JP6590727B2 - How to protect against plant diseases - Google Patents

Description

  The present invention relates to a method for protecting plant diseases.

In the agricultural field, maintaining the soil of farmland in a healthy manner is important for obtaining healthy agricultural products and reducing production costs. In order to maintain a healthy soil, methods such as avoiding continuous cropping and thorough rotation, mixing crops with cover crops, adding organic matter, and minimizing tillage are the mainstream methods.
On the other hand, in recent years, techniques for cultivating and planting green manure have been developed (Non-Patent Documents 1 and 2). Conventionally, green manure was cultivated in a field during the fallow period, and the purpose was to supply organic matter containing organic nitrogen in the field by plowing. However, in recent years, it has also been used as a measure against diseases and pests of various crops. In particular, it has been clarified that when specific green manure is cultivated and plowed in, the occurrence of the target soil disease can be reduced or suppressed. For example, it has been shown that when potatoes are cultivated after planting Sudangrass or buckwheat as green manure, the occurrence of Verticillium disease is reduced and the sales increase (Non-patent Documents 3 and 4).

  However, among soil diseases, there are few green manures that can suppress the occurrence of diseases of Rhizoctonia spp., Particularly Rhizoctonia solani. Rhizoctonia spp. Are recognized as harmful bacteria that invade not only vegetables but also common crops, flowers, grass and timber. In addition, there are many strains of pathogenic bacteria themselves, and the types and symptoms of the crops that are damaged due to these strains are complicated. In general, synthetic antibacterial agents (pesticides) are used to protect against Rhizoctonia spp. However, although the safety of chemically synthesized pesticides has been well examined, there is still a strong suspicion among consumers, and organic agricultural products and reduced agricultural chemicals are nurtured. In view of this point, a method for reducing plant diseases that does not use chemically synthesized pesticides is desired.

  Patent Document 1 describes a method for protecting Rhizoctonia solani using a microorganism belonging to the genus Bacillus. Patent Document 2 proposes a method of protecting with mucor racemosus having antagonistic properties against Rhizoctonia solani. Patent Document 3 describes that compost obtained by cultivating Himetsubuhi Toyotake GM-21 strain (NITE BP-37) in compost has a protective effect of Rhizoctonia solani. There are many proposals for such a technique called microbial pesticide, but it has not yet been put to practical use.

Although the application of the green manure described above is being studied, few are available. One reason for this is that Rhizoctonia solani is polycynic and may proliferate by infecting crops grown as green manure.
Among the Rhizoctonia species, Rhizoctonia solani is further classified into mycelium fusion groups and culture types, among which the classification groups such as AG2-2IIIB and AG2-2IV are seriously damaged to root vegetables and potatoes by rooting and withering. Effect. On the other hand, when pesticides are used, there is a problem that enormous costs are imposed, and a disease reduction method using green manure cultivation has been desired. In addition, crops with high commercial value such as Chinese yam and yam did not cause damage such as rooting, but the surface was deformed such as spots and knots, resulting in significant damage to the commercial value.

  Under such circumstances, some cultivation producers of Tohoku region have a cultivation method in which clover and grass are mixed in such a proportion that clover dominates, and then cultivated after one year. In other words, it had a certain disease control effect against Rhizoctonia solani. In addition, some of the potato cultivation producers in Abuta-gun, Hokkaido, cultivated green manure mainly from vetch, and obtained a certain suppression effect. However, these legume-based green manures have insufficient effects, and a method that can provide more reliable effects has been desired.

JP 2004-215567 A JP-A-10-150978 International Publication No. 2008/149846

Larkin 2015. Soil health paradigms and implications for disease management. Annu. Rev. Phytopathol. 53: 199-221. Takeshi Hashizume 2014.Reading book with green manure crops. Davis et al. 1996. Effects of green manures on Verticillium wilt of potato. Phytopathol. 86: 444-453. Wiggins and Kinkel 2004. Green manures and crop sequences influence potato diseases and pathogen inhibitory activity of indigenous Streptomycetes. Phytopathol. 95: 178-185.

  An object of the present invention is to provide a method for preventing the occurrence of disease of Rhizoctonia solani using green manure.

