WO2019007300A1 - Method for prevention and control of disease of watermelon - Google Patents

Abstract

Disclosed in the present invention is a method for prevention and control of a disease of watermelon. In the present invention, first, a new symptom of fusarium wilt of watermelon is discovered, and the symptom is that: when cotyledons are unfolded, the seedling is longitudinally split along the hypocotyl from the growth point, and the seedling is infested along the edges of the cotyledons, eventually resulting in death of a grafted seedling; and the pathogens and initial infestation source of the disease are determined. In the present invention, to find a method for prevention and treatment of the disease, tests such as seed coating, seed soaking in medicament, and dry-heat treatment at different temperatures were also carried out, the disease prevention effects of various prevention and treatment methods are analyzed and compared, and finally a most effective method for prevention and treatment of the disease is obtained, to control the occurrence and expansion of the disease, and avoid or minimize the damage and loss.

Description

Method for preventing and controlling watermelon disease Technical field

The invention relates to the field of biological pathogenic bacteria, and particularly relates to a method for preventing and controlling watermelon diseases.

Background technique

The watermelon wilt is widespread worldwide, and its pathogen is Fusarium oxysporum f.sp. niveum, which is a soil-borne and seed-borne disease. Over the years, soil-borne watermelon wilt is an important disease that seriously affects the production of watermelon. The average disease rate is 10% to 20%, and the weight is 80% to 90%, which may even cause production. There are three types of common disease symptoms. (1) Tripping type: occurs in the seedling stage, the seedlings of the melon seedlings lose water and sag, the base of the stem overflows, and finally collapses. (2) Dwarf type: occurs in the vines, the diseased plants grow slowly, the vines are thin, the internodes are short, the skinny, the leaves are yellow and the edges are curled upwards, and the deformed small old seedlings; some of the diseased plants are erect, roots Rarely yellowed, the vascular bundle became brown, and finally died. (3) wilting type: occurs mostly in the melon period, which is a typical symptom of watermelon wilt. According to its manifestation, the whole plant is withered, or the vines on the same plant are withered, some are normal, or the same vine Some ends withered and the other part is normal.

After many years of efforts by agricultural workers at home and abroad, the current soil-borne watermelon wilt can be controlled by techniques such as disease-resistant varieties, crop rotation, soil disinfection, grafting and seeding, and root treatment after planting.

At present, there are few reports on the transmission of watermelon wilt in China and abroad. Boughalleb and other studies have found that seeds can also carry pathogenic bacteria, and the susceptibility rate of watermelon seeds carrying pathogenic bacteria is more than 50% after sowing and planting; Fusarium oxysporum has been isolated from watermelon seeds in China; experiments have shown that the watermelon wilt can be controlled by treating the seeds with fludioxonil.

Invention disclosure

An object of the present invention is to provide a method for controlling watermelon wilt.

The method for controlling watermelon wilt provided by the present invention comprises the steps of dry heat treatment of watermelon seeds;

The watermelon wilt is a watermelon wilt caused by Fusarium oxysporum. The specific manifestation of the disease is that the disease occurs in the seedling stage, and when the seedling cotyledons are unfolded, the longitudinal cracking occurs along the hypocotyl from the growth point, and along the Infecting the leaves of the cotyledons; removing the diseased seedlings during grafting, using the seedlings that have not yet developed the disease, and grafting the film after the film is moisturized, the grafted seedlings can still be found in the onset of the disease, and the diseased plants become the center of the disease, so that the disease continues to the surrounding area. Plant expansion, grafting methods can not prevent the death of the diseased scion. The rate of sick and dead seedlings is up to 80% at the time of transplanting.

In the above method, the propagation route of the watermelon wilt is a seed transmission.

In the above method, the dry heat treatment is carried out by dry-treating the watermelon seeds at (30-35) °C for 24 hours; then drying at (45-50) °C for 24 hours; finally at (78-82) °C. Dry heat treatment under conditions of 72-96h. In a specific embodiment of the present invention, the dry heat treatment method comprises the following steps: dry-treating the watermelon seeds at 35 ° C for 24 h; then drying at 50 ° C for 24 h; and finally drying at 80 ° C (72 °). 96) h.

