Cloves are mainly pest control

1 disease of cloves

1.1 Dark spot disease

At the beginning of the disease, there are faded green spots on the leaves, which gradually expand to form round or nearly circular spots, 3 to 10 mm in diameter, brown or dark brown, with wheel lines but not obvious. The spots later become gray-brown, densely packed with black mold spots, which are the conidia and conidia of pathogenic bacteria. The patches are connected to each other so that a large part of the leaves are brownish yellow and die, and they shrink or even break. The pathogen of clove black spot disease is streptosporus fungi. Conidia stalk scattered or several root collections, brown; Conidia brown.

1.2 Brown spot disease

Brown spot disease mainly affects leaves, seedlings and adult trees can occur. Small spots appear on the leaves at the beginning of the disease, water-stained, nearly round, gray-green, 3 to 12 mm in diameter. When wet, small mold spots are scattered on it, and when it is severe, the spots are combined into large dry spots, gray-brown, covered with leaves, and look like fire from a distance, which will cause the lilac leaves to dry out, and eventually fall leaves early, leaving only a small number of leaves in the whole plant. The pathogen is a fungus of the genus Coccyx, which also infects camellia, pomegranate, populus macrophylla, purple weed, rhododendron and cockscomb flower.

1.3 Powdery mildew

The disease can occur on both sides of the leaf, which is predominantly frontal. At the beginning of the disease, sporadic small powder spots are produced on the diseased leaves, gradually expanding, the powder spots are interconnected to cover the leaf surface, and the white powder layer becomes sparse and dusty in the later stage of the disease, and the white dots appear on it, and finally become black dot powder - closed capsule shell, which is the sexual age of the disease, and the white powder layer is the asexual era. The disease of clove powdery mildew is caused by powdery mildew clove. The closed shell is spherical or oblate spherical, with several forks at the tip of the attached filament; Multiple ascomycetes in the closed shell, oval to broad oval; Ascospores are 4 to 6, oval or ovate.

1.4 Disc polysporus leaf spot disease

The spots are small round spots of 1 to 5 mm, with a dark brown white edge in the middle, accompanied by a purple halo, and when wet, the spots grow a large number of small black spots, and the spots penetrate both sides of the leaf. The pathogen is matricularis and polyspores. The black spots on the leaf spots are conidia discs, spindle-shaped, with 4 septa divided into 5 cells, 3 light brown in the middle, colorless at both ends, and long at the apex

3 flagellars.

1.5 Large stem spotted leaf spot disease

The spots are nearly round or irregular, with a diameter of 10 to 30 mm, and can occupy more than 1/2 of the leaf area when the spots are at their largest. The lesions are grayish brown, and there is a wavy purple-black stripe at the junction of the disease, on which a large number of small black spots are scattered, and the diseased leaves are deformed in the later stages. Pathogens invade mainly from the tip of the leaf. The pathogen is the theophyllum brown-spotted large-stemmed fungus. The conidia stalks are small and unbranched. Conidia are oval, unicellular, colorless, and are 15.5 to 17.5 μm in size× 3.8 to 4.2 um. The small black spots on the leaf spots are the conidia of the pathogen, flattened spherical, with a diameter of 100 to 120 μm.

1.6 Linear spore leaf spot disease

It has been reported in India. In the early stage, small water-stained spots appear on the leaves, up to 1 to 3 mm in diameter, with a yellow halo at the edges, the center is obviously white, and in most cases the spots are combined, and typical leaf rot symptoms appear, and the leaf tip withers up to half a leaf. The pathogen is a semi-chiculent Corynebacterium fungus, with conidia stalks erect and spaced, growing in bunches on the back of the leaf. There are branches, each branch can produce a bottle stem, and finally produce conidia, stick-like multi-septal.

1.7 times blight

The disease is mainly prevalent in Sumatra and other places, and it is not currently seen in China. After the disease, the bark and xylem of the branches turn reddish brown, which can produce small black spots, which grow yellow mucus on them, and make the surface of the diseased part rough, and the individual branches wither back, and when severe, the whole plant dies. The pathogen is caused by a fungus of the genus Cryptosporidium. This is a wound parasite, the pathogen conidia are scattered, with a long neck, conidia linear, yellow single spore can be clumped. The ascomycete is elongated without ancillary filament, and has 8 spores inside, spores filamentous, single-celled.

1.8 Bacterial blight

Clove bacterial blight, also known as bacterial spot disease, predominantly infects leaves [8]. There are four main types of symptoms on the leaves: first, spots, which begin to occur in the lower leaves, become faded green spots, soon become brown, and then the center of the spots is grayish white; The second is the star bucket spot, in which one or more brown lines are extended outside the circular disease spot and connected with other small spots to form a star bucket; The third is the flower spots, the spots continue to expand outwards, forming concentric wheel patterns, the center is gray and white, and finally a wavy line is born around the round spots, making the round spots resemble flower shapes; Fourth, the whole leaves turn brown, dry and curled up on the branches, and from a distance it looks like a fire, and when it is serious, the whole bush dies. The pathogen of the disease is bacteria, Pseudomonas lilac, pseudomonas pseudomonas. The body is solitary, rod-shaped, with 1 to 2 flagellar hairs at one end, which can swim in water without pods. Gram stain response is negative.

1.9 Algal spot disease

The lesions are nearly round or irregular, with a diameter of 5 to 12 mm, initially purple-red, then the center becomes purple-black, and its edges are still purple-red. A large amount of golden felt grows on the back of the lesion. The pathogen is a parasitic algae plant. Pathogenic algal nutrients spread on the spots to form dense, nearly round felt-like substances, which later grow sporangia and zoosporangia. The spore sporangia are enlarged at the tip, and there are 8 to 12 small stems on it, each of which grows an ovate, yellow-brown zoosporangia at the top, and when mature, it releases double flagellar and oval zoospores when wet.

