JPS595561B2 - Cucumber spot bacterial disease control agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel control agent that can accurately control bacterial spot disease of cucumbers.

Specifically, the present invention relates to a cucumber spot bacterial disease control agent containing kasugamycin or its salts (hereinafter abbreviated as KSM) as an active ingredient.

Traditionally, side dishes such as cucumbers, tomatoes, and eggplants were grown seasonally, but with the spread of greenhouse horticulture technology and increased demand from the general public, they are now grown year-round regardless of the season. .

In particular, since these types of vegetables require appropriate temperature, humidity, and sunshine hours other than the usual seasonal cultivation, from the point of view of cultivation management, now-us cultivation is becoming mainstream.

However, when cultivated in greenhouses under the limited artificial temperature conditions, especially under conditions of excessive humidity, seeds are susceptible to diseases and suffer extensive damage, which can easily lead to reduced yields and deterioration of quality. etc. is not desirable.

Traditionally, the main pathogenic bacteria for cucumbers, etc., include powdery mildew, late blight, scab, char blight, downy mildew, and gray mold, and many control agents have been developed and are actually effective against these diseases. Various pesticides have been used.

However, in recent years, cucumber spot bacterial disease has been rapidly replacing these diseases, which have traditionally been considered as major diseases, and is causing great damage.

Bacterial cucumber spot disease is highly contagious, spreads within a short period of time after it begins to appear in greenhouses with appropriate temperature and humidity, and is extremely difficult to control with chemicals. The outbreak of cucumber spot bacterial disease poses a major threat to future forced and semi-forced cucumber cultivation.

Under these circumstances, there are great expectations for the early development and practical application of cucumber spot bacterial disease control agents.

Bacterial cucumber spot disease is known to be transmitted mainly through infected seeds.

In particular, if the virus is carried in the seeds, it is transmitted to the cotyledons upon germination, causing damage such as large, water-soaked lesions occurring one after another, and spots on young seedlings softening and dying.

Therefore, the current method of control is to first sterilize the seeds, then spray them with chemicals early after germination, or use a combination of these methods.

Currently, mercury has been used as a disinfectant at the seed stage, although it is not sufficiently effective against bacterial bacterial spot disease of cucumbers. Due to problems, its use is currently prohibited.

In addition, in the United States, 1000 times the temperature is increased (15 to 20℃).
9 for 5 minutes, immersion in hot water at 50 to 100°C, immersion in streptomycin, etc. have been proposed, but these methods are still insufficient.

In addition, as a dispersing agent, some effect can be expected by spraying a hydration dispersible agent mainly made of basic inorganic acid steel, 4-4 lime Bordeaux liquid, Bordeaux liquid for stomai, and stomai + tetracycline liquid every 5 to 7 days. It is said that it will be done.

However, due to the high concentration of these pot agents used, they often cause damage to leafy greens, so it is necessary to lower the concentration of use, and at present, there are few products that can be expected to adequately control them. Although these drugs appear to be effective in reducing the incidence of cucumber spot bacterial disease for a short period of time immediately after spraying, they become less effective over time, so it is thought that these drugs lack long-lasting medicinal efficacy. be done.

In view of these current circumstances, the present inventors conducted various studies to develop a control agent for bacterial spot disease of cucumbers, and as a result, as mentioned above, we have found an antibiotic that is highly effective against rice blast disease of paddy rice. It has been found that by using KSM as an active ingredient, cucumber spot bacterial disease, which had been considered difficult to control, can be completely controlled.

The present invention has been made based on such completely new findings.

KSM, which is the active ingredient of the cucumber spot bacterial disease control agent according to the present invention, is a known antibiotic (see Japanese Patent Publication No. 42-6818 and Japanese Patent Publication No. 41-21757) and is specifically effective against rice blast disease at extremely low concentrations. In addition to being known to be effective against Pseudomonas aeruginosa, which is a parasitic organism that occurs in animals, the cucumber spot bacterium is said to be useful. It was not fully known what kind of effect KSM had on diseases such as disease.

The present inventors have discovered that the bacterial bacterium disease of cucumber, which has been considered difficult to control, has been shown to be fully effective against the disease.
By using KSM, which was unknown, as a seed disinfectant or as a foliar spray, we discovered that it can be extremely effective in controlling scale, making it an extremely useful agent for controlling cucumber spot bacterial disease. .