Still another object of the invention is to provide a new use of the above method.

The invention provides the application of the above method in improving the control effect of watermelon wilt.

The invention also provides the use of the above method for reducing the incidence of plants of watermelon wilt.

The invention also provides the use of the above method in controlling the occurrence and development of watermelon blight.

In the above application, the watermelon wilt is a watermelon wilt caused by Fusarium oxysporum.

In the above application, the transmission route of the watermelon wilt is a seed transmission.

Since 2016, a new seedling disease has begun to appear in the production of watermelon in China. The present invention first discovered that the watermelon disease has new symptoms of watermelon wilt disease, which is manifested as follows: when the cotyledon is unfolded, it starts from the growth point along the hypocotyl Longitudinal cracking, at the same time, infestation along the edge of the cotyledon, grafting method can not prevent the death of the diseased scion, the disease killing rate is as high as 80%, resulting in devastating loss during the seedling period. After reviewing the domestic and foreign materials, there was no report on the symptoms of the disease. So, the typical disease samples were collected and the morphology and molecular identification were carried out. The results showed that the pathogen of the disease was Fusarium oxysporum, and the seed test was carried out, and the disease was found to be one. Various kinds of watermelon wilt disease. Finally, in order to find out the prevention and treatment methods of the disease, seed coating, chemical soaking and dry heat treatment tests at different temperatures were carried out, and the incidence and disease prevention effects of different treated seeds were analyzed and compared, and finally the disease was prevented. The most effective method to achieve the control of the occurrence and spread of the disease from the source, to avoid or to minimize the loss of the transmission of watermelon wilt to production.

DRAWINGS

Figure 1 shows the symptoms of watermelon wilt. From left to right, the diseased watermelon seedlings, diseased scions and diseased grafted seedlings.

Figure 2 shows the morphology of conidia of Fusarium oxysporum. From left to right, they are large conidia and conidiophores.

The best way to implement the invention

The experimental methods used in the following examples are conventional methods unless otherwise specified.

The materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

The watermelon varieties "Jingxin 307" and "Jing Ying" in the following examples were purchased from Jingyan Yinong (Beijing) Seed Industry Technology Co., Ltd.

The test reagents in the following examples were 6.25% refined metalaxyl · fluke nitrile suspension seed coating agent, 2.5% fludioxanil suspension seed coating agent and 50% fludioxon WP wettable powder, all of which are Syngenta of Switzerland. Crop Protection Co., Ltd. products.

The CLA medium in the following examples is a medium obtained by placing a sterilized 3 to 5 mm ² carnation leaf section into a culture dish, and then adding a 2% water agar medium (formulation: 1 L of water, 20 g of agar), usually per Add 2 to 5 mm ² carnation leaves in 2 mL medium.

The PDA medium in the following examples was a medium obtained by mixing 200 g of potatoes, 20 g of glucose, 17 g of agar, and 1000 mL of distilled water.

The PL medium in the following examples was a medium obtained by mixing 200 g of potatoes, 20 g of lactose, and 1 000 mL of distilled water.

Example 1. A new watermelon wilt disease caused by Fusarium oxysporum

First, the discovery and symptoms of the disease

At the beginning of 2016, a new watermelon wilt disease appeared in the main watermelon producing areas of China. The disease occurs in the nursery stage, and the disease manifests itself: when the cotyledons are unfolded, they are longitudinally split along the hypocotyl from the growth point, and at the same time, infested along the edge of the cotyledon. It is observed that when the seedlings are unearthed for about 10 days, the number of seedlings reaches 30%; when grafting, the diseased seedlings are removed, and the seedlings that have not yet been infected are used for grafting. After the film of the film moisturizing is uncovered, the grafted seedlings can still be found in the onset of the disease, and the diseased plant becomes the center of the disease, so that the disease continues to expand to the surrounding plants, and the scion The disease eventually leads to the death of the grafted seedlings. During the period from the emergence of the seedlings, the drug has been used for prevention and treatment. The trial of a variety of agents has little effect, and the rate of diseased dead seedlings is as high as 80% before transplanting. The whole batch of seedlings could not be used.

