Recently, the author visited the countryside in Guangxi and found that many orchards have sporadically appeared citrus lice, but in the first two years, it was rarely seen, why does this happen? This actually shows that citrus psyllids have a serious trend year by year, and growers should pay more attention to it and take the initiative to prevent it in advance.
Citrus psyllid on the back of the leaf
In fact, when it comes to citrus psyllid citrus yellow dragon disease, everyone will definitely think of citrus yellow dragon disease, because citrus wood lice is the most important medium for spreading yellow dragon disease, as far as the picture is taken, this is the citrus yellow dragon disease tree that the author photographed in 18 years, the most obvious feature is that the new shoots and young leaves outside the canopy grow upright upwards and do not turn green, and slowly turn yellow in the later stage; at the same time, the "red nose fruit" produced by the yellow dragon disease tree The author personally tasted, the taste is sour, and there is a bit bitter to lose the commodity value. Of course, the most important point is that huanglongbing disease must be removed after there is no cure for the disease, and a tree needs to be planted and cared for more than three years to hang fruit, which is a huge loss for farmers.
In addition to the transmission of citrus yellow dragon disease, citrus psyllids will also cluster on the young leaves of citrus new shoots for prickly feeding, resulting in premature aging of new shoots, curling and growth stagnation, and when severe occurrences, the honeydew in their excrement will cause soot disease to cover the leaves Affect photosynthesis Aggravation weakening tree potential increased hazard.
Yellow dragon disease tree and yellow dragon disease fruit
< h1 class="pgc-h-arrow-right" > why have citrus psyllids appeared so frequently in recent years? The author believes that there are mainly the following reasons</h1>
1, the low price of citrus coupled with high temperature and drought abnormal fruit drop, many orchards have become unmanaged orchards
Guangxi citrus prices have been in a downturn for the past two years, coupled with the emergence of this year's epidemic, many citrus slow selling prices are even more unbearable to look at, and finally many people are still at parity or loss of money to deal with it, which makes some people lose confidence in planting citrus to get rich and begin to cut down trees or abandon the garden; 19 years of sluggishness thought that 2020 would be good, who knows that the high temperature and drought weather that appeared some time ago aggravated the shedding of young fruits, and many citrus orchard orchards have fallen out of nothing, which makes the original sluggish citrus like " Worse" has been made, and more unmanaged gardens have emerged. Once the orchard is out of control, it will attract a large number of diseases and insects, especially citrus wood lice, and once the orchard is out of control, it will explode, and the orchard next to it will suffer.
2, the summer shoots can not control and a large number of pumping attract and provide rich food for citrus wood lice
In the first half of this year, the temperature is relatively abnormal, guangxi citrus area as a whole can not control the summer shoots and a large number of withdrawals, once the summer shoots are not only robbed of nutrients with the young fruits and cause the fruit to fall off abnormally, but also to attract a large number of diseases and insects, especially citrus lice They like to eat the young parts of the citrus and lay eggs in it, a large number of summer shoots are equivalent to giving citrus psyllids to improve the rich feeding material and aggravate the occurrence of psyllids.
3. The popularity of citrus cover film to keep trees fresh and failed to clear the garden in time
In the citrus area of Guangxi sugar orange is the largest planting area of citrus varieties, although the sugar orange market time coincides with the Spring Festival, but due to the oversupply many people choose to cover the film to keep the tree fresh to extend the harvest period to stagger the peak of the listing, which leads to many people have no concept of winter garden, so that the citrus can not be harvested in time in winter and timely garden, which makes citrus lice have the opportunity to successfully overwinter, and then aggravate the occurrence year by year.
Cover the film to keep the tree fresh
< h1 class="pgc-h-arrow-right" > what are the habits and characteristics of citrus psyllids? Only after understanding clearly can prevention and control measures be better formulated</h1>
1, good migration: citrus psyllids have the ability to fly migration, its adults can not stop for 50 minutes continuously, in 3 days to migrate 100 meters for 12 consecutive days can migrate 2 kilometers, so it has a good ability to migrate hazards.
2, prefer yellow-green: adults of citrus psyllids still have a certain preference and tendency for natural light color, they like orange-yellow and yellow-green similar to citrus reflective light, so they will be so "fond of citrus".
3, with tenderness: adults of citrus psyllids especially like to eat the new shoots of citrus and generally do not harm the old leaves, so every time the citrus draws new shoots and young leaves, they will flock to spawn and feed, and after the new shoots are ripe, they will return to the yellow bark tree or the nine incense next to the orchard for parasitic life.
4, diurnal nocturnal: citrus psyllids have obvious diurnal nocturnal characteristics, in the daytime they will generally hide and roost, in the evening will begin to come out of the activity, so in the evening drug prevention and control is the best control period.
The current difficulties in the prevention and control of citrus lice: The reason why citrus lice are difficult to control is mainly because large-scale unified control cannot be implemented in nearby orchards, so it is easy to transfer the harm of citrus lice and cause serious generational overlap and increase the difficulty of prevention.