The pesticidal agent according to the present invention can be effectively used as a disinfectant at the seed stage for the control of cucumber bacterial spot disease, and as a dispersing agent as a preventive agent before the onset of the disease and a therapeutic agent after the onset of the disease.

The amount of KSM used in the present invention is usually KSM100.
~400 ppm.

Next, the control effect of the control agent of the present invention on cucumber spot bacterial disease will be explained using test examples.

Test Example 1 As a test method for preventing bacterial spot disease in cucumbers, when cucumbers (variety Natsaki Ochi No. 3) grown at a ratio of 1 plant per 12 crrL flower pot reached the 3-leaf stage, a prescribed concentration of the chemical solution was applied to 100 m F7+
The mixture was sprayed using a hisshaku-type sprayer at a rate of 3:3.

The day after the spraying, the cucumber spot was cultured in a potato semi-synthetic medium for 24 hours, and then spray-inoculated as a bacterial suspension adjusted to a bacterial pathogen concentration of 109 cells/ml, and kept in a humid room for 48 hours, then left standing in a greenhouse.

The test was conducted in triplicate in one area, and the degree of disease onset and degree of chemical damage on the 8th day after inoculation were expressed using the following indicators, and the diseased dust and control value were calculated using the missing formula.

Survey indicators Affected area (%) Coefficient AOO B 1-51 0 6-20 2 D 21-40 3 E 41-60 5 F 60 or more 8 The survey results are shown in Table 1 below.

In the table, KSM represents kasugamycin alone or hydrochloride; all concentrations are expressed as a single substance; the concentrations of basic copper chloride and cupric hydroxide (ppm) are expressed as copper; and the control drug is a commercially available Streptomycin hydrating powder (25%) was used.

The same method was used in the following test examples.

Table 1 Application amount Test chemical for control side Diseased dust
Drug harm (ppm)
(%) KSM 400 0 100 None/
/ 200 7.5
91.9 〃ll
100 15.7 83.0
〃／／ 50
25.4 72.5
〃Control A (strike 400 38.2 5
8.7 None Leptomycin) 200 57.5 37.8
Control B (base 1000 40.5 56.
2 Very small amount of brownish copper chloride) 50069.4 24.9 None 250 9 (C12,6/ Control C (Hydrohydric acid 1000 30.0 67.
5 Very small amount of visible cuprous) 50046.8 49.4 None 250 66.9 27.6 // Untreated area 92.5 0
-Test Example 2 As a test method for the cucumber spot bacterial disease treatment effect, when cucumbers (cultivar Natsaki Ochi No. 3) grown in a 12crIL flower pot per pot reached the 3-leaf stage, ■ 10' Ce11/pot per pot. ml of bacterial suspension was sprayed and collected in 100 ml/77+" portions, kept in a humid chamber for 48 hours, and then treated with 100 yrtl/7 of a drug solution of a predetermined concentration.
11: It was sprayed and left in a greenhouse.

The degree of disease onset and the degree of drug damage were investigated on the 8th day after inoculation, and displayed in the same manner as in Test Example 1.

The results are shown in Table 2 below.

Table 2 Application ratio Test chemical for control side Diseased dust
Drug damage level (ppm)
(%) KSM 400 0 100 None 300 1.6 98.3
//〃200 5.094.5
〃／／ 1'50
9.9 89.2 ///
/ 100 20.8
77.2 N//
50 39.9 56
．． 4/Application rate Morbidity Control value Phytotoxicity degree
pm) (%) Control A (St.
400 33.9 63.0 None Leptomycin) 200 60.5 33.
9 1/Control B (s ~ 1.000 60.
7 33,6 ll oxyquinoline copper) 500 85
7.1 11250 90 1.6
l/Control C (base 1000 56.
4 38.4 Leaf green yellowing copper sulfate) 500 6],, 0 Very slight brown/black 33.3 25078.9 None 13.7 Control D (base 1000 50.1 45.2 copper chloride) 500 59・834.6 250 73・619.6 Control E (Hydroxylic acid 1000 47.5
Leaf green yellowing cupric) 48.1 50056.1 None 38.7 250 76・416.5 Unsprayed area 91.5 8 trial test examples 3 ・・Cucumber spot bacterial disease control effect test in grass The test method is 1 section 5m? Ten cucumber plants at the 5-leaf stage (variety Natsuzaki Ochi No. 3) were completely planted in a field in a closed field, and the pathogenic bacteria was suspended twice at a concentration of 106 cells/mA, 7 days later and 17 days later. 100m17 of liquid
Inoculation was carried out by spraying to a target area of 1.5 m, and at the same time, diseased leaves were left in the furrows to encourage natural disease development.

