What are the specific symptoms of apple tree silver leaf disease? Under what circumstances is it easy to do?

Everyone has eaten apples. But when growing apples, apples are easily affected by a disease. That's silver leaf disease. So what are the symptoms of apple silver leaf disease? Under what circumstances are apple trees prone to silver leaf disease? Let's take a look at it with the editor.

First, what is the situation that apple trees are prone to silver leaf disease?

Answer: spring and Autumn season

Spring

1. Apple trees in spring are rich in carbohydrates and are most susceptible to disease. After pruning, we should pay attention to protect the wound, do not let the xylem exposed, otherwise, encounter spores under rain, is the most likely to induce the disease.

2. In orchards that are prone to drought in early spring, after months of wind and sun washing, large wounds after pruning will appear on the surface. There are more kinds of saprophytic bacteria, which will interfere with the infection of silver leaf pathogens. Therefore, there is no silver leaf disease in these orchards in early spring arid areas.

3. From April to May, in the environmental conditions where there is more precipitation and the air is relatively humid, such as the old route of the Yellow River and the Yangtze-Huaihe River Basin, the pathogen can take the opportunity to invade the tree condition which is suitable for silver leaf pathogen infection without protective treatment.

Spring and Autumn period

In the spring and autumn season, catching up with Rain Water's frequent outdoor environment with high humidity is the main condition under which the disease can prevail. When the temperature rises to about 13 ℃, if it catches up with another 2 days of continuous rainfall, a new primary infection source fruiting body will appear. In the apple orchards in Jiangsu and Henan provinces, the fruiting bodies first appeared from early April to late June, and the occurrence time was slightly different according to the rainfall. The basidiospore emitted by the fruiting body finally falls on the wound of the apple tree with the help of the airflow. Taking advantage of the wet environment, the spores quickly invade the apple branch and spread up and down the transport system. The pathogen invaded for about 90 days, and the apple tree began to get sick. The newly formed secondary fruiting body is from September to November, which can lead to another infection.

2. Symptoms of apple silver leaf disease

Summer disease attack

1. If one day you find that the leaves of an apple tree have become gray or silver-white, then your apple tree is already suffering from silver leaf disease.

2. The symptom of silver leaf disease was found to be gray in the early stage. At a later stage, it was found that the color was silvery white. When the temperature rises and the weather is hot, the diseased leaves will also show brown spots.

3. The morphological change is smaller than that of normal leaves, and there is no toughness, brittleness and lighter color, like chlorophyll.

4. The dried branches of apple trees corroded by silver leaf disease become light brown. With the development of the disease, the color of the diseased place deepens little by little, and its tissue becomes drier and drier. It smells a little fishy. If you rub it slowly, the epidermis of the leaves can be easily separated.

Autumn disease onset

The main results are as follows: 1. After the beginning of autumn, the symptoms of silver leaf disease become more and more obvious, the epidermis of diseased branches and leaves are partially cracked, and the exposed mesophyll spots are brown after cracking. Most of the shapes are long and irregular. In the end, the mesophyll spot will be ruptured and perforated.

2. At first, the disease only appeared on one or two branches, and then spread to other branches. After dissecting the newly infected branches, the xylem at the base has turned into brown stripes, developing seriously diseased branches and rotting roots, which ends about two years later.

3. Under rainy and continuous cloudy conditions, the wood branches decayed by disease will grow into something similar to fungus, with purple-brown color, overlapping layers, good-looking, gray after drying, and horizontal stripes on the back.

All right, that's all for the symptoms of apple silver leaf disease today. Friends who like it are welcome to forward, comment and share. For more information, you are welcome to follow Tuliu.com. I'll see you next time. Bye.