Second, the collection of diseased materials and the isolation and purification of pathogenic bacteria

Pathogens were isolated and purified from the diseased seedlings with typical diseased leaves according to a conventional method, and one isolate was obtained, and the isolate was named XG1601. The specific steps are as follows: collect the typical diseased seedlings, cut the tissue of the diseased junction at a length of about 5 mm, dip with 70% alcohol for a few seconds, wash with sterile water for 3 times, use a sterile filter paper to absorb the water, and then place The PDA plate was cultured at 25 ° C; after 2-3 days, the mycelium was picked from the edge of the formed colony and transplanted onto a new PDA plate; after 2-3 days, the conidia production was observed with a microscope. The spores produced on the strain were washed with sterile water and diluted to several concentration gradients. 1 mL of different concentrations of spore suspension were applied to 1% water agar medium (1% water agar medium was 10 g agar and 1 L water). The surface of the obtained medium was mixed, and the spores were examined from the front of the water agar plate under a microscope, and single spores were picked and cultured on a PDA plate to obtain an isolate XG1601.

3. Pathogenicity determination and morphological and molecular identification of pathogenic bacteria

1. Pathogenicity determination of pathogenic bacteria

(1) Strain preparation

The isolated and purified isolate XG1601 was inoculated on PDA medium and cultured at 28 ° C for 5 days. Add appropriate amount of water to the PDA plate culture of XG1601 and stir it into a slime. Mix it with the test watermelon seeds (the test watermelon variety is “Jingying”), and inoculate 30% of the bacteria per 1/2 plate. Grain seeds.

(2) Seedling preparation

Take a small nursery box, sterilized vermiculite at the height of 2/3 seedling box at the bottom, 30 seeds of watermelon seeds inoculated with isolate XG1601 on the second layer, and 3 layers of sterilized vermiculite covering 1/3 of the height of the seedling box Seeds that were not inoculated with pathogens were used as controls. The seedling box was placed in a 25 ° C light incubator at a constant temperature, and the daylight was irradiated for 12 hours every day to check the emergence of seedlings and seedlings.

The results showed that the seedlings inoculated with the isolates continued to develop on the 9th day after sowing, while the control seedlings did not develop disease. The pathogens isolated from the inoculated seedlings were isolated and the pathogens were identical in morphology, so it was determined. The isolate XG1601 is a pathogenic bacterium.

2. Morphological identification of pathogenic bacteria

The isolated and purified isolate XG1601 was inoculated onto a PDA plate, cultured in the dark at 25 ° C, and the colony morphology was observed; cultured on a CLA medium, large conidia, small conidia and chlamydospores were observed, and the microscope was inverted at 100 times. The direct production of small conidia was directly observed and identified based on relevant classification data.

The morphology of large conidia and conidiophores of pathogenic bacteria is shown in Figure 2. The pathogen was pinkish white on the PDA medium, the colony was round, and the mycelium was fluffy. It was cultured in dark on PDA at 25 °C, and the diameter of the colony reached 77 mm in 7 days. The large conidia scab was mainly composed of three membranes. Small conidia long elliptic, usually without septum; conidiophores short, borne on the side of hyphae, solitary, unbranched; sclerotium spores terminal or internate, round, mostly sessate, occasionally Pair or cross. According to The Fusarium Laboratory Manual (Leslie et al., 2006), the pathogen was identified as Fusarium oxysporum.

3. Molecular identification of pathogenic bacteria

(1) DNA extraction

The isolated and purified isolate XG1601 was inoculated into PL medium, cultured at 25 ° C, 125 rpm·min ^-1 for 3 to 4 days, and the mycelium was collected by filtration, and the strain DNA was extracted by a modified CTAB method.

