Method for preventing and controlling ditylenchus destructor in cellaring period of crops

Abstract

The invention discloses a method for preventing and treating ditylenchus destructor in a cellaring period of crops, and belongs to the technical field of pest control. The crops are treated at the temperature of 35-41 DEG C, and the treatment time is more than one day. According to the method provided by the invention, the crops are treated at the temperature of 35-41 DEG C, the harm of the ditylenchus destructor to the crops is efficiently solved, the operation method is simple, the operation cost is low, and the problem that the ditylenchus destructor generates drug resistance by using a chemical prevention and control method in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of pest and disease control technology, and more specifically to a method for controlling stem nematodes that cause crop rot during storage. Background Technology

[0002] Stem rot nematode is a polyphagous nematode belonging to the genus *Heterocereus* of the family Granulidae in the order Nematoda. More than 90 plant host species have been reported. Potato is its primary host, with other important host crops including sweet potato, onion, garlic, iris, and tulip. It is the most significant disease affecting potatoes. Without control measures, its damage to sweet potatoes and ginseng can sometimes be devastating, leading to total crop failure.

[0003] Potatoes, also known as spuds, are annual herbaceous tuberous plants belonging to the Solanaceae family and the Solanum genus. They are used as grain, vegetable, and forage, and are characterized by strong adaptability, high yield, comprehensive nutrition, and a long industrial chain. They are the most abundant raw material crop for processed products in agricultural production and the world's fourth largest food crop, holding an important position in agricultural production. Potatoes are also one of the main winter vegetables consumed by urban residents in northern China, historically holding a major share in winter vegetable storage. Stem rot nematodes (… Ditylenchus destructor Thorne Stem rot nematode is an important pathogen causing disease during potato storage and is also an important global quarantine pest. During potato storage, potatoes are often damaged by stem rot nematodes. Once infected with stem rot nematodes, mild cases may cause scattered rotting of potato tubers, while severe cases may cause the storage cellar to rot, resulting in serious losses.

[0004] Potato stem rot nematode disease is a serious disease that occurs during potato storage, severely affecting potato quality and hindering long-term storage, posing a significant threat to the potato industry. Currently, due to early storage of potatoes and extensive management practices, stem rot nematode disease is difficult to control once it occurs. In production, chemical control methods using pre-mixed pesticide powders are commonly used. However, this method easily leads to pesticide resistance in the stem nematodes, resulting in low control efficiency. Furthermore, while existing technologies include temperature-based treatment methods for stem rot nematodes, the nematodes' minimum survival temperature is -28°C. At temperatures above 35°C, they only cease activity but do not die, resulting in low control efficiency; therefore, chemical control methods are still necessary. Summary of the Invention

[0005] This invention provides a method for controlling stem nematodes during crop storage, which solves the problem that existing chemical control methods are prone to developing resistance and are difficult to control effectively.

[0006] A method for controlling stem nematodes during crop storage involves treating crops at a temperature of 35℃~41℃ for 1 to 11 days, followed by storage in a cellar. The crop is potato or iris root.

[0007] Preferably, the temperature is 37-41 DEG C, and the treatment time is 3-11 days.

[0008] Preferably, the temperature is 37-39 DEG C, and the treatment time is 3-5 days.

[0009] Preferably, the temperature for the storage is 2-8 DEG C.

[0010] Preferably, the humidity for the storage is 60-90%.

[0011] Preferably, the oxygen volume concentration in the environment for the storage is 3-5%.

[0012] Preferably, the cellar used for the storage is a cellar.

[0013] Preferably, the cellar is a soil cellar or a brick cellar.

[0014] Compared with the prior art, the present application has the advantages of: The present application finds that when the rot stem nematode is treated with 43 DEG C dry heat for 1h or 49 DEG C hot water for 10 min, the nematode is all dead, and the mortality is not obvious when the temperature is less than 43 DEG C. The present application also finds that when the temperature is greater than 43 DEG C, the weight loss rate of the potato increases, and brown spot phenomenon appears, which will affect the quality of the potato. Therefore, how to kill the rot stem nematode without deteriorating the potato during the storage period is the key problem to be solved by the present application.