  As a result of diligent research to solve the above-mentioned problems, the present inventors have cultivated orchard grass (Dactylis glomerata) as a green manure crop and planted it, followed by Avena strigosa. After cultivating and then planting this as green manure, it was discovered that cultivating the target crop can significantly prevent the occurrence of diseases caused by Rhizoctonia solani, making the present invention.

The present invention has the following configuration.
(1) It is characterized by cultivating orchard grass (Dactylis glomerata) before planting and then planting it as green manure followed by cultivating Avena strigosa and then further planting. A method for protecting plant diseases caused by Rhizoctonia solani.
(2) When cultivating orchardgrass, the seeds of plants belonging to the genus Trifolium per 1 part by weight of orchardgrass seeds are sown at 0.25 parts by weight or less at the time of sowing. How to protect against plant diseases.
(3) The method for protecting plant diseases according to (2), wherein orchardgrass and trifolium plants are grown so that orchardgrass grows as a dominant species.
(4) The plant disease protection method according to (2) or (3), wherein the plant belonging to the genus Trifolium is Trifolium pratense.
(5) The crops are Chinese yam, yam, carrot, burdock, sugar beet, taro, potato, rice, soybean, red top, bentgrass, aster, rush, iris, impatiens, peas, colours, yellow berries, yellow berries, chrysanthemum, sandersonia, The plant disease according to any one of (1) to (4), which is any one selected from Shibazakura, tulip, rose, pinpinela, broccoli, safflower, honey bee, leather fan, corn, eggplant, spinach, pepper, pepper Defense method.
(6) Plant diseases include potato or yam root rot, carrot root rot, burdock black rot, sugar beet root rot, taro stalk rot, potato scab, rice brown blight, soybean rhizoctonia root rot, Red Top Leaf Rot, Bentgrass Leaf Rot, Aster Rhizoctonia Blight, Igusa Blight, Iris Blight, Impatiens Blight, Pea Stem, Color Strain, Oyster Stem, Kyokyo Orchid blight, chrysanthemum blight, sandersonia blight, shibazakura rot, tulip skin rot, rose seedling blight, pinpinella stem rot, broccoli seed blight, safflower blight, honey bee Any of (1) to (5), which is one of the following: Blight disease, Leather fan leaf rot, Corn root rot, Eggplant seed blight, Spinach strain rot, Pepper seed blight, Pepper seed blight Either And methods of preventing plant diseases according to.
(7) The method for protecting against plant diseases according to any one of (1) to (6), wherein Rhizoctonia solani is Rhizoctonia solani AG2-2IIIB and / or AG2-2IV.

  By implementing the present invention, various diseases of crops derived from Rhizoctonia solani can be protected. Moreover, since the method of the present invention does not use agricultural chemicals, it is safe without affecting crops. In addition, the low cost increases agricultural profits. In addition, the effect of green manure improves soil and promotes crop growth.

It is drawing which shows the damage evaluation standard of Chinese yam root rot. It is an image which shows the growth condition of the plant after overwintering in O ward. It is an image which shows the growth condition of the plant after overwintering in C ward. It is an image which shows the growth condition of the plant after overwintering in R ward. It is an image which shows the growth condition of the plant after overwintering in M ward.

