Common diseases and pests of cosmos and their control

Common diseases of cosmos and their prevention and treatment

The common diseases of cosmos are brown spot disease, powdery mildew and grass stem blight. Among them, grass stem blight is the most common, which mainly harms the stems and leaves of cosmos. Its symptoms are: in the early stage of the disease, rash-like protrusions appear on the plant stems, which are gray in color, fusiform or round in shape, and in the later stage, the rash-like protrusions will crack. Grass stem blight also occurs frequently during the growing season of cosmos, and in severe cases can cause the plant to die.

Prevention and control methods: ① Carry out drainage work in time after rain to prevent moisture retention. ② When spraying medicine in the early stage of the disease, you can choose a specific solution of benomyl-cyclohexine emulsifiable concentrate, thiophanate-methyl suspension and green depo suspension. The spraying cycle is seven days, and spray 2 to 3 times.

Common pests of cosmos and their control

The common insect pest of cosmos is mainly red spider mites. Red spider mites will suck the juice from the stems and leaves, which reduces the moisture in the affected parts. The leaf surface will appear densely packed with pale spots, and the leaves will curl and turn yellow. In severe cases, the plant may develop yellow leaves. Leaves may curl, burn, fall or even die. Red spider mites are also a vector of viral diseases.

Prevention and control methods: Strengthen cultivation management. In the early stage of insect pests, you can use 20% trichlorodicofol emulsifiable concentrate at 500~600 times for prevention and control.

Mauve has certain medicinal value. It is mainly used to clear away heat and detoxify, relieve cough and reduce phlegm, treat wind-heat colds, dysentery, costitis, stomatitis and other diseases.

The medicinal value of cosmos is so high, flower lovers should take good care of cosmos and try not to let it be invaded by diseases and pests!