[0015] The present application finds that when the temperature is 35-41 DEG C and the treatment time is 1-11 days, the rot stem nematode can be effectively killed, and the nematode is all dead, and the treatment condition has no significant effect on the growth condition of the healthy potato, and can be used for preventing and treating the rot stem nematode disease during the storage period of the potato. In the present application, when the temperature is 35-41 DEG C and the treatment time is 1-11 days, the protein of the rot stem nematode is denatured, and the enzyme system is inactivated, while 35-41 DEG C only induces a short-term stress response for the potato. During the stress response, the ROS of the potato exosmosis or local microenvironment oxidative stress, the antioxidant system of the nematode is overloaded, and the oxidative damage is directly caused to the cell membrane and enzyme system of the nematode, accelerating the death of the nematode; the potato rapidly repairs the protein through HSPs, but the HSP response of the nematode is weak, and cannot resist the continuous heat stress, resulting in the accumulation of protein denaturation of the nematode; the soluble sugar of the potato is rapidly consumed under the stress, resulting in the reduction of the available nutrients of the nematode, accelerating the energy exhaustion and death of the nematode, and therefore, the stress response of the potato further causes the death of the rot stem nematode under the condition of 35-41 DEG C.

[0016] The present application does not appear rot nematode after 180 days of storage after treatment at a temperature of 35-41 DEG C for 1-11 days, the rot nematode in the potato is killed by high temperature first, and then the potato is transferred to the cellar for storage, so that the rot nematode is avoided to breed during the storage period, and the prevention and control effect of the rot nematode is ensured.

[0017] In addition, the short-term stress biochemical reaction induced by the potato protects the integrity of the cell membrane from being damaged, maintains normal activity through the physiological protection mechanism during the dormant period, and the present application utilizes the difference in heat resistance between the rot nematode and the potato to achieve the dual goals of high-efficiency pest control and crop safety without using chemical control.

[0018] The prevention and control method provided by the present application can also effectively kill the rot nematode in the iris root without affecting the normal growth of the iris root, and can be used for preventing and controlling the rot nematode disease of the iris root. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The survival rate of rot nematode after treatment at different temperatures for different time.

[0020] Figure 2 The survival of nematodes in the tuber.

[0021] Figure 3 The weight loss rate of the potato.

[0022] Figure 4 The heat damage rate of the potato, and the results are the results of two parallel experiments.

[0023] Figure 5 The germination rate of the potato. DETAILED DESCRIPTION

[0024] The specific embodiments of the present application will be described in detail below, but it should be understood that the protection scope of the present application is not limited by the specific embodiments. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present application. The experimental methods described in the embodiments of the present application are all conventional methods unless otherwise specified.

[0025] To solve the problem of serious damage of rot nematode and difficult effective prevention and control in the prior art, the present embodiment provides a prevention and control method for rot nematode in crops.

[0026] The crops are treated at a temperature of 35-41 DEG C, and the treatment time is more than 1 day.

[0027] The technical solutions of the present application will be further described below in combination with specific embodiments.

[0028] Embodiment 1 A method for controlling Ditylenchus destructor in potatoes, wherein the potatoes are stored at 35°C for 7 days.

[0029] Example 2 A method for controlling Ditylenchus destructor in potatoes, wherein the potatoes are stored at 37°C for 3 days.

[0030] Example 3 A method for controlling Ditylenchus destructor in potatoes, wherein the potatoes are stored at 39°C for 1 day.

[0031] Example 4 A method for controlling Ditylenchus destructor in potatoes, wherein the potatoes are stored at 41°C for 1 day.

[0032] Example 5 A method for controlling Ditylenchus destructor in potatoes, wherein the potatoes are stored at 35°C for 3 days.

[0033] Example 6 A method for controlling Ditylenchus destructor in potatoes, wherein the potatoes are stored at 39°C for 3 days.

[0034] Example 7 A method for controlling Ditylenchus destructor in potatoes, wherein the potatoes are stored at 37°C for 5 days.

[0035] Example 8 A method for controlling Ditylenchus destructor in potatoes, wherein the potatoes are stored at 39°C for 5 days.

[0036] Verification test This example provides the isolation and culture of Ditylenchus destructor.

