The latest technical methods of pest control of chrysanthemum

Chrysanthemum chrysanthemum is a semi-cold-tolerant vegetable, which is not strict with light. It is native to the Mediterranean. It has been cultivated in China for more than 900 years and is widely distributed, but the cultivation area in the north and south is very small. In the process of cultivation, we should pay attention to the prevention and control of diseases and insect pests. Let's take a look at the pest control techniques of Artemisia annua.

Blight disease

[symptoms] mostly occur in the middle and later stages of seedling breeding. It mainly harms the stem base or underground root of the seedlings, which is oval or irregular dark brown disease spot at first, wilts in the early day, recovers at night, the disease part gradually sinks and overflows, and some gradually changes to dark brown, when the disease spot expands around the stem for a week. Finally withered and died, but did not lodge. The mildly diseased plants only saw brown sunken disease spots and did not die. When the seedbed humidity is high, the light brown arachnoid mold can be seen in the disease department.

[prevention and treatment] at the initial stage of the disease, 38% cuproloxil 800x solution, or 41% poly (pyrimidine) 600x solution, or 20% methyl ibuprofen EC 1200 times, or 72.2% Prik water agent 800x solution, was sprayed once every 7 days. Or the general + door god diluted by 600 times the liquid, 3 liters per square meter before sowing or after sowing and before planting. At the time of planting or after planting and before the expected disease occurrence period, the product was diluted with 600 times solution and irrigated with roots, and the drug was used once every 7 days, depending on the disease.

Leaf spot disease

[symptoms] Celosia cristata leaf spot infects leaves, petioles and stems. The disease spot is round on the leaf, then enlarges into irregular large disease spot, and produces wheel pattern. The disease spot changes from reddish brown to dark brown in the center, brown and long on stem and petiole. There are small black-brown round spots on the leaves of fish-tail sunflower leaf spot, and then enlarged or the disease spots show irregular large patches, the edge is slightly raised, and there are small black spots on both sides of the leaves. Cymbidium leaf spot (there are oval, long, light reddish brown disease spots on the leaves, there are green circles around, and then expand into large irregular patches, and black spots are produced on the disease spots.

[prevention and treatment] at the initial stage of the disease, 4% pyrimidine nucleoside antibiotics 20 ml + 41% polypyrimidine 20 ml, mixed with water 15 kg of water, 5-7 days once, 2-3 times.

Sclerotinia disease

[symptoms] are mainly harmful to stems, leaves and fruits. The base of the stem was infected with primary watery spots, and then expanded into light brown, resulting in soft rot or longitudinal crack of the stem base, and white cotton-like mycelium appeared on the surface of the diseased part. When the leaf is infected, there are gray to grayish brown wet rot spots on the leaf surface, and the boundary between the disease spot edge and the healthy part is not obvious. when the humidity is high, flocculent white mold appears on the spot surface, which eventually leads to leaf rot. The fruit was infected with water-soaked spots at first and wet rot after enlargement, showing dense white cotton-like mycelium, and black mouse fecal sclerotia appeared on the surface of the disease in the later stage of the disease.

[prevention and treatment] in the middle and early stages of the disease, the prevention and treatment of 20% silazomide 30 ml + carbendazim 25 ml, mixed with water 15 kg of water, 5-7 days once, 2-3 times.

Vegetable borer

[symptoms] the early instar larvae eat the heart leaves of the seedlings, spitting silk and forming a net, which will affect the growth of the seedlings, and the severe ones can cause the seedlings to die, resulting in lack of seedlings and ridge. in addition to eating the heart leaves, the older larvae can also eat the stem pith and roots, and can spread bacterial soft rot, causing vegetable plants to rot and die.

[control] during the peak incubation period of the larvae or when the heart leaves were killed and the screen was first seen, 5% Yitaibao EC was sprayed 2-3 times, and pay attention to spraying the medicine on the heart of Chinese cabbage.

Aphids

[symptoms] aphids are pests of piercing and sucking mouthparts, often clustered in leaves, tender stems, flower buds, terminal buds, etc., pricking and sucking juice, causing leaves to shrink, curl and deform, and in serious cases cause branches and leaves to wither or even the whole plant to die.

[control] when the number of 100 aphids in the field reached 500 and the benefit-to-damage ratio was more than 1 ∶ 500, 50 ml of 25% aphid acarine EC per mu, or 1500-2000 times of imidacloprid series products, 60-70 grams of 10% aphids, 2500 times of 20% imidacloprid, and 25% 3000 times of aldicarb were sprayed. The wheat aphid resistant to imidacloprid and acetamiprid should not be used alone, but could be sprayed reasonably with low toxic organophosphorus pesticides.