The method of the present invention and the plant for green manure used in the method will be described.
<Orchardgrass cultivation and green manure>
Orchard grass (English name: Orchard grass, scientific name: Dactylis glomerata) is a perennial of the genus Camellia, and is also distributed in the English name Orchard Grass. Orchardgrass varieties include Bacchus (Snow Brand Seed Co., Ltd.), Harune Midori (National Institute of Agricultural and Food Research, Hokkaido National Agricultural Research Center), Haljiman (National Institute of Agriculture and Food Industrial Technology) Organizations include the Hokkaido Agricultural Research Center), Toyomidori (National Institute for Agricultural and Food Research, Hokkaido Agricultural Research Center), and Pikal (Hokuren). Moreover, in order to improve environmental adaptability, a plurality of types may be mixed and used.
Orchardgrass is first cultivated in a field contaminated with Rhizoctonia solani. The weight of seeds to be sown during cultivation is 2 to 6 kg per 10a, preferably 3 to 4 kg.
The sowing time is usually from late summer to autumn, but the sowing time can be changed depending on the target crop. In sowing, plants belonging to the genus Trifolium can be mixed. Trifolium plants are a group of plants commonly referred to as “clover”, and the Japanese name is “Shajixou”. The purpose of sowing a small amount of Trifolium plants is to improve the water permeability by destroying the cultivator through the growth of its straight roots or to reduce fertilizer by fixing nitrogen in the air. When co-planting trifolium plants, they are cultivated at such a ratio that orchardgrass grows as the dominant species in the field. For this reason, seeds of orchardgrass and trifolium genus plants are sown so as to have a ratio of 0.25 parts by weight or less of trifolium seeds per 1 part by weight of orchardgrass seeds. Trifolium seeds include red clover (Trifolium pratense, white clover), white clover (Trifolium repens), crimson clover (Trifolium incarnatum), alcyclover (Trifolium hybridum), etc. Red clover is particularly preferable because it does not hinder the growth of orchardgrass. As for the red clover varieties, Harukaze (Yukiinase Seedling Co., Ltd.), Ares (Yukiinase Seedling Seed Co., Ltd.), Makimidori (Yukiinase Seedling Seedling Co., Ltd.), Natsyu (National Institute of Agriculture and Food Technology) Hokkaido Agricultural Research Center ), Ryokuyu (Hokkaido National Agricultural Research Center, National Institute for Agricultural and Food Research), Melby (Hokuren).
White clover varieties include Rivendel (Snow Brand Seed Co., Ltd.), Rumenai (Snow Brand Seed Seed Co., Ltd.), Fia (Snow Brand Seed Seed Co., Ltd.), Riesling (Hokuren), Makibashiro (Hokuren), Sonya (Hokuren), Tahora (Hokuren) ) And the like.
Crimson clover varieties (Snow Brand Seedling Co., Ltd.), ordinary species (Takii Seedling Co., Ltd.), etc. are listed.
Alcyc clover varieties include ordinary varieties (Hokuren).
These clovers may be used in a mixture of a plurality of types and a plurality of types in order to enhance environmental adaptability.
Moreover, in order to secure biomass before overwintering, you may mix-see oat seeds. There are no particular restrictions on the variety of oats, but upright oats are preferred because they do not hinder the growth of orchardgrass. Examples of upright oats include varieties Tochiyuka (Snow Brand Seed Co., Ltd.), Swan (Hokuren), Stand Oats (Kaneko Seed Seed Co., Ltd.) and the like.
Moreover, when orchardgrass is cultivated, it is needless to say that plants other than the above can be mixed and seeded within a range that does not hinder the dominance of orchardgrass after wintering.
The seeding amount of the oat is 0.1 to 5 kg, preferably 0.5 to 3 kg. Especially in snowy areas, it can cause snow rot, so mixed soaking of 3 kg or more is not preferable.

Apply original fertilizer as needed when sowing. The amount of fertilizer applied is preferably 0 to 10 kg, 0 to 25 kg, and 0 to 15 kg per 10a as nitrogen, phosphate, and potassium components, and more preferably 4 to 6 kg, 4 to 15 kg, and 4 to 9 kg, respectively.
The sowing time is not particularly limited as long as the amount of growth before wintering can be secured, but it is desirable to sow at least 3 months before the expected snowfall date in a snowy area. Specifically, April to September is preferable, and May to June or August to September is more preferable.
According to the cultivation of this method, orchardgrass usually dominates after overwintering, but if for some reason the growth of co-planted plants such as clover becomes more vigorous than orchardgrass, Orchardgrass can be predominated by appropriately treating herbicides for grass. Specific examples of the herbicide include MDBA (dicamba) agent and thifensulfuron methyl agent.
The seeded orchard grass is sown into the soil after growth. At that time, if the orchardgrass grows well, a part of the orchardgrass can be cut and used as pasture.
Although there is no restriction | limiting in particular in the pouring method, In order to accelerate | stimulate the maturity of the above-ground part, it is desirable to shred the above-ground part before pouring. Needless to say, agricultural machines such as choppers and flermore can be used. There is no particular limitation on the method of mixing the soil after the above-ground shredding, but it is desirable that the tillage depth be 20 cm or less so as not to disturb the organic matter such as the root system in the soil excessively. As an agricultural machine for this work, it is preferable to use a rotary, a power harrow, a disk harrow or the like.
There is no particular limitation on the sowing time as long as the growth of orchardgrass can be secured and the standard growth of Avena strigoosa to be cultivated thereafter can be secured. When overwintering, June to September is preferable, and July to August is more preferable.

