CN104623705A - Quick sterilization method of banana wilt soil-borne pathogenic bacteria - Google Patents

Abstract

The invention provides a rapid sterilization method for soil-borne pathogenic bacteria of banana fusarium wilt (Fusarium oxysporum cuba-specialized type), which belongs to the technical field of agricultural land management and agricultural utilization. First, add organic carbon source to the continuous cropping soil with continuous cropping obstacles or high incidence of banana wilt and maintain the soil anaerobic state to create a strong reducing environment. Within 72 hours, the redox potential of the soil will be reduced to below -80mV, and then maintained The soil was in a strong reducing environment for 2 to 4 weeks, and a healthy soil with a low content of Fusarium oxysporum Cuban specialization was obtained. The strong reducing environment created by the invention can quickly promote the growth and metabolism of anaerobic microorganisms in the soil, produce a large number of metabolites, effectively reduce the number of Fusarium oxysporum in diseased soil, not only improve the soil microbial flora, but also reduce crop soil-borne diseases occurrence; the invention can increase the pH value of the acidified soil and improve the physical and chemical properties of the soil; the invention has low cost, readily available materials, simple operation and easy popularization at the grassroots level.

Description

A kind of rapid sterilization method of soil-borne pathogenic bacteria of banana fusarium wilt

technical field

The invention belongs to the technical field of agricultural land management and agricultural utilization, and relates to a biological disinfection method for quickly reducing the number of pathogenic microorganisms in banana continuous cropping soil, and in particular to a rapid sterilization method for soil-borne pathogenic bacteria of banana wilt.

Background technique

Bananas are one of the most important crops in the world, serving as a major food and economic source in many developing countries. Bananas are a stable export commodity in the agriculturally based economies of Latin America, Africa and Asia, and are the fifth most important agricultural commodity in world trade. At the same time, banana is one of the five famous and high-quality fruits in southern my country, and is an important resource for domestic market and export earnings. Bananas are grown in 120 countries and regions around the world. With the increasing demand for bananas, the banana industry will play a more important role in the future national economy. While the global banana industry is developing rapidly, a disease that is destructive to bananas—soil-borne banana wilt is also spreading in banana planting areas. Some banana gardens can no longer grow bananas, and there is a phenomenon of abandonment. As a result, the banana planting area has gradually decreased, and the banana industry has been hit hard.

Soil-borne banana wilt, also known as banana Panama disease and yellow leaf disease, is a devastating fungus that causes vascular necrosis caused by Fusarium oxysporum f.sp.cubense in the soil disease. In 1874, the disease was first discovered in Australia. In the 1950s, it broke out in Panama and other countries in Central and South America, which made Damishe, the world's largest internationally traded banana variety, extinct. At the end of the 1960s, Taiwan, China Soil-borne banana wilt occurred in Taiwan Province, and then locally occurred in the Philippines, Australia, Malaysia, Africa and other countries and regions; after the 1970s, soil-borne banana wilt became prevalent in Taiwan Province, causing the banana area to grow from 50,000 hm at the peak ² has dropped to 5,000 hm ² in recent years, and half of them are still affected; in mainland China, in the 1950s, fusarium wilt of banana was found in Guangzhou, but no banana was found to be infected with the disease; until 1996, it was not found in Wanqing, Panyu City, Guangdong Province Soil-borne banana wilt was found in the sand. Because it was not controlled in time, the disease spread rapidly through seedlings and other ways, which has caused many banana orchards to abandon their land and plant other crops. Subsequently, it was discovered successively in Guangxi, Fujian, Hainan, Yunnan and other regions, which brought heavy losses to banana production. The disease has become the number one disease in the main banana producing areas of my country.

Fusarium oxysporum, the causative agent of Fusarium wilt, belongs to the genus Deuteromycetes, from the order Stems, the family Tumoraceae, and the genus Fusarium. Currently, the Cuban-specific type of Fusarium oxysporum is subject to international quarantine. In the absence of a host, Fusarium oxysporum produces chlamydospores, which can survive in the soil for several years to decades. The pathogen can be transmitted through media such as soil, water, agricultural tools and people, and is highly pathogenic , the infection rate is high, the mortality rate is also high, and the prevention and treatment is extremely difficult. At present, the occurrence of soil-borne banana wilt is mainly slowed down by chemical control, biological control, breeding disease-resistant varieties and some agricultural control measures in production. For nearly a century, domestic and foreign efforts have been devoted to the screening of chemical agents for soil-borne banana wilt, but there is no ideal chemical agent yet. Lin Lanwen and others tested a large number of chemical pesticides, and believed that chemical pesticides had better antibacterial effect on soil-borne banana wilt bacteria indoors, but the control effect in the field was not ideal; Banana Fusarium Wilt has a certain control effect, and other chemical agents are almost ineffective. At present, there are still some reports on the prevention and control of soil pathogenic microorganisms through physical methods and improved cultivation measures. The specific methods mainly include: soil heating, microwave method, crop rotation, rational irrigation, adjustment of planting date and planting density, soil flooding, and burning plants Residues, soil deep plowing, exposure to the sun, and facility planting, such as greenhouses, etc. Soil flooding is currently a commonly used method to create a soil restoration environment, but studies have shown that it takes 3-4 months or longer to reduce the number of pathogenic bacteria in the soil, and the effect is limited. It doesn't even work. In addition, according to the practice of banana producers for many years, neither the application of pesticides nor the treatment of planting soil can effectively prevent the occurrence and expansion of soil-borne banana wilt. The use of disease-free tissue culture seedlings and disease-resistant varieties can not achieve the desired control effect, so the control of soil-borne banana wilt has not yet found an ideal way.