(2) PCR amplification

Using the DNA obtained in the above step (1) as a template, the rDNA-ITS region of the pathogen was subjected to PCR amplification using the fungal ribosomal gene transcribed spacer (ITS) universal primer ITS1/ITS4 to obtain a PCR amplification product.

PCR amplification conditions: pre-denaturation at 94 ° C for 5 min; denaturation at 94 ° C for 1 min, annealing at 57 ° C for 1 min, extension at 72 ° C for 1 min, a total of 30 cycles; finally extending at 72 ° C for 10 min.

(3) Sequence analysis

The obtained PCR amplification products were sequenced by Beijing Sanbo Yuanzhi Biotechnology Co., Ltd., and the obtained sequences were aligned in GenBank, and the pathogens were identified by BLAST search and homology analysis.

The sequencing results showed that a DNA fragment of 504 bp in size was obtained by PCR amplification, and the nucleotide sequence thereof was as shown in SEQ ID NO: 1. Sequence alignment homology analysis by BLAST showed 99% sequence homology with Fusarium oxysporum such as KC201696 in GenBank.

Based on the above identification results, the pathogen was identified as Fusarium oxysporum. Therefore, the pathogen of the watermelon seedling disease in the first step is Fusarium oxysporum.

Example 2 Prevention and treatment method of watermelon seed wilt disease caused by Fusarium oxysporum

The watermelon seedling disease that occurred in early 2016, after grafting, continues to develop, and the diseased plant has become the center of disease, so that the disease continues to expand to surrounding plants. Therefore, the grafting method does not help to control this watermelon disease; In the field investigation, the substrates and utensils used in the nursery were all sterilized. Therefore, it is preliminarily judged that the pathogen of the disease should be derived from the seed, that is, the seed carries the pathogenic bacteria. Therefore, it is necessary to carry out the detection of the internal bacteria in the seed and carry out research on the seed treatment method. The specific method is as follows:

First, the preparation of seeds carrying germs

1. Preparation of spore suspension of isolate XG1601

The isolate XG1601 of Example 1 was first inoculated on a PDA plate, and after culturing at 25 ° C for 4 days, 3 to 4 0.5 cm ² pieces were picked and placed in a PL medium at 25 ° C, 110 r·min in a shaker. ^-1 culture for 5-7d, then filter the bacterial solution with sterile four-layer gauze, centrifuge at 6000r·min ^-1 for 15min, discard the supernatant, add appropriate amount of sterilized water to dilute the spores, count with the blood cell counting plate, and finally adjust A spore suspension of the isolate XG1601 was obtained at a spore concentration of 1 × 10 ⁴ · mL ^-1 .

2. Preparation of seeds carrying germs

Soak the watermelon seeds ("Jingxin 307") with the spore suspension of the isolate XG1601. After 6 hours, remove the water control and sow in the tray with the sterilization substrate (petroleum: vermiculite = 2:1). When transplanted to the test shed, it will be routinely managed until the watermelon is ripened. The harvested whole batch of seeds were uniformly mixed and stored at room temperature, and used as test watermelon seeds in the following seed test and control method test.

Second, seed detection

The internal bacteria test was carried out: 250 samples of watermelon seeds were randomly selected and soaked in 1% sodium hypochlorite solution for 1 min, then rinsed with sterile water for 3 times. Two layers of sterile filter paper were placed on the bottom of the culture dish, and the seeds were poured into it. Using sterile filter paper to dry the sterile water on the surface of the seed; then dissecting the seed into seed coat and seed embryo with a sterile scalpel, and evenly placing the seed coat (inside) and the embryo on the PDA plate with a diameter of 15 cm On the top, 20 seed coats or seed kernels were placed in each plate; the cells were cultured in a dark state at 25 ° C in an incubator, and recorded after 7 days. Repeat 4 times and the results are averaged. The rate of seeded Fusarium oxysporum (%) = (number of Fusarium oxysporum seeds / total number of detected seeds) × 100%.

