阅读说明：本技术 防治温室作物霜霉病的方法 (Method for preventing and controlling downy mildew of greenhouse crops ) 是由 张修国 王玉姣 孟哲 于 2021-07-29 设计创作，主要内容包括：本发明属于温室作物栽培技术领域,涉及一种防治温室作物霜霉病的方法,包括在温室作物栽培间行覆施颖壳的步骤,本发明还涉及颖壳在防治温室作物霜霉病中的用途,以及颖壳在制备用于防治温室作物霜霉病的组合物中的用途。本发明的方法有效控制了温室作物霜霉病的发生与危害,同时充分利用了农作物废弃物,减少了化学农药用量,绿色环保,技术成本低、操作简便、使用性强,效益显著。(The invention belongs to the technical field of greenhouse crop cultivation, and relates to a method for preventing and treating downy mildew of greenhouse crops. The method effectively controls the occurrence and harm of downy mildew of greenhouse crops, fully utilizes crop wastes, reduces the dosage of chemical pesticides, is green and environment-friendly, and has the advantages of low technical cost, simple and convenient operation, strong usability and obvious benefit.)

1. A method for controlling downy mildew of greenhouse crops, comprising the steps of: glumes are spread in the greenhouse crop cultivation room.

2. Method for controlling downy mildew of greenhouse crops, according to claim 1, characterized in that glumes are applied during the growth period of the greenhouse crop, preferably during the colony period or seedling period.

3. The method for controlling downy mildew of greenhouse crops, according to claim 1, wherein the glumes are glumes obtained after being subjected to film-sealing high-temperature natural fermentation for about 20-30 days.

4. The method for controlling downy mildew of greenhouse crops, as claimed in claim 3, wherein said glumes are applied in an amount of about 1.0kg/m, based on the area of said greenhouse crop cultivation room row²To 5.0kg/m²Preferably about 3.5kg/m²。

5. Method for controlling downy mildew of greenhouse crops, according to claim 1 or 2, wherein the glumes are grass glumes, such as rice hulls, barley hulls, oat hulls, wheat hulls, millet hulls, preferably rice hulls.

6. A method for controlling downy mildew of greenhouse crops, as claimed in claim 1, wherein said downy mildew is grape downy mildew, cucumber downy mildew, tomato downy mildew, asparagus lettuce downy mildew, watermelon downy mildew, cabbage downy mildew, soybean downy mildew, preferably cucumber downy mildew.

7. Use of glumes for controlling downy mildew of greenhouse crops.

8. The use according to claim 7, wherein the glumes are glumes after being subjected to membrane-sealing high-temperature natural fermentation for about 20-30 days.

9. Use according to claim 7, characterized in that the glume is a gramineous glume, such as rice husk, barley husk, oat husk, wheat husk, millet husk, preferably rice husk.

10. Use of glumes for the preparation of a composition for controlling downy mildew of greenhouse crops.

Technical Field

The invention belongs to the technical field of greenhouse crop cultivation, and particularly relates to a method for preventing and controlling downy mildew of greenhouse crops.

Background

Downy mildew, commonly known as black hair disease, is an important disease in the growth of melon vegetables. The main damage to the leaves occurs, the leaves appear water-soaked yellow spots at the early stage of disease attack, and the spots are gradually enlarged and then are limited by veins to form yellowish-brown irregular polygonal spots. Under humid conditions, a dark gray mold layer grows on the back of the lesion. The disease generally develops from lower leaves to upper leaves, and when the disease is serious, the disease spots are connected into pieces, so that the leaves become yellow and dry and are easy to break, and the plants in a diseased field become yellow and withered. The downy mildew pathogenic bacteria are obligate parasitic bacteria of flagellata and Pseudoperonospora cucumber downy mildew (Pseudoperonospora cubensis), and the asexual zoospores, cyst stalks and mycelia are mainly used for infecting and damaging crop leaves of grapes, melons, cucumbers and the like by means of air flow and rainwater transmission. Downy mildew is a high-humidity low-temperature disease, the relative humidity of the protected environment is more than 80%, the temperature is about 23 ℃, downy mildew is suitable for occurrence and prevalence, the downy mildew is fast in occurrence, serious in harm and difficult to prevent and treat, the leaves of the whole plant can die within two weeks of occurrence, the yield is reduced by 20% -50%, and the yield and the quality of the plant are seriously affected.

