How to prevent and cure root rot?

Root rot is due to root rot, the function of absorbing water and nutrients gradually weakens, and finally the whole plant dies, which is mainly manifested as the yellowing and withering of the leaves of the whole plant, which usually occurs from late March to early April and enters the peak period in May. it can be caused by Pythium, Fusarium, Phytophthora and other pathogens. Let's take a look at how to prevent and cure the root rot.

Symptoms of root rot

Root rot mainly harms seedlings and can also occur at the adult stage. At the initial stage of the disease, only individual branch roots and fibrous roots are susceptible, and gradually expand to the main root. After the main root is susceptible, the plant shows no symptoms in the early stage, and later, with the aggravation of the root rot, the function of absorbing water and nutrients is gradually weakened. the aboveground part is in short supply of nutrients, the new leaves first turn yellow, when the light is strong and the evaporation is large around noon. The upper leaves of the plant wilted, but recovered at night. When the disease was serious, the wilting condition could not recover at night, and the leaves of the whole plant turned yellow and withered. At this time, the root bark turned brown and separated from the pith, and finally the whole plant died.

Pathogenic mechanism of root rot

Root rot is often similar to retting root symptoms and is a fungal disease. The pathogen usually winters in the soil and on the residual body, usually from late March to early April, and enters the peak period in May, and its occurrence has a great relationship with the climatic conditions. the seedling bed is low temperature, high humidity and lack of light are the main environmental conditions to cause the disease. the seedling soil is sticky, easy to harden and poor ventilation, which leads to the hindrance of root growth and development. In addition, after the roots are harmed by underground pests and nematodes, there are many wounds, which is beneficial to the invasion of bacteria. In this environment, not only the herbaceous flowers of sowing and cutting are vulnerable, but also the woody flowers such as rose, hibiscus and mulberry are also easy to occur.

Organic control of root rot

1. Agricultural prevention and control: strengthen the management of the seedbed, the soil cover should not be too thick after sowing, the watering of the seedbed should depend on the soil moisture and weather, and the amount of water should not be too much. Do not water around noon in summer, ploughing more, to provide soil permeability.

2. Physical control: soak the seeds in 55 ℃ warm water for 10 minutes.

3. Chemical control: prevent the use of wettable powder in the seedbed to irrigate the root according to 2g per square meter, or 1500 to 3000 times before or at the initial stage of the disease, 200ml per plant. When the disease is serious, the diseased plants should be removed and root irrigation should be carried out at the same time.

How to prevent and cure root rot?

1. Selected varieties: select and integrate the seedling plots. High quality varieties were selected, and the seeds were soaked and treated with seed coating agent, and the seeds were sowed at the right time.

2. Disinfection treatment: before sowing, the seeds can be treated with 0.3% of seed weight or 0.1% of seed weight or soaked in 2000 times of 80% antibacterial agent EC for 5 hours, and the base of cuttings can also be soaked in the same concentration solution for 1 hour before cutting.

3. Soil disinfection, the seedbed can use carbendazim and carbendazim for soil disinfection and can also treat catchment disease and blight disease.

4. Cultivate strong seedlings: cultivate the land carefully, cultivate strong seedlings carefully, try not to hurt the roots during transplanting, arrange them carefully, ensure that there is no stagnant water retting roots, and apply sufficient basic fertilizer.

5. Appropriate watering: after planting, according to the change of air temperature, timely and appropriate watering should be done to prevent water evaporation and transpiration of seedlings, and isolate virus infection.

6. Spraying phosphate fertilizer: spraying phosphate fertilizer at flower bud stage, young fruit stage and fruit expansion stage to enhance plant nutrition matching function, thicken fruit pedicel, promote plant healthy growth and enhance disease resistance.

7. Chemical control: copper preparation or metachlorin can be used to control the disease, and metachlorin or copper preparation can be used to irrigate the root. At the same time, the harm of underground pests and nematodes can be controlled in time.