1.10 knot nematode disease and root rot

It is a root disease. Nematodes can cause weak plant growth, yellowing of branches and leaves, and root knots at the roots; Root rot, on the other hand, rots at the roots. Light ones stop growing, and heavy ones wither to death.

<h2 class= "pgc-h-arrow-right" >2 clove infestation</h2>

2.1 Ticks

There are many varieties of insects that damage cloves, such as blowing sponges, guard spear arrow tip bugs, etc., insect pests first damage the branches of cloves, causing leaf wilting and black mold spots on the branches.

2.2 Leaf-diving jumping nails

The latent leaf jumping nail, also known as the Privet lady jumping nail, belongs to the coleoptera leaf nail family, mainly harmful lilac. In North China for 3 generations per year, adults mainly eat leaf flesh pieces, resulting in round or irregular small spots on the leaves, while the larvae dive into the leaf epidermis to drill moths, forming curved submersible worm tracts in the epidermis, resulting in leaf damage and a large number of leaf scorching.

In addition, pests that harm cloves include aphids, leaf moths, etc.

<h2 class= "pgc-h-arrow-right" > 3 Control and management of clove pests and diseases</h2>

3.1 Chemical control

In early spring, spray Bordeaux liquid, zinc desen, stone sulfur compound and other protective agents in advance for prevention and control. Spray fungicides such as bacillus and carbendazim in time after the onset of the disease, or spray 50% methylthiopyridine 800 times liquid every 15 days after the clove leaf spread, or use 50% carbendazim wettable powder 1000 times liquid for prevention and control, spray 2 to 3 times. It is also possible to spray 1:1:150 times Bordeaux liquid before or at the beginning of the disease to maintain new leaves and increase disease resistance.

For the prevention and control of bacterial diseases, 3% mesophytein wettable powder 600 to 800 times liquid, or 2% chlormycin wettable powder 300 to 500 times liquid, or 60% succinacetin aluminum wettable powder 500 to 700 times liquid, or 20% leaf subizubizole wettable powder 600 to 800 times liquid, or 30% copper succinate wettable powder 400 to 600 times liquid for prevention and control. When the disease is common, 72% agricultural streptomycin sulfate soluble powder 2000 to 4000 times liquid, or 88% hydramycin soluble powder 3000 to 4000 times liquid, or 20% zinc thiazole zinc suspension 600 to 800 times liquid, or 25% copper complex amino acid water agent 400 to 600 times liquid, etc., depending on the incidence of the disease 5 to 10 days spray once.

To control the shell insects, the trunk can be sprayed with stone sulfur compound during the dormant period. It should also be sprayed in early spring, every 14 days in June, while also preventing and controlling other fungal diseases. When the larval activity period is investigated, immediately spray 80% of dichlorvos 1000 to 1500 times liquid or permethrin pesticides, spray once at intervals of 14 days, repeat twice, the effect is remarkable. When the female insect fixes and damages the branch, it can also be used to cut the epidermis of the stem cadre with a knife, and then apply the medicine, so that the plant will suck the medicine inside and kill the insect. Red spiders are harmful to the leaves, and are sprayed with 0.2 to 0.3 baumedo stone sulfur compound and 20% trichloroicide sulfone diluted 500 times liquid. The mixed use of the two liquids is better, and it is sprayed once in 5 to 7 days and used 2 to 3 times continuously.

In the case of weak growth, cloves are occasionally damaged by pests such as cotton aphids, jumping beetles, and wasps, causing sap to flow from the wound. To achieve careful investigation and timely discovery and timely treatment, you can choose 10% imidacloprid wettable powder 2000 times liquid, or 4.5% high efficiency cypermethrin emulsion 1500 times liquid + good wet 3000 times liquid, or 40% chlorpyrifos emulsion 1500 times liquid, or 20% insecticidal urea emulsion 3000 times liquid, 40% oxidized Leguo 800 ~ 1000 times liquid or avermectin spray control. Pay attention to the rotation of chemicals when controlling.

3.2 Field management

3.2.1 Select excellent varieties

Choosing good disease-resistant varieties during planting is also crucial for disease control.

3.2.2 Reduce the source of bacteria

Strengthen management after planting, clean the countryside in autumn and winter, remove the remnants of dead branches and deciduous disease in a timely manner, and reduce the source of pathogen infection.

3.2.3 Prune the branches

Cloves cultivation is not easy to be too dense, need a lot of pruning, if there are several forked trunks, should go to the weak to stay strong, to obliquely stay straight, keep 1. During the growth period, it is necessary to trim and shape in time to control the density of branches and leaves, which is conducive to ventilation and light transmission.

3.2.4 Strengthen drainage and irrigation

Young lilacs have a weak root system, are not drought tolerant, and young trees below 3a need irrigation in the dry season; The flowering and fruiting period is easy to cause flowers and fruits to fall during the dry season, and it is also necessary to irrigate; In the rainy season, attention should be paid to the timely discharge of accumulated water to reduce humidity and prevent water accumulation.

3.2.5 Fertilization

Apply phosphorus and potassium fertilizers in a timely manner, apply less nitrogen fertilizer, apply organic fertilizers such as manure or compost, and mix an appropriate amount of calcium superphosphate and grass and wood ash.

3.2.6 Weeding and soil cultivation

Every year from July to October for weeding and soil cultivation, lilac tree is shallow root system, cover the plant with grass, pay attention not to hurt the roots, prevent the occurrence of nematode disease and root rot, fine roots should not be exposed on the soil surface, if exposed to use fertile loose soil to cultivate soil 2 to 5cm.