be cored, the big auxiliary branches that affect indoor illumination should be removed, and the flower bud differentiation should be promoted by concentrated nutrition. Do a good job in the prevention and treatment of green blind stinkbug, and protect the leaves and new shoots. Grasping the sunny weather at flowering stage, spraying 15mg/kg 920 +0.2% urea solution +0.2% potassium dihydrogen phosphate solution +0. 15% borax solution twice achieved good results. There were no buds on the tree when the nail was opened. Through the above technical measures, more than 400 kilograms of fresh dates were produced per 667 square meters, reducing losses.

(8) The reasons and countermeasures of low fruit setting rate of Cangzhou winter jujube in 2004.

In 2004, the fruit setting rate of most winter jujube trees in Cangzhou City was very low. The author investigated and studied the representative winter jujube orchards, and thought that the main reasons were insufficient nutrition of trees, low rainy temperature in flowering period and the harm of green blind stinkbug were the important reasons for the low fruit setting rate. The main performance is:

① It was found in the investigation that the flower buds of Dongzao orchard with more fruits last year were poorly differentiated, mostly thin single-sequence buds, with weak resistance to external adverse conditions, serious flower dropping and low fruit setting rate. Most of the orchards that bear good fruit this year are 1 ~ 2-year-old young trees that did not bear fruit last year. There is a lot of rain this spring, which is beneficial to the nutritional growth of winter jujube. At this time, the leaves can't produce nutrients effectively. Nutrients consumed by vegetative growth come from the storage of nutrients in trees, and nutrients are not fully transported to reproductive growth, resulting in serious loss of flowers and fruits. For example, the fruit setting rate of jujube orchards with well-controlled jujube tree heads, secondary branches and hanging dates is higher than that of jujube orchards with poor control. Under the same conditions, the fruit setting rate of jujube trees with auxiliary branches is higher than that of jujube trees with auxiliary branches. According to the author's experiment, the fruit setting rate of hanging dates is 24% higher than that of the control (hanging dates without removing stones), which is consistent with the investigation results. In the investigation, we also saw a phenomenon that there is a winter jujube garden, and it is better to have only one winter jujube in the whole garden. The reason is that the tree is inclined, the branch angle is large, the tree is relaxed, and the reproductive growth and nutritional growth are balanced. To sum up, trees or gardens with low fruit setting rate all indicate that the main reason affecting fruit setting is nutrition. Because Dongzao is a variety with late fruit maturity, the leaves turn yellow and fall off after fruit picking, and the nutrient accumulation time is shorter than that of other fruit trees. Therefore, the storage nutrition of winter jujube is more precious and important.

② The low flowering temperature is an important reason for the low fruit setting rate of Dongzao jujube. Winter jujube needs a high temperature of 23 ~ 26℃ every day during flowering to facilitate pollination and fruit setting. In this year's flowering period, there were two low-temperature days (June 4-8 and June 16-20), and the average daily temperature was lower than 22℃ for five consecutive days, from June 1 day to June 25, and the average daily temperature was 23℃. Compared with the same period of last year, there was only one cold weather in the flowering period (June 9 ~ 14). From June/KLOC-0 to June 25th, the average daily temperature was 25℃, 2 degrees higher than this year. Last year's fruit setting was characterized by good fruit setting in the early and late stages, which was also consistent with the temperature. It is understood that last year, the winter jujube area in Shandong Province also affected fruit setting due to rainy and low temperature during flowering.

(3) The harm of green blind stinkbug is also an important factor for the low fruit setting rate of winter jujube. The damage of Aedes aegypti to leaves will affect the photosynthetic function of leaves and reduce the ability to synthesize nutrients. Damage to buds and young fruits will weaken the vitality of buds and young fruits, which will turn green in light and yellow and fall off in heavy cases. According to most experts' research, when the temperature reaches 10℃ and the air humidity reaches 70%, it is beneficial to the hatching of overwintering eggs in stinkbug. Since April this year, it has been rainy in Cangzhou, and the air humidity is much higher than last year, which has contributed to the occurrence of green blind stinkbug, and the leaves, buds and young fruits of winter jujube have been seriously damaged. In this year's orchard, the fruit-setting rate of winter jujube is far lower than that of the orchard with green blindness in stinkbug.

According to the analysis of the causes of low fruit setting rate of winter jujube, the solution should be based on strengthening the comprehensive management of soil, fertilizer, water and pruning, solving the problem of insufficient nutrition in tree storage through reasonable load and proper fruit setting, and then paying special attention to flowering management and pest control to ensure high quality and high yield of winter jujube. For technical measures, please refer to the relevant sections above.