<Avena Strigotha cultivation and green manure seeding>
After orchardgrass sowing, organic matter in the topsoil is decomposed and seeded with Avena Strigotha. There is no particular limitation on the period from seeding of orchardgrass to sowing of Avena strigoosa, but it is desirable to keep it for 2 weeks or more.
Avena strigoosa (English name: Lopsided Oat, scientific name: Avena strigosa) is a plant belonging to the genus Oataceae and is cultivated as grass.
As the cultivar of Avena strigoosa, those having a high effect of controlling the root-knot nematode are preferable. Specific examples include Heiotsu (Snow Brand Seedling Co., Ltd.), Prelatex (Hokuren), Sire (Hokuren), and the like, but Heitatsu is preferable from the viewpoint of the effect of controlling the root-knot nematode and biomass production. The seeding amount is 8 to 20 kg per 10a, preferably 10 to 15 kg, in order to enhance the effect of controlling the root-knot nematode. It should be noted that when weeds are mixed, the root-knot nematode grows at its roots, reducing the effect of the present invention of Avena strigoosa and the disease control effect. It is desirable to increase the amount to 15-20 kg per 10a.

The fertilization amount is not particularly limited as long as the standard growth of Avena strigoosa can be secured. The amount of nitrogen component is 0-7 kg per 10a, preferably 4-5 kg.
It is preferable to crush the surface soil so that the tillage depth is 20 cm or less immediately before sowing, and to reduce the pressure after sowing. Although sowing is sufficient as the seeding method, a drill seeder can be used as long as the intercostal space can be set to 20 cm or less.
After cultivating Avena strigoosa, if it is cultivated for 60 days or more, a sufficient suppression effect on the northern root nematode is obtained. The method of engraving is the same as that of orchard glass.
In addition, organic fertilizer and organic matter can be applied in order to further improve the physical and microbial environment in the soil during the cultivation and plowing of the green manure. Specific examples include soybean meal, wheat bran, rapeseed meal, and okara.
Moreover, when cultivating the target crop, an agrochemical can also be used in order to further enhance the plant disease suppressing action. Examples of agricultural chemicals used include carbam sodium salt, chlorpicrin agent, dazomet agent, thiuram agent, benomyl agent, pencyclon agent, tolclophosmethyl agent, azoxystrobin agent, furametopill agent, flutolanil agent, mepronil agent and the like.

<Cultivation of crops>
After planting Avena Strigoosa, the organic matter in the topsoil is decomposed, so that crops for commercial cultivation can be seeded or seedlings / vegetative propagation bodies (such as seed potatoes) can be planted. Cultivation of a crop may be performed according to a standard method for each crop. It is desirable that sowing or planting be carried out for at least 2 weeks after invading Avena Strigotha.

The method of the present invention can be applied in a field where damage of Rhizoctonia solani AG2-2IIIB and / or AG2-2IV occurs, a field with a history of occurrence in the past, or a field where occurrence is expected. Specific examples of diseases include Chinese yam or yam root rot, carrot root rot, burdock black rot, sugar beet root rot, taro stem rot, potato lumbar symptom, rice brown blight, soybean rhizobonia root rot , Red top leaf rot, bentgrass leaf rot, aster rezoctonia blight, rush blight, iridium blight, impatiens blight, pea stem rot, color rot, color stalk rot, Kyokyokuran rot, Chrysanthemum wilt, Sandersonia wilt, Shibazakura strain rot, Tulip skin rot, Rose seed rot, Pinpinella stalk rot, Broccoli seed rot, Safflower wilt, Examples include honey bee blight, leather fan leaf rot, maize root rot, eggplant seed blight, spinach strain rot, capsicum seed blight, and bell pepper seed blight.
Any plant or variety that can serve as a host for Rhizoctonia solani AG2-2IIIB and / or AG2-2IV can be used as a target crop of the method of the present invention. Chinese yam, yam, carrot, burdock, sugar beet, taro, potato, rice, soybean, red top, bentgrass, aster, rush, iris, impatiens, peas, colours, yellow berries, yellow berries, chrysanthemum, sandersonia, white cherry, tulip, rose , Pinpinella, broccoli, safflower, honey bee, leather fan, corn, eggplant, spinach, chili pepper, and pepper.
Furthermore, a kit combining the seeds for green manure suitable for protecting the plant disease by carrying out the method of the present invention can be provided as a kit for protecting the plant disease.