[0037] Potatoes carrying Ditylenchus destructor collected from Jingbian County, Yulin City, Shaanxi Province were cleaned, cut into small pieces, and a section of rubber tube was connected to the end of a funnel with a diameter of 20 cm. A spring clamp was clamped at the rear end of the rubber tube, a layer of iron mesh was placed in the funnel, two layers of gauze were placed on the iron mesh, and a layer of nematode filter paper was placed on top. 100 g of the cut potato material was evenly spread on the filter paper, water was added to immerse the sample, and the sample was isolated at 20°C for 24 h. The spring clamp was opened, the water in the rubber tube was discharged into a small beaker, and then the filtrate was collected by passing through three sieves. The filtrate was filtered again in a funnel with a layer of nematode filter paper, and after standing for 8 h, the supernatant was siphoned off, and about 50 mL of nematode suspension was retained at the bottom. The nematode suspension was centrifuged to obtain a nematode suspension with a concentration of about 10,000 individuals / mL. The nematode suspension was inoculated on healthy tobacco-sweet potato No. 25 commercial potatoes for culture and propagation to obtain the nematode source.

[0038] 1. Survival rate test of Ditylenchus destructor after different temperature and time treatments The nematode fluid obtained in Example 1 was used to prepare a nematode suspension of approximately 100 nematodes / mL. 500 μL of the nematode suspension was transferred to a 1.5 mL centrifuge tube and randomly divided into four groups: 33℃, 35℃, 37℃, 39℃, and 41℃ treatments, and a control at 28℃. The nematode fluid for each treatment was placed at the corresponding temperature, with all other conditions identical except for temperature. Each treatment was randomly divided into five time groups, meaning the nematode fluid was placed at each of the above temperature groups for 8 h, 1 d, 3 d, 5 d, 7 d, and 9 d. Each group had three replicates. At each time point, the nematode fluid from each group was collected, and the number of nematodes was counted. The average value of the three replicates was taken to calculate the mortality rate of the nematodes at each time point under different temperature treatments, as shown below. Figure 1 The mortality rate of stem nematodes varies at different temperatures.

[0039] like Figure 1 As shown, the survival rate of stem rot nematodes decreased significantly compared to the control with prolonged treatment at temperatures ranging from 33℃ to 41℃. At 39℃ and 41℃ for 24 hours and 8 hours respectively, all nematodes died. At 37℃ for 1 day, the survival rate significantly decreased to 30.08%, and after 3 days, all nematodes died. At 35℃ for 1 day, the survival rate was 65.96%; after 3 days, the survival rates were 18.75% and 81.15% respectively; and after 5 days, all nematodes died. At 33℃ for 1 day, the survival rate was 84.01%, and after 9 days, it was 62.63%. The results indicate that stem rot nematodes are sensitive to temperature and intolerant of high temperatures.

[0040] 2. Survival status of nematodes inside potato tubers Potatoes infected with stem nematodes were treated at 35℃, 37℃, and 39℃ for 3 days, 5 days, and 7 days, respectively, and the survival of nematodes inside the tubers was observed.

[0041] Survival status of nematodes inside potato tubers as follows Figure 2 As shown, a large number of nematodes survived in the control group, with 58.33±7.51 nematodes per unit area of ​​1mm×1mm. However, all nematodes in the potato tubers treated with high temperatures of 35℃, 37℃, and 39℃ died, with zero nematodes per unit area of ​​1mm×1mm.

[0042] 3. Weight loss rate of potatoes after high-temperature treatment High-temperature treatment leads to weight loss in potatoes, mainly due to the loss of water and nutrients. To observe the weight loss rate of potatoes, the weight loss rate was calculated under the following conditions: 35℃ for 3, 5, 7, 9, and 11 days; 37℃ for 3, 5, 7, 9, and 11 days; and 39℃ for 3, 5, 7, 9, and 11 days.

[0043] Depend on Figure 3 It can be seen that, under the same temperature treatment, the weight loss rate of potatoes gradually increased with the extension of treatment time. At 35℃ for 3d, 5d, 7d, 9d, and 11d, the weight loss rates were 4.57%, 5.41%, 6.45%, 7.90%, and 9.25%, respectively; at 37℃ for 3d, 5d, 7d, 9d, and 11d, the weight loss rates were 4.79%, 6.22%, 7.32%, 8.56%, and 10.75%, respectively; and at 39℃, the weight loss rates were 4.96%, 6.97%, 8.31%, 9.75%, and 12.47%, respectively. The weight loss rate of potatoes also increased with increasing treatment temperature.