Contents of the invention

The purpose of the present invention is to propose a rapid sterilization method for banana wilt soil-borne pathogenic bacteria in view of a series of practical problems such as high pathogenic bacteria content in the current banana continuous cropping soil, serious occurrence of banana wilt, and poor control methods.

The technical solution adopted by the present invention to solve its technical problems is:

A rapid sterilization method for soil-borne pathogens of banana wilt: First, in continuous cropping soils where continuous cropping obstacles occur or the incidence of banana wilt is high, a strong reduction is created by adding organic carbon sources to the soil and maintaining the anaerobic state of the soil environment, reduce the redox potential of the soil to below -80mV within 72 hours, and then maintain the soil in a strong reducing environment for 2 to 4 weeks to obtain healthy soil with a low content of Fusarium oxysporum Cuban-specific type.

The temperature of the soil is 25-40°C.

When the soil temperature is above 25°C, maintain the soil in a strong reducing environment for 2 weeks.

When the soil temperature is between 15-25°C, maintain the soil in a strong reducing environment for 3-4 weeks.

Further, the organic carbon source is one or a mixture of ethanol, crop stalks, and grass powder.

Further, the method of isolating the exchange of soil with atmospheric gas is flooding and/or covering with plastic film.

Further, the added amount of the organic carbon source is 0.2-0.5 kg C/m ² .

The beneficial effects that the present invention has are:

(1) Anaerobic microorganisms in the soil reproduce in large numbers and produce a large number of anaerobic metabolites, which can quickly and effectively reduce the number of Fusarium oxysporum Cuban specialization in the continuous cropping soil, not only improve the soil microbial flora, but also reduce crop soil-borne diseases to promote crop growth;

(2) For acidified and secondary saline soil, significantly increase soil pH and reduce salt content;

(3) The raw materials are easy to obtain and the cost is low. The use of crop straw as easily degradable organic materials is rich in resources, which can reduce the waste and environmental pollution caused by straw burning, and promote the resource utilization of agricultural waste;

(4) Compared with simple flooding treatment, this method can achieve stronger bactericidal effect in a very short time;

(5) In some soils that are not easy to store water (such as sandy soil), it is easier to use plastic film to create an anaerobic environment in the soil, and the operation will not be caused by the infiltration of water, which will cause the loss of bactericidal substances produced in the anaerobic process. ;

(6) The application prospect is broad. At present, the main banana producing areas in my country, such as Hainan, Guangdong, Guangxi and Yunnan, all have large-scale occurrence of banana wilt. The method of reducing the number of types, short improvement time, low cost, and easy operation has very broad prospects for popularization and application.

Description of drawings

Fig. 1 is the flow chart of the method for quickly killing soil-borne pathogenic bacteria of banana wilt.

Figure 2 is the number of pathogenic bacteria in the soil after different treatment methods, wherein, 1-control untreated soil; Carry out flooding treatment; 4'-this method 1: add low amount (0.2kg C/m ² ) soil of organic material when adopting this method; 4"-this method 2: add high amount ( 0.4kg C/m ² ) soil of organic material.

Fig. 3 is the denaturing gradient gel electrophoresis (DGGE) pattern of control soil, flooding treatment soil and this method processing soil, wherein, 4-this method handles soil, 5-pathogenic bacteria place band, (a) is fungal microflora , (b) bacterial microflora.

Figure 4 is a line graph of the incidence of banana wilt disease in the field experiment of banana garden in Ledong, Hainan in 2014.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, the specific measures for rapid sterilization of soil-borne pathogenic bacteria of banana wilt are as follows: when the ambient temperature is above 25°C, in soil where continuous cropping obstacles occur and the incidence of banana wilt is high, by adding Organic carbon source and isolation of soil and atmospheric gas exchange (flooding or covering with plastic film) make the soil quickly reach a strong reduction state, reduce the soil redox potential to below -80mV within 72 hours, and maintain the soil in a strong reduction state for 2 weeks About (when the ambient temperature is below 25°C, keep the soil in a strong reducing state for 3 to 4 weeks), you can get healthy soil with a low content of Fusarium oxysporum Cuban-specific type. Among them, the banana continuous cropping soil has a concentration of Fusarium oxysporum Cuban specialization higher than 5 × 10 ³ cfu/gram soil; after the treatment by this method, the number of Fusarium oxysporum Cuban specialization in the soil is reduced to 1 of the initial value % ~ 10%.