The results showed that the average rate of Fusarium oxysporum in the seed coat was 5.4%, and the rate of Fusarium oxysporum in the embryoids was 1.7%.

The pathogenicity and morphology of the detected Fusarium oxysporum were identified. The results showed that the pathogenicity and morphological identification results were the same as those of the isolate XG1601 in Example 1, and it was judged that the disease was a seed-borne disease. Therefore, sterile seeds are the main measure to prevent the occurrence of the disease, and its prevention and treatment should start from seed treatment.

Third, the prevention and treatment method of watermelon seed-borne wilt disease caused by Fusarium oxysporum

1, seed coating treatment

Choose two kinds of coating agents which are effective in the prevention and treatment of Fusarium oxysporum on the market: 6.25% refined metalaxyl · chlorflunan nitrile suspension seed coating agent (bright shield) and 2.5% oxystonitrile suspension seed coating agent (School) At the time of the coating, the test watermelon seeds were coated at a ratio of 1:250. The specific steps of the coating treatment are as follows: the seed is placed in a good plastic bag or a ziplock bag, and the seed coating agent is diluted 5 times with tap water in a beaker, and then the diluted liquid is quickly poured into the bag. Hold the bag mouth (let enough air in the bag), shake the seed up and down quickly, and wrap the liquid on the surface of the seed. All treated seeds were placed in the house for dryness and used directly for testing, with uncoated seeds as controls. Three replicates, each repeating 30 seeds (30 seeds/box). The treated seeds were first placed in a growth chamber at a constant temperature of 25 ° C, 12 hours light / 12 hours dark, and moved to the greenhouse after emergence. After sowing seedlings, the incidence was investigated daily, and the investigation was completed 35 days after sowing, and the incidence and control effects were calculated. Control effect (%) = (control incidence - treatment incidence) / control incidence × 100; incidence (%) = number of seedlings / total number of seedlings × 100.

The results are shown in Table 1. As can be seen from Table 1, the incidence of control was 56.6%, and the incidence of coating with Liangdun and Shire was 18.7% and 17.8%, respectively. Compared with the control, the coating with Bright Shield and Shira has a certain control effect, and the control effects are 66.97% and 68.56%, respectively.

Table 1. Incidence of plants after bacterial seed coating treatment (%)

2, drug soaking treatment

The 50% flavonoid wettable powder 4000 times solution was used to immerse the tested watermelon seeds in the following two ways: one treatment was to dip the seeds for 4 hours, then change the water to germination; the other was to first soak the seeds with water. Before sowing, use the liquid to soak for 0.5h. The amount of liquid medicine used must be such that the seeds are completely submerged. The seeds treated with the non-medicated seeds were used as controls. 72 holes, 7 plates per treatment, the number of seeds is 504, and the cultivation substrate is sterilized vermiculite. In the solar greenhouse, the geothermal line is heated at night and the set temperature is 25 °C. The incidence of the disease was investigated daily after sowing, and the number of diseased plants was recorded and the diseased plants were cleaned up in time. The investigation was terminated 50 days after sowing.

The results are shown in Table 2. It can be seen from the table that the seed treated with the chemical solution has a relatively early onset, and the rate of susceptible strains is relatively high. The time of onset of soaking for 4 hours and 0.5 h of immersion buds is later, and the rate of susceptible strains is lower than that of the control. However, the control effects were 17.5% and 11.3%, respectively, and the control effect was very low. The flax nitrile wettable powder 4000 times liquid treatment of the seed, although the highest concentration used, but still can not completely control the disease, it can be seen that the use of sputum nitrile soaking and germination can not achieve the purpose of prevention and control of the disease.