Because the downy mildew resistant varieties in the planting process of crops such as cucumbers, melons, grapes and the like are seriously lacking and insufficient, the temperature in spring and autumn of a protected land in northern China is low, the relative humidity is high, the downy mildew is favorably generated and popularized, and new pathogenic microspecies are continuously and alternately generated and popularized, so that the establishment of a high-efficiency green downy mildew prevention technology is difficult. For a long time, downy mildew still mainly depends on chemical prevention and treatment technical measures, the problems of drug resistance and phytotoxicity residue are increasingly prominent due to single use and frequent overdose, and the establishment of a protected downy mildew pesticide for replacing a green prevention and control technology is urgently needed, so that the pesticide consumption is reduced, and the yield and the quality of green pollution-free crops are remarkably increased.

In recent years, the application and popularization of a novel sunlight greenhouse cultivation technology, a novel ecological film mulching cultivation technology, a novel wood-dipping grafting cultivation technology and a straw bioreactor cultivation technology effectively reduce the occurrence and harm of downy mildew of greenhouse crops, but in the early years of heavy rainfall in late spring and autumn, the relative humidity of the ecological environment for cultivating protected crops is often over 80%, and the temperature is reduced to below 23 ℃, so that the downy mildew of protected crops is easily caused to seriously occur and prevail. Therefore, aiming at the characteristic that the downy mildew of the greenhouse crops is a high-humidity low-temperature disease, a novel green prevention and control method for the downy mildew of the greenhouse crops is urgently needed to be established, so that the efficient green prevention and control of the downy mildew of the greenhouse crops are realized, the using amount of chemical pesticides is reduced, the yield and the quality of the greenhouse crops are obviously improved, and green and healthy food is provided for people.

Disclosure of Invention

In view of the above, the present invention aims to provide a method for controlling downy mildew of greenhouse crops, which reduces the dosage of pesticides and provides green and healthy crops for people.

The object of the present invention and the solution of the technical problem can be achieved by the following technical solutions.

In a first aspect of the present invention, there is provided a method of controlling downy mildew of a greenhouse crop, comprising the steps of: glumes are spread in the greenhouse crop cultivation room.

In an embodiment of the first aspect of the invention, glumes are applied during the growth phase of the greenhouse crop, preferably during the plantlet or seedling phase.

In an embodiment of the first aspect of the present invention, the glumes are glumes sealed with a film after a high-temperature natural fermentation treatment for about 20 to 30 days.

In an embodiment of the first aspect of the invention, the glumes are present in an amount of about 1.0kg/m based on the area of the row of the greenhouse crop cultivation room²To 5.0kg/m²Preferably about 3.5kg/m²。

In an embodiment of the first aspect of the invention, the glume is a gramineous glume, such as rice hull, barley hull, oat hull, wheat hull, millet hull. In a preferred embodiment of the invention, the glumes are rice hulls. In a further preferred embodiment of the invention, the glumes are rice hulls covered with a film and sealed after a high temperature natural fermentation treatment for about 20-30 days.

In a second aspect of the invention, the invention provides the use of glumes for the control of downy mildew of greenhouse crops.

In an embodiment of the second aspect of the invention, the glume is a gramineous glume, such as rice hull, barley hull, oat hull, wheat hull, millet hull.

In an embodiment of the second aspect of the present invention, the glumes are glumes sealed with a film after a high-temperature natural fermentation treatment for about 20 to 30 days.

In a preferred embodiment of the second aspect of the invention, the glumes are rice hulls covered with a film and sealed after a high temperature natural fermentation treatment for about 20 to 30 days.

In a third aspect of the invention, the invention provides the use of glumes in the preparation of a composition for controlling downy mildew of greenhouse crops.

