Soil Borne Diseases, mainly plant pathogens living in the soil with crop residue. Apply inappropriate farming, irrigation, fertilization, planting methods, and other agronomic measures. And climatic factors, mainly including temperature, humidity, light, and so on. It causes the pathogen to multiply rapidly. The pathogens spread to infect the crop root or the stem.
The reason for the aggravation of soil-borne diseases is the formation of the dominant population of pathogenic bacteria in soil and the reduction of beneficial microorganisms.
The infectious pathogens mainly include fungi, bacteria, actinomyces, viruses, nematodes, etc.
The fungus is the leading cause of soil-borne diseases. Such as rot mold caused seedling rot and quenching disease, root rot disease, sheath blight; Rhizoctonia caused seedling blight; Fusarium spore, yellow wilting spore, and other causes crop blight, bacterial wilt, blight, etc.
Causes of Soil Borne Diseases
1. Continuous Cropping
Due to the long time’s continuous cropping, the root exudates of continuous cropping and some pathogenic microorganisms accumulate in the soil.
Soil microbial ecological community destroyed, the farmland ecosystem becomes fragile, harmful microorganisms increase, beneficial bacteria decrease.
The poisonous matters & pathogenic bacteria increase in soil, the inhibition of soil to bacteria decreases, the biological property deteriorates, the natural fertility decreases, and the soil-borne diseases increase.
2. Incorrect Field Application
Incorrect field operations such as Improper cultivation, flood irrigation, excessive application of chemical fertilizer, etc. Soil hardening & nutrient imbalance cause the crops to grow badly; the resilience of plants decreases. Soil-borne diseases are becoming more and more serious.
3. Global Climate Warming
The greenhouse effect causes the climate to show a warming trend. Extreme weather is becoming more common, creating a crisis in agricultural security.
Warm winter provides favorable conditions for the pathogens to survive from winter to spring. It brings some hidden troubles for the occurrence of disease in the coming year.
Prevention of Soil Borne Diseases
There are two conditions for the occurrence of soil-borne diseases.
1. Number of pathogens;
2. Climatic influences
The biggest climatic influences are temperature and humidity. When the conditions are suitable, the pathogen will infect the root and stem of the crop and cause the disease of the plant.
Controlling the occurrence of soil-borne diseases should focus on eliminating pathogenic bacteria, reducing the source of bacteria and inhibiting the onset conditions.
Adopt the principle of “prevention first, treatment second, prevention and treatment combined, comprehensive strategy.”
1. Deep Ploughing
The most active site of soil pathogens was about 5 cm under the surface of the soil. It’s also the most widely distributed area of the crop root system, susceptible to infection by pathogens.
If plowing deep, turn the topsoil below 20cm. It will significantly reduce the number of pathogens. Reduce the occurrence of soil borne diseases.
2. Apply Biological Products
We divided soil microorganisms into two categories, one is pathogenic bacteria that harm crops and cause disease.
And the other is beneficial bacteria. Promote the root of crop robust growth, improve the activation of soil, nitrogen fixation, phosphorus, potassium.
The two kinds of soil microorganisms have antagonistic action and mutual inhibition.
Applying biological fertilizer is to supplement the beneficial bacteria in the soil and expand the beneficial bacteria group. Inhibit and kill harmful bacteria to reduce soil borne diseases.
The most common biofertilizer is Bacillus subtilis, Bacillus licheniformis, Bacillus laterosporus, Trichoderma harzianum etc.
3. Soil Disinfection
By applying fungicides to the soil, remove all microorganisms in the soil that may cause plant infection, poisoning, or adverse effects. Sometimes use the steam for soil disinfection to improve the control effect.
4. Select Disease-Resistant Seeds
One of the most economical and effective methods for production is to select disease-resistant varieties seeds suitable for local climatic conditions and soil conditions and rely on healthy disease-resistant genes.
5. Seed Treatment
By seed treatment technology, wrap fungicides, insecticides, micro fertilizers, plant growth regulators, and colorants around the seeds. To improve resistance, disease resistance, accelerate germination, promote seedlings, increase production.
6. Crop Rotation
Crop rotation is an effective method of planting different crops or combinations of multiple vegetables in the same field in a sequential manner. The reason is that many pathogens have a single host. It’s one of the effective ways to prevent soil-borne diseases.
Crop rotation is beneficial to the control of pests and weeds. At the same time, it is advantageous to the balanced utilization of soil nutrients, the improvement of soil physical and chemical properties, and the regulation of soil fertility.
Control of soil-borne diseases does not only depend on chemical management. Integrated disease management practices will be more suitable for modern agriculture, and can better control the spread of harmful pathogens in the soil.