What pesticides are used in grapefruit?

Every National Day, a large number of grapefruit are on the market in our country, which are very popular with people. At present, many parts of our country are planting, but during the planting period, there will be all kinds of diseases and insect pests. If you want to spray chemical control, what pesticides will be used to control the grapefruit?

1. Glue disease

Harm symptoms: harm the trunk and main branches, affect the tree potential, when serious, the disease spot expand "ring cut" the trunk, resulting in plant branches withered.

Prevention and treatment: first scrape off the rough skin of the disease department (now bluish yellow is appropriate), and then longitudinally cut several cracks, deep into the xylem, and then smear it with the tree protection general.

2. Foot rot (rotten scar)

Harm symptoms: mainly harm the neck of the trunk root, the bark at the base of the main stem of the damaged plant decayed, so that the yellow leaves withered branches, the tree potential weakened, the yield decreased, and when serious, the whole plant withered. The incidence is high in the high temperature and rainy season from July to August.

Prevention and treatment: scrape off the tissue of the disease department and burn it centrally. After shaving, apply the general to protect the tree. Spray treatment with 800 times liquid of new high lipid membrane in the early stage of the disease or in the absence of the disease.

3. Red spider

Harm symptoms: in order to harm leaves, fruits and tender shoots, the injured leaves show gray-white spots, and when serious, they are gray-white, lose luster, fall off early and weaken the tree potential. After the fruit is killed, it causes fruit drop, and the adult is nearly oval and dark red. Red spiders can do harm all the year round.

The overwintering harmful period of red spider is from February to March, the second peak period of red spider is from April to June, the low valley period of red spider is less from July to August, the climate is dry from September to November, the occurrence quantity is mostly the second peak period of red spider; the second peak is rainy for a long time, the second peak is in time for prevention and control, the pest population density is greatly reduced, and the second peak population density can be reduced with the decrease of spraying.

Methods of prevention and treatment: spray 2000 times of Kemate once in February, 2000 times of pyridazinone in April-May, or 2500 times of Tisuril in April-May, and 3000 times of Kemate in June. If the insect source did not reach a peak or the insect source was less than one leaf in September, the pesticide concentration was 3500 times, and the population density of red spider insects could be sprayed 1500 times after fruit harvest in the middle of November. If the orchard inspection of rare red spiders can not spray, waiting for mid-late December spray turpentine mixture will also be combined with the effect of killing red spiders.

4. Rusty spiders

Harmful symptoms: alias rust tick. Red flesh honey pomelo is a common and serious pest. Most of the reasons for the decline of pomelo orchards are rusty spiders that damage fruits and leaves. The surface of the fruits is brown, commonly known as "black bark", and leaves are easy to fall after damage.

Rust spiders like shade, afraid of light, mostly in the inner bore fruit, hanging branch fruit and fruit backlight damage, began to look like a layer of yellow powder, until the emergence of black fruit, even if spraying to kill the rust spider, the black skin is irreversible. It is generally transferred to young fruit damage and mass reproduction from late April to early May, which is the key to spray control.

The methods of prevention and control were 1-2 times in early May, mid-June and late July, respectively, and one in time in late August. Pesticide 80% Dysen zinc 500x liquid, isocarbophos 1000 times liquid. Choose a mixture of other insecticides. Moderate pruning to prevent excessive concealment of the crown and improve the ventilation condition of the orchard.

5. Phoenix butterfly

Harmful symptoms: Phoenix butterflies lay eggs at the tip of tender leaves, and the larvae (also known as big head worms) bite on the tender leaves of red flesh honey pomelo. When they are big, they can eat up the whole leaves, spend the winter with pupae on fruit trees, and become feathered after warm spring. For seriously damaged shoots, only petioles and midrib are left. if the larvae are disturbed, they protrude the horns of the stinky glands and give off fragrance.

Control methods: the common pesticides are 40% dimethoate 1000 times liquid, 90% trichlorfon water agent 800 times liquid, 80% dichlorvos 1000 times solution.

6. Scale insects

Harmful symptoms: the common ones in pomelo orchard are brown garden scale, sagittal scale, wax powder scale, blow cotton scale and so on. Mainly nymphs and female adults cluster on leaves, fruits and branches to absorb plant juice, which does great harm to red flesh honey pomelo. The damaged plants have poor growth, such as yellowing of leaves, early drop of leaves and fruit, which will seriously wither and die and reduce the economic value. Scale insects like to shade the environment, and their branches and leaves are too dense, which is beneficial to their survival and reproduction.

① brown garden scale: purple brown, edge light brown, central uplift, insect body yellow. In order to harm the branches and fruits of pomelo trees, they are often stacked on the branches and leaves. The annual occurrence of brown garden scale is about 5 generations. The nymph stage of the first generation in the middle and late ten days of April, the nymph stage of the second generation in June, the nymph stage of the third generation in the first and middle of August, the nymph stage of the fourth generation in late September, the nymph stage of the fifth generation in the middle and late December and before the third generation were controlled in time, and the occurrence of the fifth generation was less. Brown garden scale control 5, 6, 7 is the first generation, the second generation nymph stage, it is necessary to focus on better control effect, each generation control to master the first instar nymph control period.

② sagittal scale: purplish brown with grayish white edges. Male scale insects are all white, female shells are arrowhead, purplish brown, and the edges are grayish white. The sagittal scale has three generations a year, the nymph stage of the first generation in the first and middle of May, the nymph stage of the second generation in mid-late July, and the nymph stage of the third generation in early September.