After the specified concentration, apply the drug at 200 to 250 m at intervals of 10 days.
Sprayed 3 times with a shoulder sprayer to 1/i.

The investigation was conducted two weeks after the final application of the drug, and the severity of the disease was investigated using the same method as in Test Example 1 for all the drugs in every other 5 plants from each plot.

The survey results are shown in Table 3 below. Third
Table: Pest control value: 1″lI＠ Morbidity: Chemical damage level: test drug (ppm)
(%) KSM 400 0 100
None // 300
6.7 91.6 //〃200
15.8 80.2 #/
150 20.3
74.5 〃/'
100 40.4 49.3
〃Control A (Stroke 400 33.0
58.6 None Leptomycin) 200 61.3 23.
1 ll Application rate Morbidity Control value test drug
Drug damage level (ppm)
(%) Control B (Zichi 2000 21.6
72.9 Slightly brown anon) * 100039.7 50.2 None 300 69.9 12.4
/ Tough 7 to A' 800 24.6 69.2
//400 40.9 48.7
〃300 53.2 33.
3 Control D (base 1000 3
4.3 57.0 Slightly brown copper chloride) 50069.7 12.6 None 250 76.5 4.1 Control E
(Hydroxy acid 1000 48.1 39.7
//Silver copper oxide 500 55.8 30.0 〃250
78.4 1.7 //No spray area
79.8 0 -
(Note) * "Dithianon" and "Ambum" are commercially available disinfectants containing respectively.

Test Example 4 Seed disinfection effect against cucumber bacterial spot disease was tested using a suspension of pathogenic bacteria (109Cell/rrLl!) obtained by culturing at 27°C for 2 days using potato semi-synthetic medium.
Cucumber seeds (variety Natsusairichi No. 3) were added to the seeds and inoculated by vacuum injection (vacuum treatment for 1 hour).

The artificially inoculated seeds were air-dried and then stored in a refrigerator at 5°C until testing.

For disinfection treatment, 40 seeds of the above were added to each chemical solution at a predetermined concentration.
After soaking for 1 minute (liquid ratio 3:1), it was immediately inoculated onto the soil surface of a clay burn site with a diameter of 12 crfL without washing, and at 25°C.
It was placed in a glass chamber.

The number of seeds sown was 5 seeds per pot, and each district was divided into 5 pots.

In all disease outbreak investigations, germination rates and disease onset rates were investigated at the time of first leaf development.

The results are shown in Table 4 below.

Table 4 Applicable rate Incidence rate Test drug with control value
Drug damage level (ppm) (%) (
%) KSM 400 0 100 None 1/
300 5.2
94.6 ////
200 10.2 89
．． 4 u〃150 17.7
81.6 //〃100 40
．． 0 58.5 Control A (St 800 61.0 36.8 Leptomycin without) 400 87.5 9.3
/Control B (base 1000 62.3
35.4 Polymerized copper) 500 68.0 29.5 //25
0 85.5 11.4 //Control C (
Hydroxic acid 1000 69.1 28.4
Initial growth retardation cupric) 50078.8 18.3 None 250 88.2 8.6 / Untreated area 96.5 0
First, some examples of the present invention will be shown, but the present invention is not limited to the following examples.

Note that the middle part of the example indicates parts by weight.

Example 1 (Liquid) Kasugamycin/HCl 2 parts, polyoxyethylene alkylaryl ether 5 parts, methanol 5 parts, and water 8 parts
Mix 8 parts uniformly to form a liquid.

Example 2 (Wettable powder) A wettable powder is prepared by uniformly mixing 2 parts of kasugamycin/HCI, 3 parts of lauryl sulfate, 2 parts of ligninsulfonic acid sodium salt, and 93 parts of clay.

Claims (1)

[Claims] 1. A cucumber spot bacterial disease control agent characterized by containing kasugamycin or its salts as an active ingredient.