The effects of the present invention will be described more specifically with reference to test examples and examples.
Test Example 1 <Confirmation of potato root rot suppression effect by pot test>
(1) Test method Soil was collected from a field of occurrence of root rot of Chinese yam in Obihiro City, Hokkaido, and filled into a 1 / 5000a Wagner pot.
A. The first green manure cultivation In September, Orchardgrass variety Bacchus (Snow Brand Seed Co., Ltd.), red clover variety Harukaze (Snow Brand Seed Co. Ltd.), white clover variety Rivendel (Snow Brand Seed Co. Ltd.), Crimson Clover Variety (Snow Brand) 1 g of each seedling (seed) was seeded.
Similarly, a pot filled with soil was installed as an untreated section. Cultivation was performed in a greenhouse set at a minimum temperature of 3 ° C., and irrigation and fertilization were performed as appropriate. The above-ground part of the plant that had been cultivated in June of the following year was cut and shredded to 3 cm or less with scissors and mixed well with the soil taken out from the pot. The mixed soil was put in a separate bucket and allowed to stand in a greenhouse to promote green manure.

B. Second Green Manure Cultivation Then, the soil was refilled in a 1 / 5000a Wagner pot, and in July, 3 g of Avena Strigoza variety Heiotsu was sown and cultivated in the same manner as described above. In September, the above-ground part was cut and mixed with soil in the same manner as above. The mixed soil was placed in a polyethylene bag and stored at room temperature.

C. Cultivation and Evaluation In April of the following year, each soil was refilled into 1 / 5000a Wagner pots, and three potato mussels were planted per pot. At that time, a part of the untreated soil was autoclaved at 121 ° C. for 15 minutes to obtain a sterilized soil section. After that, it was cultivated in a greenhouse for 90 days in the same manner as described above, and the weight and disease severity of the rooted roots were measured in the 1995 Tohoku Agricultural Research Result Information Prediction of Occurrence of Chinese Root Rot. The damage was evaluated according to the damage survey standard (Fig. 1).

(2) Results The used green manure plants and the evaluation results are shown in Table 1 below.

No disease was observed in sterile soil. On the other hand, the occurrence of disease with an index of about 3 was observed in the untreated area. In addition, the first treatment showed a significant reduction in the severity of the disease in the Orchardgrass area. On the other hand, in the red clover, white clover, and crimson clover areas, the severity of the disease was not reduced, and the results were similar to those in the untreated area.
The combination of Orchardgrass and Avena Strigoosa was able to protect Chinese root rot caused by Rhizoctonia solani.

Test Example 2 <Verification of burdock black bruise suppression effect by pot test>
(1) Test method A.1. 1st and 2nd green manure cultivation Soil collected from burdock black bruise field in Obihiro city, Hokkaido, filled into 1 / 5000a Wagner pot, and 1g of Orchardgrass variety Bacchus (Snow Brand Seed Seed Co., Ltd.) Sowing. The others were cultivated, ground part shredded, mixed with soil, avena / strigotha grown, grounded shredded, mixed with soil in the same manner as in Test Example 1.

