What pesticides are better for growing mandarin oranges?

Mandarin orange is a kind of orange with a very sweet taste. It mostly comes on the market around National Day, and the price is not expensive. It can not only be eaten directly, but can also be made into canned food. Many regions in our country grow it, so what pesticides are used for mandarin oranges?

1. Citrus canker

Occurs from April to August during the young fruit stage and new shoot growth stage. It damages leaves, branches and shoots, and fruit.

Control methods:

(1) When clearing the orchard in winter, thoroughly prune away diseased branches and diseased leaves; diseased leaves, diseased branches, and diseased fruit that appear in summer and autumn should also be removed.

(2) During the spring, summer, and autumn shoot emergence periods, spray when the leaves have not yet unfolded. You can spray 50% Tuzet wettable powder at 500-800 times dilution or 50% Thiophanate at 100 times dilution.

2. Anthracnose

Can occur throughout the year, damaging leaves, fruit, branches and shoots, and flower buds.

Control methods:

(1) Strengthen cultivation management to enhance tree vigor, and pay attention to drainage.

(2) Clear the orchard in winter, prune away diseased branches, and remove fallen leaves and fallen fruit on the ground.

(3) For chemical spraying, you can use 0.5% Bordeaux mixture or 50% carbendazim at 800-1000 times dilution.

3. Scab

Mainly damages young branches, leaves, and young fruit. When leaves are infected, water-soaked small spots first appear, then turn waxy yellow. After fruit is damaged, many tumor-like protrusions often grow.

Control methods:

When spring buds swell to 1 cm, spray 50% Tuzet at 500 times dilution or 70% Thiophanate-methyl at 800 times dilution. The second time, at the end of flowering, spray 70% Thiophanate-methyl at 800 times dilution.

4. Huanglongbing

Main symptoms: In addition to the appearance of yellow shoots, the main features for identifying this disease are: yellowing at the base and edges of leaves, with irregular mottled leaves alternating yellow and green.

Control methods:

(1) Choose disease-free seedlings and plant in isolated disease-free areas.

(2) Strictly control the disease transmission vector, the citrus psyllid. During each young shoot period, use insecticides to control the pest and protect the shoots, spraying omethoate at 1000 times dilution, Aphid-Citrus Psyllid Net at 2000 times dilution, and imidacloprid at 2000 times dilution.

(3) If diseased trees are found, dig them out promptly to eliminate the source of disease.

5. Foot rot

Drain promptly, improve light transmission and ventilation conditions in the orchard, and strengthen control of longhorn beetles and other trunk pests; select disease-resistant rootstocks such as trifoliate orange, citrange, and fragrant orange. For already infected plants, disease-resistant rootstocks can be used for rootstock replacement. Chemical control: after scraping off the diseased spots, apply medicine. Commonly used medicines include carbendazim and Thiophanate-methyl.

6. Mites

Citrus red mite, four-spotted yellow spider mite, and rust mite

Before and after flowering (March-May) and autumn (September-November) are the key periods for controlling red mites: control is needed when the mite population density before flowering reaches 1-2 per leaf, and after flowering and in autumn reaches 5-6 per leaf. The spring shoot emergence period, young fruit period, and fruit enlargement period are the main periods for controlling rust mites: when rust color first appears on the undersides of current-year spring shoot leaves; control immediately when the mite population density on leaves or fruit reaches 2-3 per leaf. Commonly used pesticides include hexythiazox, pyridaben, propargite, bromopropylate, and amitraz. Pay attention to protecting natural enemies such as long-beaked mites, blunt mites, predatory ladybirds, Japanese square-headed beetles, and green lacewings.

7. Scale insects

Arrowhead scale, red wax scale, cottony cushion scale, etc.

Key periods for chemical control: the nymph stage for arrowhead scale, the larval stage for red wax scale when large numbers climb onto shoots to cause damage (generally from early to mid-May to mid-June), and the peak larval stage for cottony cushion scale. Commonly used pesticides include buprofezin, methidathion, matrine + nicotine, chlorpyrifos, and mineral oil emulsion. Pay attention to improving ventilation and light transmission conditions in the orchard; protect and utilize natural enemies such as Japanese square-headed beetles, red-spotted ladybirds, green lacewings, golden aphid wasps, Australian ladybirds, and large red ladybirds.

8. Aphids

When the damage rate to new shoots reaches 25%, spray pesticide immediately for control. Commonly used pesticides include acetamiprid, dimethoate, and aldicarb. Attention should be paid to protecting seven-spotted ladybirds, large green lacewings, hoverflies, aphid wasps, etc., and pruning away overwintering eggs to reduce the pest population base.

9. Leafminer

The key control period is the summer and autumn shoot emergence period (early to mid-July). Promptly remove sporadic summer and autumn shoots that emerge, and combine with fertilizer and water management to promote robust and uniform new shoots. Chemical control: spray when new shoots emerge to 1-2 cm, once every 7-10 days, for 2-3 consecutive times. Commonly used pesticides include abamectin, cartap, and cyhalothrin.

10. Longhorn beetles

From May to August, manually capture and kill adult star longhorn beetles and green citrus longhorn beetles at noon on sunny days, and capture and kill adult brown longhorn beetles in the evening; promptly remove eggs, newly hatched larvae, and prune away damaged branches and shoots; soak cotton or cotton yarn with undiluted insecticides such as dimethoate and plug the insect holes, then seal the insect holes with mud to poison and kill the larvae.

11. Citrus blossom midge

At bud emergence, choose trichlorfon powder, diazinon granules, etc., mix evenly with fine soil, and broadcast on the soil surface under the tree canopy, once every 7 days, for 2-3 consecutive times; when flower buds are 2-3 mm in diameter (when turning white), choose parathion, trichlorfon, etc., to spray the tree canopy; remove damaged flower buds as early as possible, and bury them deeply or boil them; deeply plow the orchard soil in winter to eliminate some overwintering pest pupae.