How to Treat Poplar Diseases? A Detailed Guide to Prevention and Control Methods
Poplar is a deciduous tree of the genus Populus in the family Salicaceae. Its trunk is tall and majestic, neat and uniform, and it can prevent wind and sand and absorb exhaust gases, so it is widely used in ecological shelterbelts, the Three-North Shelterbelt, agricultural and forestry shelterbelts, and industrial timber forests. So, how to treat poplar diseases?
1. How to treat poplar diseases?
This depends on what disease has occurred in the poplar before the corresponding prevention and control method can be adopted. Its diseases include rust, seedling chlorosis, black spot, rot, leaf blight, canker, and so on. Different diseases require different prevention and control methods.
2. Introduction to poplar diseases
1. Rust
Damage: It mainly affects leaves, and also affects petioles, young shoots and winter buds. It is most severe in May and June, when leaf lesions join together into patches and often cause scorched leaves and leaf drop. The disease is milder during the rainy season, and a second peak period occurs from August to September.
Prevention and control: Spray with 25% triadimefon wettable powder at 1000-15000 times dilution, 65% zineb at 500 times dilution, or disodium 200 times dilution; when the disease occurs, spray 1:1:125-170 Bordeaux mixture once, then use 0.3-0.5 degrees Baume lime sulfur mixture for control.
2. Seedling chlorosis
Symptoms: It mostly occurs in slightly alkaline plots and is generally nitrogen deficiency or iron deficiency.
Prevention and control: Spray with 0.3% ferrous sulfate (black alum) plus 0.5% urea solution, Lüheng Iron King, or Tiedaling at 2000-3000 times dilution, once every 7-10 days, 2-3 times is enough.
3. Black spot
Damage: It generally spreads and causes disease from May to July via rainwater, with the peak period from July to August. Under conditions of high temperature and heavy rain, continuous cropping land, poor seedling growth, low-lying land, and excessive seedling density with high humidity, the disease is severe; when severe, the entire leaf turns black and dies.
Prevention and control: Spray 1:1:125-170 Bordeaux mixture once every 10-15 days, or spray 65% wettable zineb, ferbam at 250 times dilution, or 25% carbendazim at 200 times dilution. During the rainy season, add 0.3% glue (or soybean powder, soybean juice, etc.) to the spray to increase adhesion and prevent wash-off.
4. Rot
Damage: It mainly harms various parts of poplar trunks and branches. The lesions are irregular in shape and vary in size. The lesions of this disease expand outward every year, and when they encircle the branch or trunk, all the upper branches and trunk will die. In years with heavy spring and summer rainfall, rot occurs severely.
Prevention and control: Scrape off the lesions with a knife, scraping down to healthy tissue, then apply 10 times edible alkaline water or 20% agricultural antibiotic 120 aqueous solution at 10 times dilution to the lesions, applying 2 to 3 times in a row is enough.
5. Leaf blight
Damage: It harms poplar leaves, young shoots and young stems, and affected leaves are most severely infected from May to June. Nearly round, polygonal or irregular lesions appear on affected leaves, 1 to 5 mm in diameter, and when there are many lesions they can join into large patches.
Prevention and control: At the beginning of the disease, carry out chemical control, spraying 2 to 3 times during the entire growing season, using 40% phosethyl-Al at 300 times dilution, or 75% chlorothalonil at 500 times dilution, or 50% carbendazim at 1000 times dilution for control.
6. Canker
Damage: It mainly harms the middle and lower parts of the trunk. It begins to occur in April, and the first disease peak forms from late May to June. From July to August, when the temperature rises, the disease slows down, a second disease peak appears in September, and it stops after October.
Prevention and control: Before the disease peak, apply 70% thiophanate-methyl at 100 times dilution to the trunk.