The pest of hemp still has corn borer, north Korea black beetle, mole cricket, ground tiger, needle worm, snail, build bridge bug, armyworm to wait.Mole cricket, ground tiger harm seedlings, can kill or heap grass plus toxic bait kill;Snail makes hemp leaf and hemp tip stick together, inhibit growth, can spray lime liquid poison, other pests such as the occurrence of serious pesticide control.

Other diseases of cannabis include: blight of cannabis, dew fungus disease of cannabis (also known as downy mildew), root nematode disease of cannabis, blight of cannabis, blight of cannabis, blight of cannabis, blight of cannabis, blight of cannabis, blight of cannabis, etc. However, the diseases are not common and serious.

Hemp plagiodera

A bronze - green beetle.The worm body length of 1.8-2.6mm, thick russet tip of the wing sheath, leg segments are very developed, good at jumping.The adults of the leaf beetle overwintered at 1 -- 37.5px in the soil or at the leaf, grass, plant residues and soil cracks.The adults nibble cannabis leaves into many holes, affecting the growth of hemp plants, and also nibble inflorescences and immature seeds, causing serious damage to the seedling stage.

Control methods: in addition to the use of chemical pesticides for control, can also be used to eight-leaved roots and locust roots and leaves 0.5kg, add 2.5kg of water to boil for one hour of liquid spray kill;The harm can be mitigated by crop rotation and weed removal.

Small weed weevil

This insect eats hemp only, the adult is harmful to hemp insect, hemp sheath and axillary bud, cause hemp plant to stop growing, from axillary bud send branch, form double head.The adult beetle is a small grayish-brown beetle with a body length of 2.3 -- 2.8mm and a body width of 1.4 -- 1.9mm. It is oval in shape and has a very long muzzle. The abdomen end of the male insect is slightly round.The larvae are milky white and curved like a crescent.The mature larvae are yellowish-white with a body length of 3.3-3.8mm.The chrysalis is milky white, 2.35-2.8mm long, hidden in a circular cocoon of earth.

Control methods: should be mastered in the adult just unearthed before laying eggs before pharmaceutical control.

Marijuana sawyer,

Hemp plant is easy to break in high wind, hemp skin is broken, fiber production, quality reduction.Adults are dark brown, cylindrical beetles, chest and shoulders with two white bands;Overwintering with larvae;They become adults between June and July.Larva burrows into hemp stem to eat, gradually move to the base of hemp stem, insect dung traces at the mouth.

Prevention and cure method: burn hemp root, hemp stem.Drug control in late June.

Brown spot of cannabis

Most occur on the old leaves, the surface of the first leaf appeared, dark brown spots, after the spots expanded into a round or near round, the central part into light brown, around pale yellow, back dense gray mold.This disease mostly occurs in July and forms early leaf litter when the damage is serious.

Prevention and control methods: three elements of nitrogen, phosphorus and potassium fertilizer used together to enhance the disease resistance of hemp plants;Come on when gush bordeaux fluid 2-3 times.

Sclerotinosis of cannabis

It can occur in the whole growth period, and it can happen most quickly under high temperature and wet conditions.Generally, when the seedling height is 750px, the irregular pattern of grey-black disease spots occurs at 250px above the ground, gradually expanding and densely growing black-gray mold, and the seedling will break off and die.When the plant grows to more than 1m, the leaves appear irregular yellowish-white plaques with many black rat droppings of sclerotia.

Prevention and control methods: remove the diseased plant burning grass;Onset of the initial spray of bordeaux fluid 2-3 times.

White star disease of cannabis

The disease occurs in the leaves.At first the surface of diseased leaves has small yellowish-white or yellowish-brown spots along the veins, elliptic or triangular, about 1mm long.After that, the disease spot expands and connects with neighboring disease spot to form large 4 -- 8×3 -- 5mm disease spot.The center of the spot becomes a black or off-white powdery substance, and the surrounding parts are grayish brown or yellowish brown.The early deciduous leaves and stunted growth will affect the yield.

Prevention and treatment: remove the diseased leaves and burn them;Pay attention to drainage;Onset of the initial spray of bordeaux fluid 2-3 times.