The principle is that the treatment method of creating a strong reducing environment can quickly promote the reproduction of anaerobic microorganisms in the soil, and the production has been proven to be effective against a variety of soil-borne pathogens, such as Fusarium oxysporum (Fusarium oxysporum), Rhizoctonia solani (Rhizoctonia solani), Ralstonia solanacearum and Phytophthora capsici have a strong inhibitory effect on NH ₃ , H ₂ S and organic acids and other fermentation products; improve the microbial flora of continuous cropping soil, making soil microorganisms There is more diversity. In addition, the growth and metabolism of nitrate-reducing bacteria and sulfate-reducing bacteria in soil were also significantly increased, which promoted the transformation of nitrate and sulfate in secondary salinized soil, reduced soil salinity, and increased the pH of acidified soil.

Since this method achieves the purpose of killing soil-borne pathogenic bacteria and removing salt through the growth and metabolism of anaerobic microorganisms in the soil, this method has certain requirements for soil temperature during the implementation process. Studies have shown that when the soil temperature is between 25 Between 40°C, a better treatment effect can be achieved.

All in all, the implementation of this method can not only reduce the number of soil pathogenic microorganisms, improve soil physical and chemical properties, but also alleviate the pollution of agricultural organic waste. Due to the advantages of high efficiency and environmental protection, this method will have broad application prospects in practical production.

Example:

The purpose of this method is to reduce the number of soil pathogenic bacteria, improve soil microbial flora, and prevent and control banana wilt. The main implementation links are as follows:

In the plots with serious occurrence of banana wilt (as the incidence rate of banana wilt has reached 50%, this plot has been abandoned), add alfalfa grass powder at a concentration of 0.4kg C/ ^m2 , and irrigate until the soil reaches the maximum Cover the plastic film after the field water capacity, and make the soil redox potential drop below -100mV within 48 hours, and maintain the soil in a strong reduction state for 15 days. After 15 days, remove the film and plant bananas. The soil that has not been treated by this method is used as a control.

The results showed that the number of pathogenic bacteria-Fusarium oxysporum in the soil was significantly reduced after the treatment by this method, which was only 5-10% of the control soil content, and the simple flooding treatment could not effectively inhibit the Fusarium oxysporum in the soil in a short period of time. The amount of (Fig. 2); compared with the control soil and the flooded soil, the microbial flora of the soil treated by this technology is more abundant, and the amount of pathogenic bacteria-Fusarium oxysporum in the soil is extremely low (Fig. 3), which is particularly important After planting bananas, compared with the control soil, the soil treated by this technology significantly reduces the incidence of banana wilt and promotes the growth of bananas (Figure 4).

Claims (7)

1. the quick sterilization method of a banana blight soil-borne pathogen, it is characterized in that: first, occurring in continuous cropping obstacle or the higher continuous cropping soil of banana blight sickness rate, strong reducing environment is created by adding organic carbon source and maintain soil anaerobic state in soil, in 72 hours, make the oxidation-reduction potential of soil be reduced to below-80mV, then maintaining soil is strong reducing environment 2 ~ 4 weeks, obtains the healthy soil that Fusarium oxysporum Cuba specialized form content is lower.

2. the quick sterilization method of a kind of banana blight soil-borne pathogen according to claim 1, is characterized in that: the temperature of described soil is 25 ~ 40 DEG C.

3. the quick sterilization method of a kind of banana blight soil-borne pathogen according to claim 1 and 2, is characterized in that: when the temperature of soil is more than 25 DEG C, and maintaining soil is strong reducing environment 2 weeks.

4. the quick sterilization method of a kind of banana blight soil-borne pathogen according to claim 1, is characterized in that: when the temperature of soil is between 15 ~ 25 DEG C, and maintaining soil is strong reducing environment 3 ~ 4 weeks.

5. the quick sterilization method of a kind of banana blight soil-borne pathogen according to claim 1 and 2, is characterized in that: described organic carbon source is the mixture of a kind of or above material in ethanol, crop material, grass meal.

6. the quick sterilization method of a kind of banana blight soil-borne pathogen according to claim 1 and 2, is characterized in that: the method for described maintenance soil anaerobic state is for adopting waterflooding and/or covered with plastic film.

7. the quick sterilization method of a kind of banana blight soil-borne pathogen according to claim 1 and 2, is characterized in that: the addition of described organic carbon source is 0.2 ~ 0.5kg C/m ².