In an embodiment of the present invention, the downy mildew may be, for example, grape downy mildew, cucumber downy mildew, tomato downy mildew, asparagus lettuce downy mildew, watermelon downy mildew, cabbage downy mildew, soybean downy mildew. In a preferred embodiment of the invention, the downy mildew is cucumber downy mildew.

Compared with the prior art, the invention has obvious beneficial effects. The glumes are residual materials of crops with moisture absorption and heat preservation performances, and the glumes, particularly rice husks, are applied among greenhouse crop cultivation rows, so that the generation and the damage of the downy mildew of the greenhouse crops are effectively controlled, the using amount of chemical pesticides is reduced, and the economic, social and ecological benefits of greenhouse crop cultivation are obviously improved. In addition, the invention fully utilizes the crop wastes, has low technical cost, environmental protection, simple and convenient operation, strong usability and obvious benefit, is a novel cultivation technology for crops in northern protected areas, and is convenient for large-area popularization and application.

Drawings

FIG. 1 shows a process of applying rice hulls to greenhouse crops to absorb moisture in air.

FIG. 2. greenhouse cucumber intercropping with different rice hull amounts, T1:15kg rice hull treatment, T2: 20kg rice hull treatment, T3: 25kg rice hull treatment, WT: a cucumber shed without rice hull treatment.

FIG. 3 shows the change of the downy mildew disease index of greenhouse cucumbers treated by different rice hull amounts, wherein T1 is treated by 15kg of rice hulls, and T2 is: 20kg rice hull treatment, T3: 25kg rice hull treatment, WT: no rice hull treatment is performed.

FIG. 4 comparison of the effect of different rice hull amounts on Peronospora infection of leaves on cell death in greenhouse cucumbers, T1:15kg rice hull treatment, T2: 20kg rice hull treatment, T3: 25kg rice hull treatment, WT: no rice hull treatment is performed.

FIG. 5. indoor temperature variation of greenhouse for processing cucumber with different rice husk amount, T1:15kg rice hull treatment, T2: 20kg rice hull treatment, T3: 25kg rice hull treatment, WT: no rice hull treatment is performed.

FIG. 6. humidity change in greenhouse of cucumber treated with different rice husk amounts, T1:15kg rice hull treatment, T2: 20kg rice hull treatment, T3: 25kg rice hull treatment, WT: no rice hull treatment is performed.

Detailed Description

The technical solutions of the present invention will be clearly and completely described below in connection with specific embodiments, but it should be understood by those skilled in the art that the embodiments described below are only for illustrating the present invention and should not be construed as limiting the scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without any inventive step, are within the scope of the present invention.

Glumes are dry, scaly protective shells wrapped around grains. In gramineae, such as rice, barley, oats, and wheat, mature seeds are wrapped by a thin layer of dry scaly bracts (also called glumes, lemma, palea) to form dry husks. The husks after the peeling are called glumes.

The inventor of the application surprisingly finds that glumes of gramineae can effectively prevent and control occurrence and harm of downy mildew of greenhouse crops, and reduces the dosage of chemical pesticides, thereby putting forward the invention.

In a first aspect, the present invention provides a method for controlling downy mildew of a greenhouse crop, comprising the steps of: glumes are spread in the greenhouse crop cultivation room.

In embodiments of the invention, glume application may be performed during the growth phase of the greenhouse crop. It will be appreciated by those skilled in the art that the division of growth periods may be different for different greenhouse crops, for example in the case of cucumbers, glumes may be applied during the bouquet stage, full bloom stage, first fruit stage, full fruit stage, or young fruit stage; for example, in the case of tomatoes, glume may be applied at seedling stage, flowering and fruit setting stage, fruiting stage, and maturation stage. Thus, in a particular embodiment of the invention, the application of the glumes may be carried out during any of the above-described growth periods. In a preferred embodiment of the method of the invention, glumes are applied during the plantlet stage or seedling stage of the greenhouse crop. The application is carried out in the cluster stage or seedling stage of the greenhouse crops, which is more favorable for improving the soil temperature, protecting the soil moisture content and promoting the growth of the root system of the cucumber seedlings, and the application in the cluster stage or seedling stage is favorable for the application operation. In embodiments of the invention, application may be performed manually or by machine, typically by machine, to reduce capital investment, due to the simplicity and ease of application of the hulls.