③ wax powder scale: the female adult is oval and flat, covered with coarse white wax, and exudes reddish-brown liquid when the worm is pressed. Nymph back covered with white waxy powder, wax powder scale, 5 generations a year. A few nymphs hatched in the first ten days of April, the nymph stage of the second generation in the middle of April, the nymph stage of the second generation in the middle of June, the nymph stage of the third generation in the first and middle of July, the new shoots and leaves of the second generation were damaged, and attention should be paid to control from June to September.

④ cotton scale: the female is oval, raised on the back, the body is reddish brown, there are white powdery and slender wax filaments on the body, and white oocysts are secreted from the abdomen when spawning. There are three generations of cotton scale in a year, the nymph stage of the first generation in early May, the nymph stage in the first and middle of July and the nymph stage of three generations in late September. The time of control should be caught by spraying in the nymph stage.

Control methods: from May to September, choose a pesticide: scale killing special 1000 times, isocarbophos 1000 times, malathion 700times, 20% amitraz 1000 times, quick culling 700times (for autumn use), spray 15-17 times of turpentine mixture from mid-late ten days to mid-late January of the following year. Turpentine mixture is an effective agent to control scale insects in winter. Turpentine mixture has strong alkalinity and can corrode the wax of scale insects, and its stomata are occluded after application. It has a control effect on aphids, red spiders, rust spiders, coal fouling disease, lichens and moss.

7. Leaf miner

Harmful symptoms: leaf miner is the main pest in nursery and young trees, especially in summer and autumn. The larvae drill under the epidermis of tender stems and leaves to form a silver-white curved tunnel, and the injured leaves are curled or hardened and easy to fall off. the resulting wounds are often immersed in canker disease. The damage was serious from May to September. The tip of pomelo was sprayed every 5-7 days from 0.5 cm for a total of 3-4 times.

8. Longicorn beetles

Harmful symptoms: longicorn beetle larvae lurk in the trunk to become worms from April to May and often come out at noon to mate and lay eggs on the trunk about a foot above the ground. After hatching for about ten days, the newly hatched larvae eat the bark, then gradually eat the xylem and roots inward and downward, and turn to the upper trunk in September.

Prevention and control methods:

① capture: after the first ten days of May, all kinds of longicorn beetle adults come out of the hole one after another and mate to lay eggs. The adults should be caught around the tree trunk at noon on a sunny day.

② scraping off eggs: the Beginning of Summer is the period when adults lay eggs. You should often inspect the orchards and check the tree trunks a foot above the ground. If you find that there is saliva secreted, it is the place where eggs are laid, and you can dig up and destroy the eggs with a knife. Use medicine to plug and inject wormholes or hook larvae; often find wormholes in the tree trunks, eliminate insect droppings in the holes, plug the hole with cotton balls with 10 times the liquid of dichlorvos, and then seal the hole with wet mud to kill the larvae. Strengthen garden management. Combined with pruning, timely pruning and treatment of insect withered branches; weak trees are vulnerable to longicorn beetles, so forest management should be strengthened to promote vigorous growth and reduce the harm. Monochamus alternatus and other species like Monochamus alternatus do harm to dying or dead trees. Every year, before adults fly out, they are cut down in time to thoroughly clean up and deal with dead trees in the forest.

9. Pentatoms

Harmful symptoms: adult bugs and nymphs use needle mouthparts to insert into the fruit to suck juice, but also harm the branches and leaves. Causing many yellowish-brown wound spots. The adults overwintered (can live up to August of the following year) and began to lay eggs in April. The damage occurred from April to October, when there was sweetness from July to August, the damage was serious, and the piercing wound was not obvious at the initial stage, and then appeared gradually.

Prevention and treatment methods: ① captures adults and removes egg blocks. When the ② fruit begins to expand rapidly, it is sprayed several times to protect the fruit, and then at least once a month. It can use 1000 times of trichlorfon, 1000 times of omethoate, 2000 times of Pepsi, or 52.25% of 1500 times of Nongdile, etc.

10. Bridge-building insects

Harmful symptoms: three generations of bridge worms occur every year, the first generation is 1-2 instar from late April to early May, the second generation is 1-2 instar in early July, and the third generation is 1-2 instar in early September. The larvae like to float with the wind or turn around the crown at night, and the food damage is serious in cloudy days.

Prevention and control methods: 800-1000 times of trichlorfon water and 500 times of fenitrothion EC. During the peak period of egg incubation, 7216 bacterial agent or Bt emulsion can be used, and 10 billion live spores / Bacillus thuringiensis wettable powder 500ml 1000 times can be sprayed.

11. Beetles

Harmful symptoms: the beetle is a pest, which mostly occurs in the orchard in the mountain area, which is harmful to the newly planted red flesh honey pomelo tree. adults can not only harm the tender leaves of young trees, but also damage flowers and young fruits. The first generation of one year, from the first and middle of May to the middle of July, is the peak period of adults.

Control methods: 1000 times of trichlorfon, 1000 times of dichlorvos and 1000 times of malathion were sprayed on the leaves.

12. Aphids

Harmful symptoms: one of the main pests caused by aphids to tender shoots in spring, summer and autumn. In order to cause leaf wrinkling and curling of tender shoots, its secretions can rust and cause soot disease, inhibit growth, spread virus and cause Huanglong disease.

Control methods: 50% malathion 700x liquid, 80% dichlorvos 1000 times liquid, each time slightly longer 0.5cm spray 1-2 times. Combined with pruning, the residual flowers, diseased branches and leaves that are inhabited by aphids or latent eggs are thoroughly removed and burned.