Prevention and control methods of major diseases and pests of mint

Mint rust

Harmful to mint leaves and stems.

Excessively wet or dry weather in May and June can easily cause this disease. Specifically, in the early stage, orange-yellow powdery summer spore piles appear on the back of the leaves, and in the later stage, black-brown powdery winter spore piles appear. Failure to promptly treat the disease will lead to withering and falling of leaves, and eventually death of the entire plant.

When the virus first infects, spray 1000-1500 times of 20% triadimefon emulsifiable concentrate or 300 times of sodium dimethoate.

Leaf spot

Also known as "white star disease," it is harmful to mint leaves.

The peak period is from May to October. Specifically, small dark green circular spots appear on the leaves, which gradually expand into dark brown spots with grayish-white star shapes in the middle and small black dots dotted on them. The leaves will slowly wither and fall off.

If diseased leaves are found, they should be removed and burned. Spray 70% mancozeb and 75%

500-700 times dilution of Thiophanate-methyl. Do not spray after 20 days before harvest.

Cutworm

This pest can cause harm to young seedlings. In spring, the stems of the seedlings will be eaten by their larvae, resulting in a shortage of seedlings.

The roots should be sprayed with 2000-3000 times diluted 40% chrysanthemum emulsion and 40% methyl isothioate emulsion, or irrigated with 1000 times diluted 40% methyl isothioate.

Spodoptera exigua

This pest will harm the flower buds and leaves, and the leaves will be eaten by its larvae, leaving holes.

Add water and spray 50% concentration of Yitaibao emulsion (30-60 ml per mu) or 1000 times concentration of 50% concentration of cypermethrin. Also, do not spray pesticides 20 days before harvest.