In an embodiment of the method of the invention, the glume is a gramineous glume, such as rice hull, barley hull, oat hull, wheat hull, millet hull, preferably rice hull. In a preferred embodiment of the present invention, the glumes are glumes that are sealed with a film after a high-temperature natural fermentation treatment for about 20 to 30 days. High temperature natural fermentation can generally be carried out by: the glumes are stacked and covered with films in summer, and then fermented for about 20-30 days under natural conditions. In a further preferred embodiment of the invention, the glumes are rice hulls covered with a film and sealed after a high temperature natural fermentation treatment for about 20-30 days. Without being bound by theory, it is believed that the rice hull starch and unconverted saccharide have higher content, higher hardness of rice hull particles, compact structure, and relatively less varieties of microorganisms in the hulls, compared with other gramineous crop glumes, and the varieties and the number of pathogenic microorganisms are reduced.

In embodiments of the methods of the present invention, glumes may be used in an amount of about 1.0kg/m based on the area of a row of greenhouse crop cultivation rooms²To 5.0kg/m²For example, about 1.5kg/m²To 4.5kg/m²、2.0kg/m²To 4.0kg/m²、2.5kg/m²To 3.5kg/m². In particular embodiments, the glume amount, particularly after about 20-30 days of the film-sealed high-temperature natural fermentation treatment, and most particularly, the rice hull amount after about 20-30 days of the film-sealed high-temperature natural fermentation treatment, may be about 1.1kg/m, based on the area of the row of the greenhouse crop cultivation room, and may be about 1.1kg/m²、1.2kg/m²、1.3kg/m²、1.4kg/m²、1.5kg/m²、1.6kg/m²、1.7kg/m²、1.8kg/m²、1.9kg/m²、2.0kg/m²、2.1kg/m²、2.2kg/m²、2.3kg/m²、2.4kg/m²、2.5kg/m²、2.6kg/m²、2.7kg/m²、2.8kg/m²、2.9kg/m²、3.0kg/m²、3.1kg/m²、3.2kg/m²、3.3kg/m²、3.4kg/m²、3.5kg/m²、3.6kg/m²、3.7kg/m²、3.8kg/m²、3.9kg/m²、4.0kg/m²、4.1kg/m²、4.2kg/m²、4.3kg/m²、4.4kg/m²、4.5kg/m²、4.6kg/m²、4.7kg/m²、4.8kg/m²、4.9kg/m²、5.0kg/m²Preferably about 3.5kg/m²。

In a second aspect, the present invention provides the use of glumes for the control of downy mildew of greenhouse crops.

In an embodiment of the second aspect of the present invention, the glumes are glumes sealed with a film after a high-temperature natural fermentation treatment for about 20 to 30 days.

In an embodiment of the second aspect of the invention, the glume is a gramineous plant glume, such as rice hull, barley hull, oat hull, wheat hull, millet hull, preferably rice hull.

In a preferred embodiment of the second aspect of the invention, the glumes are rice hulls covered with a film and sealed after a high temperature natural fermentation treatment for about 20 to 30 days.

In a third aspect, the present invention provides the use of glumes for the preparation of a composition for controlling downy mildew of greenhouse crops.

In an embodiment of the third aspect of the present invention, the glumes are glumes sealed with a film after a high-temperature natural fermentation treatment for about 20 to 30 days.

In an embodiment of the third aspect of the invention, the glume is a gramineous glume, such as rice hull, barley hull, oat hull, wheat hull, millet hull, preferably rice hull.

In a preferred embodiment of the third aspect of the invention, the glumes are rice hulls covered with a film and sealed after a high temperature natural fermentation treatment for about 20-30 days.

In embodiments of the third aspect of the invention, the composition may also include other ingredients that help control downy mildew of greenhouse crops, or that facilitate growth of greenhouse crops, such as agrochemicals, agricultural organic or inorganic fertilizers, bactericides, insecticides, and the like.