B. Cultivation and evaluation In April of the following year, three burdock varieties Yanagawa ideal (Takii Seed Co., Ltd.) were sown per pot. At that time, a part of the untreated soil was autoclaved at 121 ° C. for 15 minutes to obtain a sterilized soil section. Thereafter, it was cultivated in a greenhouse for 2 months in the same manner as described above, roots were dug up, and after washing, root rot symptoms at the root were investigated according to the following indices to calculate an average disease index.
Index 0: No blackening of roots observed 1: Blackening of less than 10% of roots 2: Blackening of 10% to less than 50% of roots 3: Blackening of 50% or more of roots

(2) Results Table 2 shows the evaluation results.

  In the sterilized soil, no disease was observed, but in the untreated plot, blackening was observed in more than 50% of the roots. On the other hand, in the section where the orchardgrass and Avena strigoosa of the present invention were cultivated, the root rot symptom of the root was 10% to less than 50%, and the reduction of the blackening symptom was recognized.

Test Example 3. <Confirmation of carrot root rot suppression effect by pot test>
(1) Test method A.1. 1st and 2nd green manure cultivation Soil was collected from the carrot root rot outbreak field in Toyako-cho, Abuta-gun, Hokkaido, filled into 1 / 5000a Wagner pot, and orchardgrass varieties Bacchus (Snow Brand Seed Co., Ltd.) ) Was seeded. The others were cultivated, ground part shredded, mixed with soil, avena / strigotha grown, grounded shredded, mixed with soil in the same manner as in Test Example 1.

B. Cultivation and evaluation In April of the following year, 3 seeds of carrot cultivar Fressy (Snow Brand Seedling) were sown per pot. At that time, a part of the untreated soil was autoclaved at 121 ° C. for 15 minutes to obtain a sterilized soil section. Thereafter, the plant was cultivated in a greenhouse for 2 months in the same manner as in Test 2 described above, roots were dug up, and after washing, root rot symptoms at the root were investigated according to the following indices to calculate an average disease index.
Index 0: No blackening of roots observed 1: Blackening of less than 10% of roots 2: Blackening of 10% to less than 50% of roots 3: Blackening of 50% or more of roots

(2) Results Table 3 shows the evaluation results.

  In the sterilized soil, no disease was observed, but in the untreated area, blackening symptoms were observed in more than 50% of the roots. On the other hand, in the area where the orchardgrass and Avena strigoosa of the present invention were cultivated, the reduction of blackening symptoms was recognized as 10% to less than 50%.

<Examples and comparative examples by field cultivation>
Since good results were obtained in Test Examples 1 to 3, cultivation in a field was performed, and the method of the present invention was compared with a comparative example.
(1) Cultivation example A. 1st field cultivation of green manure N: P: K = 5kg: 5kg: 5kg fertilized in the amount of ingredients as raw manure in Nagano root rot occurrence field in Obihiro City, Hokkaido, O, M, R, C, untreated 5 sections The green manure seeds mixed at the ratio shown in Table 4 below were mixed and seeded on August 14th.

M ward is the proportion of green manure based on the cultivation method implemented by the yam producers in the Tohoku region. The name of each green manure plant is the oat variety Tochiyuka (Snow Brand Seed Co., Ltd.), Orchardgrass variety Bacchus (Snow Brand Seed Co., Ltd.), red clover variety Harukaze (Snow Brand Seed Co., Ltd.), Crimson Clover Variety None (Snow Brand Seed Seed Co., Ltd.) and rye variety R-007 (Snow Brand Seed Seed Co., Ltd.) were used.
During the cultivation of green manure, the cultivated plants were dominant in the area where the green manure seeds were sown, but weeds were appropriately removed because weeds were generated in the untreated area.
Oats can't overwinter, so they die during the winter, and in the next spring, Orchardgrass dominates in O (Orchardgrass), and red clover dominates in M (Mix), while small amounts of Orchardgrass and Crimson Clover. Coexisted, rye was dominant in R (rye), and red clover was dominant in C (clover). The state is shown in FIGS.