Table 2. Incidence of plants after treatment with infected seeds (%)

3, seed dry heat treatment

The dried watermelon seeds were subjected to dry heat treatment. After dry heat treatment, the power was turned off. After 24 hours, the seeds were taken out and placed in a storage box, and the seeds which were not dried by heat treatment were used as controls. A total of 1000 dry heat-treated seeds were seeded in a 72-well plate, and the incidence was recorded daily from the emergence of the seedlings, and the diseased plants were removed in time until 50 days after sowing. The specific steps of the dry heat treatment are as follows: The seeds are placed in a dry heat treatment machine (2100 L produced by Korea Korea Instruments Co., Ltd.), and are classified into the following groups according to the treatment time and temperature:

Treatment group 1 (treated at 72 ° C for 96 h): the watermelon seeds were sequentially subjected to the following dry heat treatment: dry heat treatment at 35 ° C for 24 h; dry heat treatment at 50 ° C for 24 h; dry heat treatment at 72 ° C for 96 h;

Treatment group 2 (treated at 72 ° C for 120 h): the watermelon seeds were sequentially subjected to the following dry heat treatment: dry heat treatment at 35 ° C for 24 h; dry heat treatment at 50 ° C for 24 h; dry heat treatment at 72 ° C for 120 h;

Treatment group 3 (80 ° C treatment for 72 h): the watermelon seeds were sequentially subjected to the following dry heat treatment: dry heat treatment at 35 ° C for 24 h; dry heat treatment at 50 ° C for 24 h; dry heat treatment at 80 ° C for 72 h;

Treatment group 4 (treated at 80 ° C for 96 h): The watermelon seeds were sequentially subjected to the following dry heat treatment: dry heat treatment at 35 ° C for 24 h; dry heat treatment at 50 ° C for 24 h; and dry heat treatment at 80 ° C for 96 h.

(1) Test results of dry heat treatment at 72 ° C

The results are shown in Table 3. It can be seen from the table that after the dried heat treatment at 72 °C for 96 hours, the incidence rate decreased from 35.71% of the control to 18.18%, and the control effect was 49%; the control effect was not good. After the dry heat treatment at 72 °C was extended to 120 h, the incidence rate decreased from 35.71% of the control to 15.86%, and the control effect was 55.5%. The control effect was still low. Therefore, under the condition of dry heat treatment at 72 °C, prolonging the treatment time can not improve the control effect.

Table 3. Incidence of plants after heat treatment of dried seeds (%)

(2) Test results of 80 ° C dry heat treatment

The results are shown in Table 4 (daily survey results, only partial). On the eleventh day after sowing, the diseased plants began to appear until the plant appeared 50 days after sowing. On the 15th day, the incidence rate was 31.9%. On the 20th day, the incidence rate reached 40.2%. On the 30th day, the incidence rate reached 51.5. %, on the 40th day, the incidence rate reached 70.5%, on the 50th day, the incidence rate reached 80%; after 80 °C 72h treatment, the incidence rate was only 0.4% within 50 days after sowing; after 80 °C 96h treatment seed sowing There were no diseased plants within 50 days, and the incidence rate was 0. It can be seen from the above results that the seed treated at 80 ° C for 72 h greatly reduced the incidence and the control effect was 99.5%; while the seed treated at 80 ° C for 96 h, the incidence rate was zero within 50 days after sowing, and the control effect was 100%. It is indicated that the 80 °C dry heat treatment is effective for controlling the disease, and the control effect at 80 °C for 72-96 h is 99.5-100%.

Table 4. Incidence of plants after heat treatment of dried seeds (%)

In summary, the dry heat-treated seeds at 72 °C for 96-120h, the control effect is 49.0-55.5%; the dry heat-treated seeds at 80 °C for 72-96h, the control effect is 99.5-100%. By comprehensively comparing the above results, it can be seen that the control effect of the dried heat-treated seeds at 80 ° C is the best.