In an embodiment of the present invention, the downy mildew may be, for example, grape downy mildew, cucumber downy mildew, tomato downy mildew, asparagus lettuce downy mildew, watermelon downy mildew, cabbage downy mildew, soybean downy mildew. In a preferred embodiment of the invention, the downy mildew is cucumber downy mildew.

Without being limited by theory, it is believed that the accumulated glume temperature of wheat hulls, barley hulls, rice hulls and the like reaches more than 40 ℃ in summer high-temperature seasons, and beneficial microorganisms such as a large number of high-temperature resistant cellulolytic bacteria, hemicellulose lytic bacteria, bacillus subtilis, actinomycetes, proteolytic bacteria and the like can easily survive and propagate, the decomposition of organic matters such as glume fibers, proteins and the like is accelerated, the glume accumulated organic nutrient content is increased after the glume is treated for about 1 month under the high-temperature condition, the glume accumulated organic nutrient content is increased, the soil cultivation is beneficial to the glume mixing into soil, the organic matter content of the soil and the soil environment temperature are effectively increased, the growth vigor of vegetables is promoted, roots and seedlings are strengthened, and the disease resistance of vegetable crops is enhanced. In addition, the glume accumulated materials after being dried are applied to the protected vegetable field, so that the evaporation and the dissipation of soil moisture can be effectively prevented, the moisture in the air can be absorbed timely, the moisture in the air can be favorably infiltrated into the soil, the soil moisture content is increased, the irrigation frequency is reduced, and the soil temperature is increased. By applying glumes, the soil structure and environmental conditions of greenhouse vegetables are effectively improved, the content of soil organic matters is increased, the growth vigor and disease resistance of vegetable crops are enhanced, the evaporation and loss of soil moisture are reduced, the air moisture and soil moisture of a vegetable habitat are recycled (the water recycling process shown in figure 1), the relative humidity of the vegetable habitat of a protected area is reduced, the propagation and infection of germs on leaves of the greenhouse vegetables are effectively inhibited, the occurrence and harm of leaf diseases are reduced, benign cyclic ecological conditions suitable for healthy growth of the vegetables in the protected area are established, and the aims of improving the yield of the vegetables, and achieving high quality and no public nuisance are achieved.

Unless specifically stated or otherwise apparent from the context, the term "about" as used herein is to be understood as being within the normal tolerance of the art, e.g., within two standard deviations of the mean. "about" can be understood to be within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05% or 0.01% of the stated value. All numbers provided in the specification and claims are to be modified by the term "about" unless the context clearly dictates otherwise.

Preferred embodiments of the present invention will be described in detail with reference to the following examples. It is to be understood that the following examples are given for illustrative purposes only and are not intended to limit the scope of the present invention. Various modifications and substitutions may be made by those skilled in the art without departing from the spirit and scope of the invention, and all such modifications and substitutions are intended to be within the scope of the claims.

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified. Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

Example 1 application of Rice husks to control greenhouse cucumber downy mildew

1. Materials and methods

1.1 Rice husk Material treatment

Purchasing a proper amount of rice hull materials, laminating, sealing and naturally fermenting for 20-30 days at high temperature after rice hulls are stacked in high-temperature seasons in summer, and then placing the rice hulls suitably.

1.2. Cucumber rice husk covering and applying technology for greenhouse in protected area

1) The rice hull materials after natural fermentation treatment are subjected to inter-application rice hull material treatment in the greenhouses in the protected area during the cucumber clustering period, and the fact that no rice hull is applied in the inter-cucumber interval is taken as a control, as shown in fig. 2.

2) And selecting 4 cucumber greenhouses to carry out rice hull application treatment, wherein the transplanting line length of the cucumbers is 8 meters, the line spacing is 90 centimeters, the rice hull application amount of each cucumber greenhouse row is 15kg, 20kg and 25kg respectively, and the rice hull application amount of each cucumber greenhouse row is continuously repeated for three years by taking the fact that no rice hull application treatment is carried out on the cucumber rows.

