Crop dead tree disease is caused by Phytophthora and Fusarium solani from the base of the stem. A few days later, the whole plant withers from top to bottom.
What is a dead tree germ
Several diseases of dead trees caused by Phytophthora and Fusarium solani, such as pepper blight, eggplant blight, and tomato Phytophthora root rot are all caused by Phytophthora infection; pepper rot skin Fusarium root rot, eggplant rot Bark root rot and cucumber root rot are caused by Fusarium solani infection.
Classification of diseases that caused dead trees
1. Diseases of dead trees caused by Phytophthora.
Pepper blight, eggplant blight, and tomato Phytophthora root rot have the common point of the stem base. In addition to the stem base, the root rot also occurs. The above three diseases are all manifested as sunny days. The leaves wilt during the day and will recover sooner or later, and the whole plant will wither and die after repeated several days.
2. Diseases of dead trees caused by Fusarium solani
The root rot of pepper rot, Fusarium rot on eggplant, and Fusarium rot on cucumber is root disease. In addition to root rot on cucumber, Fusarium root rot on cucumber is on the stem base. The lower part of the disease is also affected. The above three diseases are also manifested as leaf wilting during the day, which can recover sooner or later, and the whole plant will wither and die after a few days.
There are five main types of dead tree disease prevention and control:
(1) Choose disease-resistant varieties;
(2) Seed disinfection;
(3) Ridging and planting are conducive to watering and fertilization, which can significantly reduce the harm of soil-borne diseases, and at the same time enhance the air permeability of the soil, which is conducive to rooting.
(4) Strengthen the management of the shed, control watering, especially in continuous cloudy weather, avoid flooding with flooding, pay attention to the ventilation and dehumidification, and prevent excessive humidity in the shed.
(5) Chemical control.
Research has found that the factors that cause dead seedlings and dead trees can be divided into the following aspects:
（1）Serious soil salinization or acidification
In the process of vegetable production, the blind pursuit of yield and excessive fertilization caused more than one-third of the fertilizers to be absorbed by plants.
When the degree of salinization is high, the capillary roots grow poorly or die quickly, the roots have difficulty in absorbing water, and even backflow, leaf wilting, yellowing, and poor fruit coloration will occur.
（2）Mass accumulation of self-toxic substances
Planting vegetables year after year is bound to cause the accumulation of self-toxic substances. For example, the root rot of cucumber seedlings can be caused by the decay of cucumber residues, and the extract of soybean decay has a significant inhibitory effect on the germination of soybean seeds and the growth of radicle.
（3）Increased pathogenic bacteria in soil
The selective enrichment of microorganisms means that the number of bacteria and actinomycetes in the soil has dropped overall, the number of fungi has risen significantly, and the number of pathogenic bacteria has increased sharply. It causes soft rot and blight of vegetables, bacterial wilt and damping-off of Solanaceae, and vine blight of melons.
（4）Severe root diseases
For a long time, most vegetable farmers only pay attention to the management of the above-ground part, that is, control only when the leaves and fruits are diseased, and the awareness of the prevention and control of underground diseases is weak.
Soil-borne diseases such as melon wilt, tomato bacterial wilt, root-knot nematode disease, root cancer, etc., spread widely, and once they are infected, it is difficult to control. There are more fat burning roots, water big retting roots and so on.
In summary, the main cause of dead vegetable seedlings lies in the soil.