Common diseases and pests of poppy and their control methods

Bacterial spot of poppy

Symptoms

Leaves, stems, flowers and other parts are all damaged by bacteria. Initially, tiny water-like spots appear on the leaves, which soon turn into round dark brown spots, often with concentric rings and water-like halos around them. However, the halos on old diseased spots are not obvious.

When the disease is severe, the spots on the leaves will merge to form large black to jet-black patches, and pus will overflow. The spots on the flower stems are long and strip-shaped, gradually converging and cutting the flower stems in half!

Flowers, especially young calyxes, are most susceptible to infection and may turn partially or completely black. The most terrifying thing is that the bacteria can pass through the sepals and infect the tender petals below, causing the flowers to stop developing and die when they are young. This will manifest itself on the capsule as obvious water-soaked black spots, and the bacterial pus will be more obvious than in other parts.

Disease pattern

It occurs throughout the entire growth and development period of the poppy, and is most common under humid conditions, causing serious damage to the poppy.

Moreover, the pathogen can infect other poppy plants, and even seeds and soil can carry this bacteria!

Prevention and treatment methods

(1) Remove diseased leaves, pull out diseased plants and burn them; do not bury them.

(2) Collect seeds from disease-free plants, and soak suspicious seeds in warm water before sowing.

First soak the seeds in cold water for 7 hours, then soak them in 49℃ warm water for 5 minutes, then put them in 54℃ warm water for 5 minutes, and finally cool them in water.

(3) Do not allow the field or flowerpot where poppies are planted to be hot and humid or poorly ventilated, and be careful not to apply too much fertilizer.

Downy Mildew

Symptoms

If the disease occurs during the growth period of poppy seedlings, it will cause the seedlings to wither. If the disease occurs in adult poppies, it will harm the leaves, flower stems and inflorescences. Light brown spots appear on the front of the old leaves on the underside of the plant, and a white, light gray or purple-gray downy mildew layer appears on the back of the leaves. In severe cases, the leaves turn brown and dry, and the pathogen spreads to the stems and flowers, causing the stems to twist and the flowers to stop blooming. If the disease occurs at the base of the stem, the plant will die.

Disease pattern

The pathogen overwinters and oversummers as oospores. The infection is spread by conidia.

Overly dense planting, poor ventilation, excessive humidity and excessive nitrogen fertilizer can easily lead to disease.

Prevention and treatment methods

(1) The land should be leveled to prevent waterlogging. Planting should not be too dense. Appropriate nitrogen fertilizer should be applied. Diseased leaves should be cut off in time, and diseased plants should be removed and burned.

(2) Several disinfectants that can be sprayed at the early stage of the disease.

600 times diluted 50% mancozeb, or 4000 times diluted 20% ritoxin, or 1000 times diluted 50% mancozeb.

Corn poppy rot

Symptoms and causes

If too much nitrogen fertilizer is applied, the plants are too dense or the crops are cropped continuously for many years, rot will occur.

Prevention and treatment methods

Diseased plants need to be removed promptly. Just sprinkle some lime powder on the original place.

Corn Poppy Pests

Symptoms and causes

Poppy rarely suffers from diseases and insect pests, but it is sometimes harmed by beetle larvae and scale insects.

Prevention and treatment methods

If insect infestation is found, the following insecticides can be used for treatment.

Spray 1000 times diluted 40% oxydemeton-methyl, twice every 7 days.