2. Index and method for measurement

2.1 investigation method for occurrence of cucumber downy mildew

The investigation of 3 cucumber greenhouses and 1 control greenhouse which are subjected to the different rice hull quantities starts from sporadic incidence of cucumber downy mildew, the investigation is carried out 1 time at intervals of 7 days, samples are taken at 5 points of a diagonal line of each investigation, 100 plants are investigated at each point, and the investigation is carried out 5 times continuously.

2.2 grading Standard of cucumber downy mildew and calculation of disease index

Level 0: the cucumber leaves have no downy mildew spots;

level 1: the area of the downy mildew spots is below 1/4;

and 2, stage: most diseased leaves, few downy mildew; or a few diseased leaves and a plurality of downy mildew;

and 3, level: most diseased leaves, most downy mildew;

4, level: most leaves are dry or dead;

the disease index is 100 × Σ (number of diseased leaves at each stage × representative plants at each stage)/(total number of examined leaves × representative value at the highest stage).

2.3 cucumber downy mildew infection leaf cell necrosis trypan blue staining detection

(1) Trypan blue dye solution: mixing 10g phenol, 10ml glycerol, 10ml lactic acid, 10ml deionized water and 0.02g trypan blue;

(2) chloral hydrate solution: dissolving 1kg of chloral hydrate in 400ml of deionized water to prepare a chloral hydrate solution;

(3) placing the infected cucumber leaf into a beaker containing a staining solution (mixed with trypan blue: alcohol: 1: 2) and carrying out water bath for 2min with boiling water;

(4) pouring the cucumber leaves and trypan blue dye solution into a large culture dish together, soaking and standing overnight for 1 (about 12 hours);

(5) the next day, the chloral hydrate is used for decoloring, and the chloral hydrate is replaced every 12 hours until the leaves are completely decolored;

(6) soaking in 95% ethanol;

(7) and observing the infection area.

2.4 indoor air temperature and humidity measurement of cucumber greenhouse

Before field planting, respectively hanging an air thermometer and an air hygrometer in the 3 processed cucumber greenhouses and the 1 unprocessed cucumber greenhouses, wherein the thermometer and the hygrometer in each greenhouse are uniformly distributed at 5 positions, the height of the hung greenhouse is about 60cm away from the ground, and the temperature and the humidity are respectively measured in a clumping period, a full flowering period, an initial fruit period, a full fruit period and a final fruit period, wherein the measurement time is 6:00 in the morning to 6:00 in the next day, and the measurement is carried out once every 3 hours. The temperatures and humidities of the cucumbers in different growth periods are the average values of statistics of each temperature and humidity, and the temperatures and humidities at different moments are the average values of temperature and humidity data at different moments in different periods.

3. Data processing method

And adopting Office2003 software Excel to perform data processing, tabulation and drawing. The significance analysis of the data was performed using PPSS18.0 statistical software.

4. Results and analysis

4.1. Comparative analysis of degree of damage caused by cucumber downy mildew

4.1.1 comparative analysis of disease indexes of cucumber downy mildew treated by different rice hull amounts

As shown in fig. 3, compared with greenhouse cucumbers without rice hull treatment (control), the greenhouse cucumbers treated by different rice hull amounts (15kg, 20kg and 25kg) have gradually increased damage of downy mildew from the head-up stage to the end fruit stage, but the damage of the head-up stage is the lightest, and the disease index is almost close to that of the control greenhouse. The damage degree of downy mildew during the full-bloom stage to the non-fruit stage is gradually increased, the damage degree of downy mildew during the last fruit stage is the heaviest, but the damage degree of downy mildew during the full-bloom stage, the initial fruit stage, the full-fruit stage and the non-fruit stage is gradually reduced compared with that of a control shed, the damage degree of downy mildew during the 5 key development stages of greenhouse cucumbers treated by 15kg, 20kg and 25kg of rice hulls is obviously reduced compared with that of the control shed, the reduction range is 30-50%, and the reduction range of the downy mildew during the greenhouse cucumbers treated by 25kg of rice hulls is about 50% compared with that of the control shed, so that the 25kg of rice hull treatment has an obvious prevention and control effect on the damage of the downy mildew in the greenhouse cucumbers.