Day and night out
<h1 class = "pgc-h-arrow-right" > although the citrus pyllid is harmful and has a serious feeding year by year, but it is preventable and controllable, and the fruit farmers should strengthen the basic work of agriculture to cut off their grain, destroy it and seize the 4 key nodes of medication in order to effectively reduce the occurrence of citrus pyllids</h1>
1, reduce the source of food for citrus psyllids, that is, cut off its grain
First of all, it is necessary to carry out scientific and reasonable fertilization of citrus trees, especially to reduce the use of pure compound fertilizer with the mode of organic fertilizer and microbial bacterial fertilizer, which can not only improve the pH of the soil but also promote the robust growth of citrus roots; and then learn to apply appropriate amounts of fertilizer according to the tree potential and growth period when topdressing, and pay attention to the supplement of medium and trace elements in order to cultivate robust tree potential and improve stress resistance.
Secondly, citrus psyllids like to eat new shoots and young leaves, so fruit farmers can use balanced foliar fertilizer + amino acid foliar fertilizer to promote the unified extraction of new shoots in addition to root fertilization when topdressing, and then when the young leaves of new shoots are about 20-30 cm long, they can use foliar fertilizer to spray ripening; if it is the summer shoots of hanging fruit trees, they should be erased in time, so as to reduce the time of citrus wood lice eating hazards.
Finally, it is best not to plant crops such as yellow bark trees or wolfberries near the citrus orchard, and at the same time, the nine incense sticks next to the orchard should be dug out in time, so as to reduce the source of food and living places for citrus wood lice, thereby reducing the occurrence of citrus wood lice.
The young leaves of the new shoots are well-pumped
2. Destroying the comfortable living conditions of citrus psyllids is destroying it
Citrus psyllids like to stay in a warm and dry environment for life, so the control of citrus psyllids is to destroy their most suitable living conditions, first of all, the orchard should be scientifically watered, especially in the case of continuous drought in the weather, it is necessary to water and cool down morning and evening while keeping the orchard well humidity can reduce the activity and reproduction of citrus psyllids;
Secondly, it is necessary to carry out reasonable pruning of citrus trees, and it is necessary to cut out the branches that do not bear fruit, the dense intersecting branches and the branches with serious pests and diseases in a timely manner, and at the same time to "open the skylight" to enhance the ventilation and light transmittance of the inner hall, so as to reduce the hiding and parasitism of citrus wood lice.
Then, for the fruit trees that can be harvested in time years ago, it is necessary to clear the garden in time, in addition to pruning the tree body, removing dead branches and leaves and diseased fruits, it is also necessary to use chemical agents, that is, high-efficiency insecticides and fungicides, to spray disinfect and kill the adult insects that have overwintered to reduce the harm of the next year; if it is an orchard that leaves the tree fresh in the cover film, it is necessary to use a safer insecticide fungicide before the cover film for disinfection, so as to effectively reduce the residue of citrus lice.
Finally, green prevention and control should be strengthened: for those who need to leave grass to moisturize in the orchard, green plants such as thistle or red thistle can be used to replace the planting of conventional raw grass, which can both cool down and moisturize and provide a living field for natural enemies of citrus psyllids such as grasshopper larvae and ladybird larvae to effectively control the occurrence of psyllids.
3. Grasp the best control node and use high-efficiency insecticides to prevent the outbreak of citrus psyllids
For the prevention and control of citrus pyllids, fruit farmers should strengthen the unified awareness of prevention and control, and the use of such as neonicotinoids of thiamethoxamine, acetamidine and parathrin bromothrin, bifenthrin and other agents combined with the egg killing ingredient pyridine ether for control, the key step is to seize the best control time node, so as to effectively control citrus pycnogenol.
There are 4 important time nodes for the control of citrus psyllids throughout the year, namely:
1. Winter garden clearing period: Citrus can use 10% cispermethrin suspension 1000 times or 40% chlorpyrifos emulsion 1000 times + 10% pyrithione suspension 2000 times to spray the whole park after winter fruit picking to the next spring before budding, which can effectively kill overwintering adults and reduce the spawning volume of late adults and reduce the hatching rate of eggs.
2. Spring shoot budding period: When the spring shoots are pumped to about 5 cm, generally from mid-March to early April, adult citrus pyllids begin to spawn in large quantities, at this time, 70% imidacloprid water dispersible granules can be used 3000 times + 10% pyrapropyl ether suspension 1500 times for uniform spraying, effectively killing adult insects and reducing egg laying.
3, the early stage of summer shoot extraction: in the summer shoot extraction to about 5 cm, generally from the end of the month to the end of June, the first generation of adult adults of citrus pyllid will lay eggs on the young leaves of the summer shoots, at this time you can use 70% thiamethoxine water dispersible granules 2000 times + 20% methion salt • pyripropyl ether suspension agent 2000 times for a uniform spray can effectively kill adult insects and eggs, reduce harm.
4, autumn shoot growth period: in the autumn shoots grow to 5 cm to the end of July to September, that is, from the end of July to September, this is the most serious period of overlap in the emergence of citrus pyllids and the most critical period of prevention and control, fruit farmers can use 40% biphenyl thiamethoxeramine suspension 2000 times or 10% cis cypermethrin suspension 1000 times + 10% pyrather · imidacloprid suspension 1000 times for uniform spraying, interval 10-15 days spray 2-3 times until autumn sativa, so as to effectively reduce the occurrence of citrus pychia lice.
Focus on the prevention and treatment of eggs
All in all, according to the author's experience in the citrus area for many years, it is found that citrus lice in Guangxi have a serious trend year by year, and fruit farmers should strengthen their attention to prevention and control, from the management to pay attention to the prevention and control of agricultural basics and fully rational use of chemical agents to seize the 4 key nodes of the year for auxiliary prevention and control, so as to avoid the old road of guangdong sugar orange destruction.