Evening primrose pests and diseases and their control methods

Diseases and prevention methods of evening primrose

Rot

Rot is one of the diseases that plague evening primrose. After becoming infected, the roots of the plant gradually change color and rot, the leaves shrink and dry up, and in severe cases, the entire plant may die.

Prevention and treatment methods

You can use 1% lime water, or 1500 times diluted 50% thiophanate-methyl, or 1000 times diluted 75% chlorothalonil for irrigation.

Leaf spot

Leaf spot disease mainly harms the leaves of evening primrose. The pathogen is Septoria oenothera, which belongs to the subphylum Ascomycota and the genus Septoria. The pathogen overwinters in diseased remains in the form of conidiophores and mycelium. In the spring of the following year, the conidiophores absorb water and release conidia for initial infection.

The transmission of leaf spot disease mainly relies on raindrop splashing and air circulation. Seeds carry the bacteria, causing long-distance transmission. The disease is most likely to occur in a high temperature and high humidity environment, so the hot and rainy season from July to August every year is the peak period of the disease.

After becoming infected, round, light brown spots will appear on the leaves, about 2-3 mm in diameter, with purple-red edges, brown in the middle, and densely covered with small black spots. In severe cases, the leaves will gradually dry up and fall off.

Prevention and treatment methods

In autumn, completely remove diseased leaves and seriously diseased plants, burn them and discard them in a centralized location.

Before sowing, soak the seeds in 500 times diluted 50% carbendazim or 50% mancozeb for 30 minutes, and then plant them after drying.

In the early stage of the disease, spray 500 times diluted 50% mancozeb or 600 times diluted 50% mefenamic acid once, with an interval of 10-15 days.

Evening primrose pests and control methods

Aglaonema cooperi

This pest will harm plant seedlings in the larval stage, chewing branches and stems, causing poor development of seedlings.

In the adult stage, it will affect the flowering of the plant and have a certain impact on the petals.

Prevention and treatment methods

Use roasted wheat bran and 30 times diluted 90% crystalline dichlorvos to make poison bait to kill insects.

Mix the bait directly with 50% phoxim emulsifiable concentrate in a ratio of 1:1 to kill the insects.