Diseases and their control of Paulownia

Paulownia witches' broom

That is broom disease, which has a great impact on the growth of seedlings and young trees, causing slow growth of the plants and even death in severe cases. When young trees become infected, small branches and leaves often grow in clusters on the main trunk or branches, making them look like brooms or bird nests. The prevention and treatment methods are as follows:

1. Select the roots of disease-free mother trees as propagation materials. Seedlings grown from seeds are less susceptible to witches' broom;

2. When branches first become diseased, they should be pruned off as soon as possible. Do not damage the roots, bark and branches during the growing season.

3. Soak the diseased root cuttings in warm water at about 50°C for about 10 minutes. Burying the residue of lime sulfur in the soil at the roots of diseased plants and spraying the diseased plants with 0.3 degrees lime sulfur can effectively inhibit the development of the disease.

Paulownia Anthracnose

Anthracnose mainly harms the leaves, petioles and tender stems of Paulownia seedlings, especially in May-July when it rains a lot or when the seedlings are thin and too dense. The prevention and treatment methods are as follows:

1. The density of sowing seedlings should be appropriate. After the seedlings emerge, it is necessary to promptly thin out, fertilize, till the soil, drain the water, cultivate strong seedlings, and improve their disease resistance; 2. Deal with nurseries with diseases. Before sowing, spread ferrous sulfate evenly on the surface and then turn it into the soil;

3. After the seedlings emerge, you can spray Bordeaux mixture or 50% thiophanate-methyl diluted 800-1000 times, once every 10 days.

Paulownia black pox

It mainly harms the leaves, petioles, stems and tender shoots of young Paulownia trees, causing dieback. Symptoms include oval lesions on petioles and young stems, which are raised like scabs and are dark brown to black in color. The prevention and treatment methods are as follows:

1. In winter, diseased seedlings and branches and leaves should be thoroughly removed and burned, and deep plowing should be carried out to reduce the source of the disease. In the early stage of the disease, the diseased plants should be removed in time to prevent the disease from spreading;

2. After the seedlings emerge from the soil, you can spray 1:1:150-200 Bordeaux mixture or 500 times 65% wettable mancozeb solution, once every 15 days or so, and 3-4 times are needed.

Paulownia rot

The susceptible parts are mainly the trunk, main branches, side branches and branch forks, especially the main and side branches, while the small branches are rarely affected. The prevention and treatment methods are as follows:

1. When transplanting, avoid damaging the roots too much or the trunk, and water the tree promptly after planting.

2. Prune scientifically, prune frequently, gently, timely and reasonably. The cut ends should be smooth, and diseased and dead branches should be removed in time.

3. Severely diseased Paulownia should be removed promptly. For plants that are less susceptible to the disease, management should be strengthened, the diseased parts should be scraped off in time, and then spraying or applying medicine should be carried out. 1% thiophanate-methyl, 5% thiophanate-methyl, etc. can be used for prevention and control.