After that, since the grain of rye was growing in the R district, the ground part was shredded with a chopper on June 26 and plowed by rotary tilling at a depth of 15 cm. In O, M and C, the ground part was shredded with a chopper on August 10 and similarly plowed and plowed.
Next, 15 kg / 10a of Avena strigoosa variety Heiotsu was sown on half the area of each treatment section. In addition, relay cultivation of Avena and Strigosa is not carried out by the cultivation method implemented by Chinese yam producers in Tohoku region. The plant was dominant in the Avena-Strigousa seeding group, but weeds were generated in the non-seeding group, so weeded by surface agitation with a rotary at a depth of about 5 cm. The Avena Strigotha sowing area was chopped on October 12 with a chopper and plowed by rotary tilling at a depth of 15 cm.

These test plots were cultivated by planting Chinese yams as usual on May 20 of the following year.
On October 26th, excavation of rooted roots was conducted (2 iterations).
The weight of all root support bodies in each test section was measured, and the number ratio within the standard was calculated with 200 g or more within the standard. As a result, the O, M, and C wards that were cultivated with green manure compared to the untreated tracts that were not cultivated with green manure were subject to Abena / Strigotha cultivation and the number ratio within the standard increased.
Nineteen rooted roots showing average growth were selected from each test section, and the soil on the surface of the rooted roots was washed away with tap water, and the degree of damage was evaluated based on the root rot evaluation criteria shown in FIG. The results are shown in Table 5 below.

As a result, in Examples 1, 2, and 3, the disease strain rate decreased compared to no treatment. In particular, in Example 3, the disease-causing strain rate was remarkably reduced, and the in-standard number ratio was remarkably increased. Examples 1 (R-ku), 2 (M-ku), and 3 (O-ku) that cultivated Avena strigoosa were root rot as compared with Comparative Examples 4, 3, and 2 that did not cultivate each Avena strigoosa. The pathogenic strain rate of was clearly low.
On the other hand, in Comparative Example 5 which is a C ward, the ratio of the number in the standard is low, and in Comparative Example 6, the disease-causing strain rate is high. It was speculated that this was because orchardgrass was not cultivated in the first green manure cultivation. Example 3 was considered to be an effect due to the fact that orchardgrass predominated after wintering, although red clover grew in the first green manure cultivation.

Claims (7)

  Rhizoctonia solani, characterized by cultivating orchard grass (Dactylis glomerata) before planting and then planting it as green manure, followed by cultivating Avena strigosa. (Rhizoctonia solani) is a method to protect against plant diseases caused by causative bacteria.   The plant disease according to claim 1, wherein the seeds of plants belonging to the genus Trifolium are mixed and cultivated at 0.25 parts by weight or less per 1 part by weight of orchardgrass seeds when cultivated orchardgrass. Defense method.   The method for protecting plant diseases according to claim 2, wherein cultivation of orchardgrass and trifolium plants is such that orchardgrass grows as a dominant species.   The plant disease protection method according to claim 2 or 3, wherein the plant belonging to the genus Trifolium is red clover (Trifolium pratense).   Crop is Chinese yam, yam, carrot, burdock, sugar beet, taro, potato, rice, soybean, red top, bentgrass, aster, rush, iris, impatiens, peas, colour, yellow-bellied, yellow-bellied, chrysanthemum, sandersonia, white cherry, tulip The method for protecting against plant diseases according to any one of claims 1 to 4, wherein the method is any one selected from the group consisting of rose, pinpinella, broccoli, safflower, honeybee, leather fan, corn, eggplant, spinach, pepper, and bell pepper.   Plant diseases are root rot of yam or yam, carrot root rot, burdock black rot, sugar beet root rot, taro stalk rot, potato loin symptom, rice brown blight, soybean rhizoctonia root rot, red top leaf Rot, bentgrass leaf rot, aster lysoctonia blight, rush blight, iridium blight, impatiens blight, pea stem rot, color strain rot, yellow stalk rot, yellow bryo Disease, chrysanthemum blight, sandersonia blight, shibazakura strain rot, tulip skin rot, rose seedling blight, pinpinella stem rot, broccoli seed blight, safflower blight, honey bee blight 6, leather fan leaf rot, maize root rot, eggplant seedling blight, spinach strain rot, capsicum seed blight, bell pepper seed blight And methods of preventing plant diseases.   The method for protecting against plant diseases according to any one of claims 1 to 6, wherein Rhizoctonia solani is Rhizoctonia solani AG2-2IIIB and / or AG2-2IV.