[0044] 4. Temperature treatment of healthy potatoes to statistically analyze heat damage rate To observe whether brown spots appear inside potatoes under temperature treatment, healthy potatoes were placed at 37℃ for 3d, 5d, 7d, 9d, and 20d, and at 39℃ for 3d, 5d, 7d, 9d, and 11d, and the phenomenon of brown spots inside potatoes was observed under the above conditions.

[0045] like Figure 4 As shown, healthy potatoes placed at 37℃ for 3, 5, 7, and 9 days did not develop brown spots inside. After 20 days, the internal tissue of the tubers turned light brown. Potatoes placed at 39℃ for 3, 5, and 7 days did not develop brown spots inside. However, after 11 days, brown spots due to heat damage appeared inside the tubers.

[0046] 5. Effect of high-temperature treatment on potato sprouting rate Potatoes were treated at 37℃ and 39℃ for 3 days, 5 days, and 7 days respectively, then stored at 4℃ for 120 days, and then placed at room temperature for 30 days. The germination rate and germination grade were then recorded.

[0047] Germination rate, such as Figure 5 As shown, the germination rate of tubers treated at 37℃ for 3 days, 37℃ for 5 days, and 39℃ for 5 days was 100%, while the germination rates at 37℃ for 7 days, 39℃ for 3 days, and 39℃ for 9 days were 90.91%, 93.75%, and 96.43%, respectively.

[0048] The germination grade number was 0.806 for the control, 0.8 for both 3 days and 5 days at 37℃, 0.636 for 7 days at 37℃, and 0.896, 0.875, and 0.667 for 3 days, 5 days, and 7 days at 39℃, respectively. Placing the potatoes at 37℃ and 39℃ for 3 and 5 days did not significantly affect the germination rate or germination grade. However, with prolonged high-temperature treatment, such as after 7 days, the germination rate decreased compared to the control, and the germination grade also decreased significantly.

[0049] 6. Survival status of stem nematodes in rotten potatoes after storage The potato infected by the rot stem nematode is respectively placed at 35 DEG C, 37 DEG C, 39 DEG C for 3d, 5d, 7d, and then is transferred to a cellar (a pit), the cellar is sterilized in advance, the storage condition of the cellar is that the temperature is 4 DEG C, the humidity is 75%, the oxygen volume concentration is 4%, after 180 days of storage, the number of the rot stem nematode carried by each group of potato pieces and the growth condition of the potato pieces are counted.

[0050] The results show that the nematodes in the potato pieces treated at 35 DEG C, 37 DEG C, 39 DEG C are all dead, the number of the nematodes in 1mm*1mm unit area is 0, the rot stem nematode does not appear in the cellar stored potato pieces, which indicates that the cellar storage after the high temperature treatment of 35 DEG C, 37 DEG C, 39 DEG C can effectively kill the rot stem nematode in the potato pieces.

[0051] It should be noted that when the present application claims involve numerical ranges, both endpoints of each numerical range and any number between the two endpoints can be selected, and in order to prevent repetition, the present application describes preferred embodiments.

[0052] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0053] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A method for controlling a plant storage root-rot nematode, characterized by, The crops are first placed at a temperature of 35-41°C for 1-11 days, and then stored; The crops are potatoes or iris roots.

2. The method of claim 1, wherein, The temperature is 37-41°C, and the treatment time is 3-11 days.

3. The method of claim 1, wherein, The temperature is 37-39°C, and the treatment time is 3-5 days.

4. The method of claim 1, wherein, The storage temperature is 2-8°C.

5. The method of claim 1, wherein, The humidity during storage is 60-90%.

6. The method of claim 1, wherein, The oxygen concentration in the storage environment is 3-5%.

7. The method of claim 1, wherein, The storage is carried out in a cellar.

8. The method of claim 7, wherein, The cellar is a pit cellar or a brick cellar.

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