Example 3: Effect of seed dry heat treatment on seed vigor and seedling growth

After treatment of watermelon Jingxin 307 seeds with good control effect (80 °C 72h and 80 °C 96h), the germination test was carried out to determine the effect of dry heat treatment on the vigor and seedling growth potential of watermelon Jingxin 307 seeds. Heat treated watermelon Jingxin 307 seeds were used as control (CK). The specific steps are as follows: the seeds after dry heat treatment are directly sown in the sterilized vermiculite, and placed under the condition of constant temperature of 25 ° C, L//D=12h//12h, and seeded from the seedlings after sowing, and the seedlings are investigated every day. Situation, record the emergence time. Repeat 100 times for each 100 seeds processed. The germination potential of the seeds was calculated 5 days after sowing, the seed emergence rate of the seeds was calculated 14 days, and the growth characteristics of the seedlings were determined 14 days. When measuring the growth characteristics of the seedlings, the seedlings were extracted from the roots, washed with water, placed on a filter paper to absorb excess water, and the total weight of each repeated seedlings was weighed to calculate the average fresh weight per plant. Data results were analyzed using a one-way ANOVA model and the significance of the mean difference was tested using SNK (Student-Newman-Keuls, P=0.05) (SPSS Inc. 2008).

The results are shown in Table 5. It can be seen from Table 5 that compared with the control group (CK), the seed germination potential, emergence rate and fresh weight were not affected after the seeds were treated at 80 ° C for 72 h or 96 h.

Table 5. Seed quality and seedling growth

deal with	Germination potential (%)	Seedling rate (%)	Fresh weight (g) / strain
CK	100Aa	100Aa	0.385Aa
80 ° C 72h	96Aa	99Aa	0.3898Aa
80 ° C 96h	98Aa	99Aa	0.3884Aa

Note: The same uppercase and lowercase letters after the same column data indicate that the difference is not significant at the P<0.01 and P<0.05 levels by the Student-Newman-Keuls test.

Industrial application

The invention firstly discovers a new symptom of watermelon wilt. The symptom is: when the cotyledon is unfolded, it is longitudinally split along the hypocotyl from the growth point, and at the same time, infects along the edge of the cotyledon, and finally leads to the scion of the grafted seedling. Death; and confirmed the pathogen and initial infection source of the disease. In order to find the prevention and treatment method of the disease, the invention also carries out seed coating, chemical soaking and dry heat treatment test at different temperatures, and analyzes and compares the prevention effects of various control methods, and finally obtains the most effective prevention and treatment of the disease. The method comprises the steps of: performing dry heat treatment on the watermelon seed; the dry heat treatment is carried out by dry-treating the watermelon seed at (30-35) ° C for 24 h; then drying at (45-50) ° C for 24 h; Finally, dry heat treatment (72-96) h at (78-82) °C. The prevention and control method of the invention can effectively control the occurrence and expansion of the disease, avoiding or minimizing the harm and loss caused by the disease.

Claims (9)

1. A method for controlling watermelon wilt, comprising the steps of dry heat treatment of watermelon seeds;

   The watermelon wilt is a watermelon wilt caused by Fusarium oxysporum.
2. The method according to claim 1, wherein the path of transmission of the watermelon wilt is a seed transmission.
3. The method according to claim 1 or 2, wherein the dry heat treatment is performed by dry-treating the watermelon seeds at (30 to 35) °C for 24 hours; then drying at (45 to 50) °C. Heat treatment for 24 h; finally dry heat treatment (72-96) h at (78-82) °C.
4. The method according to claim 3, wherein the dry heat treatment comprises the steps of dry-treating the watermelon seeds at 35 ° C for 24 h; then drying at 50 ° C for 24 h; and finally drying at 80 ° C. Heat treatment (72 ~ 96) h.
5. Use of the method according to any one of claims 1 to 4 for improving the control effect of watermelon wilt.
6. Use of the method according to any one of claims 1 to 4 for reducing the incidence of plants of watermelon wilt.
7. Use of the method of any of claims 1-4 for controlling the occurrence and development of watermelon blight.
8. The use according to any one of claims 5-7, characterized in that the watermelon wilt is a watermelon wilt caused by Fusarium oxysporum.
9. The use according to claim 8, characterized in that the propagation route of the watermelon wilt is a seed transmission.

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