4.1.2 comparison of cell death conditions caused by different rice husk amounts when greenhouse cucumbers are treated to influence downy mildew infection on leaves

After cucumber downy mildew infects cucumber leaves, leaf cell death is easily caused, and the difference of the death degree of the leaf cells caused by the infection of the downy mildew can be used as the basis for evaluating the harmful degree of the infection of the downy mildew. Fig. 4 shows greenhouse cucumber leaves in the bunch planting period, full flowering period, primary fruiting period, full fruiting period and non-fruiting period, which are treated by 15kg, 20kg and 25kg of rice hulls after cell death trypan blue staining technology, and the results show that the degree of cell necrosis caused by infection of the cucumber leaf downy mildew treated by different rice hulls is obviously different, and compared with cucumber leaves not treated by rice hulls, the degree of cell necrosis of leaves treated by 15kg of rice hulls is more than that of leaves treated by 20kg of rice hulls is more than that of leaves treated by 25kg of rice hulls. In addition, the cucumber is relatively light in morbidity due to downy mildew infection from the early growth and the early flowering stage to the full flowering stage, the cell death degree is relatively weak, the damage of the cucumber downy mildew from the early fruiting stage to the late fruiting stage is gradually increased, and the death degree of leaf cells is gradually increased, but the death degree of the leaf cells induced by downy mildew infection is gradually reduced along with the increase of the rice hull treatment amount in the five key development stages of the cucumber. Comprehensive related results show that the rice hull treatment greenhouse cucumber can effectively inhibit downy mildew infection and cause cell necrosis, wherein 25kg of rice hull treatment obviously inhibits downy mildew infection and cell necrosis, and the result is basically consistent with the index change trend of damage caused by downy mildew of cucumbers treated with different amounts of rice hulls.

4.2 influence of different rice husk amount treatments on ecological temperature and humidity of greenhouse cucumbers

4.2.1 Effect of different Rice husk amount treatments on indoor temperature of greenhouse cucumber

As can be seen from FIG. 5, the average daily temperature of greenhouse cucumbers treated by rice hulls is higher than that of a control greenhouse without rice hulls (the time measured every day is 6:00 in the morning to 6:00 in the next day, and the time is measured every 3 hours), 15kg of rice hulls are increased by 1.2 ℃ compared with the control greenhouse, 20kg of rice hulls are increased by 2.04 ℃ compared with the control greenhouse, 25kg of rice hulls are increased by 3.4 ℃ compared with the control greenhouse, the temperatures of the cucumber greenhouses treated by different amounts of rice hulls in different growth periods are obviously increased, the increase range of the growing period is 1.1-3.0 ℃ compared with the control greenhouse, the increase range of the full bloom period is 1.5-3.0 ℃ compared with the control greenhouse, the increase range of the primary fruit period is 1.0-4.0 ℃ compared with the control greenhouse, the increase range of the full fruit period is 1.2-3.3 ℃ compared with the control greenhouse, and the increase range of the non-fruit period is 1.2-3.7 ℃. The related data fully indicate that the greenhouse cucumber treated by the rice husks can effectively improve the greenhouse room temperature, and the rice husk treatment of 25kg enables the greenhouse temperature to be increased to the maximum, so that the change range of the room temperature caused by outdoor temperature change is reduced, and the room temperature of the cucumber in different growth periods is ensured to be higher than 23 ℃ suitable for the propagation of cucumber downy mildew. Therefore, aiming at the characteristic that the cucumber downy mildew is a low-temperature disease, the rice hull treatment greenhouse cucumber has the effect of effectively improving the room temperature, can effectively inhibit the propagation and infection of the cucumber downy mildew, and the 25kg rice hull treatment greenhouse cucumber more effectively inhibits the propagation and infection of the cucumber downy mildew.

4.2.2 Effect of different Rice husk treatment on indoor humidity of greenhouse cucumber

As can be seen from fig. 6, the average air humidity of the cucumber greenhouses treated with different rice hull amounts is larger than that of the untreated cucumber greenhouses. Compared with a greenhouse without rice hull treatment, the relative humidity in the greenhouse from the bulk stage to the non-fruit stage of the cucumber greenhouse treated by 15kg, 20kg and 25kg of rice hulls is gradually reduced, the relative humidity in the greenhouse from the bulk stage to the non-fruit stage is 64.68%, the relative humidity in the greenhouse treated by 15kg of rice hulls is 60.45%, the relative humidity in the greenhouse treated by 20kg of rice hulls is 57.7%, and the relative humidity in the greenhouse treated by 25kg of rice hulls is 42.78%. The indoor relative humidity of the contrast greenhouse in the full-bloom period is 68.45%, the indoor relative humidity of the greenhouse treated by 15kg of rice husks is 60.5%, the indoor relative humidity of the greenhouse treated by 20kg of rice husks is 57.7%, and the indoor relative humidity of the greenhouse treated by 25kg of rice husks is 40.57%. The indoor relative humidity of the comparison greenhouse in the primary fruit period is 70.78%, the indoor relative humidity of the greenhouse treated by 15kg of rice husks is 60.56%, the indoor relative humidity of the greenhouse treated by 20kg of rice husks is 52.45%, and the indoor relative humidity of the greenhouse treated by 25kg of rice husks is 38.67%, and compared with the comparison greenhouse, the relative humidity of the greenhouse in the primary fruit period treated by 25kg of rice husks is reduced by 45.36%, more than 20kg of rice husks is reduced by 25.89%, more than 15kg of rice husks is reduced by 14.44%. Compared with the contrast greenhouse, the greenhouse indoor relative humidity for full bearing period is 72.56%, the greenhouse indoor relative humidity for 15kg of rice hull treatment is 58.67%, the greenhouse indoor relative humidity for 20kg of rice hull treatment is 48.9%, and the greenhouse indoor relative humidity for 25kg of rice hull treatment is 36.45%, and the greenhouse indoor relative humidity for the green bearing period for 25kg of rice hull treatment is reduced by 49.76% and is greater than 20kg of greenhouse relative humidity for the green bearing period for 20kg of rice hull treatment and is reduced by 32.26% and is greater than 15kg of greenhouse relative humidity for the green bearing period for 15kg of rice hull treatment and is reduced by 19.14%. The indoor relative humidity of the comparison greenhouse in the immature period is 67.67%, the indoor relative humidity of the greenhouse treated by 15kg of rice husks is 58.9%, the indoor relative humidity of the greenhouse treated by 20kg of rice husks is 50.23%, and the indoor relative humidity of the greenhouse treated by 25kg of rice husks is 41.34%, compared with the comparison greenhouse, the relative humidity of the greenhouse treated by 25kg of rice husks is reduced by 38.9%, more than 20kg of the greenhouse treated by 20kg of rice husks is reduced by 25.87%, more than 15kg of the greenhouse treated by 15kg of rice husks is reduced by 13.07%. Comprehensive comparison shows that the relative humidity of the cucumber in the greenhouse in five key growth periods is obviously reduced by processing the cucumber greenhouse with different rice hull amounts, the relative humidity in the greenhouse is obviously reduced by processing the rice hulls aiming at the fact that the cucumber downy mildew is a high-humidity disease, and the humidity in the greenhouse is obviously reduced by processing the 25kg rice hulls, so that the propagation and infection of the cucumber downy mildew can be effectively inhibited.

Comprehensive comparison and analysis show that the rice hull treatment of greenhouse cucumbers obviously reduces the occurrence and harm of downy mildew in five key development stages of the cucumbers, and the effect of preventing and controlling the downy mildew of the cucumbers in 25kg rice hull treatment is more than 20kg rice hull treatment and is more than 15kg rice hull treatment. In addition, comprehensive analysis also finds that after treatment of different rice husk amounts, the relative humidity of five key development stages of the cucumber is obviously reduced, and the indoor temperature is obviously increased, so that the greenhouse ecological environment can effectively inhibit the occurrence and harm of high-humidity low-temperature cucumber downy mildew.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same. While the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: modifications may be made to the above-described embodiments, or equivalents may be substituted for some or all of the features thereof without departing from the concept, spirit and scope of the present invention; and such modifications or substitutions are intended to fall within the scope of the invention as claimed.