Cultivation techniques of Cucumber

Cucumber, also known as cucumber and cucumber, belongs to cucurbitaceae plants, widely distributed in all parts of China, and is one of the main greenhouse products. Cucumber stems are covered with hair, rich in juice, and the appearance of leaves has 3-5 lobes and fluff. Cucumber peel is originally turquoise, put for a long time will gradually turn yellow, also known as old cucumber.

Morphological characteristics

The root of cucumber is mainly concentrated in 0-30 cm, and the depth of the main root can reach 1 meter. Strong gas, cold resistance, weak ability to absorb fertilizer, shallow cultivation, suitable for fertile and loose soil. The root cambium is shallow, easy to aging, the seedling stage occurs quickly, the seedling time should not be too long, planting should protect the root system. The stem thickness, color and thorn hardness of cucumber are important indicators of plant growth and yield. Generally, the stem diameter is 0.6-1.2 cm and the Internode 5-9 cm.

The nutrients stored and produced by cotyledons are the main source of nutrition in the early stage of seedlings, and cotyledons are also an important sign to judge the growth environment of cucumbers. Cotyledons should be kept intact during cultivation. True leaves are large, thin, with large transpiration and tend to wilt when they are short of water. Monoecious and monoecious, with single-row fruiting characteristics. The flower bud differentiation of cucumber begins when the first true leaf appears, the growth point differentiation has differentiated to 12 nodes when the first true leaf unfolds, and all the leaf axils in 9 nodes have flower bud differentiation, but the sex type is undetermined. When the second true leaf unfolds, the flower bud differentiation has reached 12-16 nodes, and the 3-5 node sex type has been determined. When the seventh true leaf unfolds, the 26th flower bud has already differentiated, and the flower bud type within 16 nodes has been determined. Therefore, at the end of the seedling stage, whether each node in the middle and lower part of the plant is female or male has been decided. The number of female and male flowers is directly related to the environmental conditions. The suitable temperature during the day and the appropriate reduction of night temperature are beneficial to the formation of female flowers. When the first true leaf unfolds, the second true leaf is not yet unfolded, and the night temperature is 12-14 ℃. When the second true leaf expands, it can drop to 10-12 ℃, which is beneficial to the formation of female melon. When there are 1-5 true leaves, 8 hours of light a day is beneficial to the formation of female flowers, and the number of female flowers decreases in more than 12 hours. High water content is beneficial to the formation of female flowers, but too high is easy to grow, which is disadvantageous to the formation of female flowers. One-time application of nitrogen and phosphorus was disadvantageous to the formation of female flowers, and more female flowers were used by stages, for example, the female-to-male ratio of one-time application was 1 / 91, and that of three-time application was 1:65. Timely use of ethephon or Zenggualing can reduce male flowers, while silver nitrate treatment can reduce female flowers.

Birth cycle

1. Germination period: from sowing to the appearance of the first true leaf, generally 5-7 days, the growth at this stage is small, the speed is slow, and high temperature and humidity and sufficient light are needed to promote early emergence, neat emergence and prevent overgrowth.

2. Seedling stage: it usually takes about 30 days from the first true leaf to the 4th-5th true leaf. At this stage, flower bud differentiation begins, but the growth center is still root, stem, leaf and other vegetative organs. The management goal is to promote the combination of control and cultivate strong seedlings.

3. Early flowering stage (spreading stage): it takes about 20 days to expand from the 4th to 5th true leaves to the first female melon. At this time, vegetative growth and reproductive growth are carried out at the same time, and the growth center is gradually transformed from vegetative growth to reproductive growth.

4. Melon setting period: from the first female to pulling seedlings, the duration varies with different cultivation methods. At this stage, the growth rate of plants slowed down, focusing on the development of fruit and flower buds. Adequate water and fertilizer should be provided to promote melon bearing and prevent premature senility.

Cultivation techniques of ground Cucumber

1. Variety selection

The varieties with high yield, strong disease resistance and good marketability should be selected, which are suitable for spring open field cultivation, such as Jinchun 4, Zhongnongda 11, Zhongnongda 12, Bomei 4, Derit 902, Zhongnong 12, etc. the varieties suitable for autumn open field cultivation are Jinyou 3, Jinyan 2, Tangshan autumn melon and so on.

2. Raising seedlings

Seedling age is about 35 days, strong seedling standard: cotyledons are intact, there are 3-5 true leaves, internodes are short, the angle between petiole and main vine is 45 degrees, leaf color is dark green, leaves are thick, stems are stout, roots are developed, and there are no diseases and insect pests.

3. Fertilizing to make beds

Soil preparation, fertilization mature organic fertilizer 5 cubic meters, calcium superphosphate 25-30 kg or diammonium phosphate 10-15 kg. Plough the border before planting, 1.2 meters wide, more than 15 centimeters high, and covered with plastic film.

4. Colonization

The main results are as follows: 1) the determination of planting period: it is planted as soon as possible on the premise of ensuring that it will not be frozen after planting, and Chengde area is generally planted at the end of April and the beginning of May. Temperature index requirements: the lowest night temperature is higher than 5 ℃, and the soil temperature at 0-10 cm is higher than 12 ℃. Cucumbers in autumn open field are direct seeded.

2) planting density: 4000mi 4500 plants / mu, small row spacing 40 cm, large row spacing 80 cm, plant spacing 25-30 cm, planting by dark water method.

3) Field management

A, insert rack: insert frame as early as possible after planting, prevent wind to draw seedlings, insert frame can use flower rack or herringbone frame, about 8-10 cm away from the root.

B, binding vine: using the "8" word method to bind the vine to prevent the abrasion and sagging of the stem vine. Every 2-3 knots, should be carried out in the afternoon, the stem is easy to break in the morning, the tightness of the binding vine should be strong and help the weak, for the plants with strong growth potential, tie a little tighter, and make the growth point of the same height.

C, pruning and pinching: the main vine should remove all the lateral branches, and the lateral vine should leave one or two leaves pinched after the melon, and knock off all tendrils. When the stem exceeds the shelf head, it should be pinched in time to promote the growth of the lower melon, and the method of twisting the tip can also be taken to restrain the growth of the upper part.

D, fertilizer and water management: timely watering and ploughing, the amount of water and times depend on the weather and growth period. Slow seedling water was irrigated 5-7 days after planting, water was controlled before setting, middle tillage and squatting seedlings, root melon was watered when 10~12cm was growing, and watering was done every 5-7 days in fruiting period. The principle of topdressing is light in front and heavy after a small amount of fertilizer is applied after root melon sitting, and full melon fertilizer is carried out after root melon harvest. Promote the use of organic fertilizer topdressing.

Cultivation techniques in plastic greenhouse

1. Variety selection

The varieties cultivated in early spring should choose the varieties with early maturity, strong cold tolerance and rapid fruit development. the suitable varieties are Jinyou 10, Bojie 10, Derit 721, Zhongnongda 21, Zhongnongda 22, Zhongnong 16 and so on. The varieties with strong disease resistance and concentrated melon should be selected in the late autumn, and the suitable varieties are Nongda 23, Derit 166, Zhongnong 12, Jinyou 1, Jinyou 5 and so on.

2. Raising seedlings

The seedling age of early spring stubble should be old, low temperature exercise should be sufficient before planting, and seedlings should be raised with nutrition cup or paper bag. The method of live broadcast can be used to postpone autumn.

3. Preparation before planting

Buckle the shed and roast ground early, buckle the greenhouse film 20-30 days before planting, and disinfect the old shed. Trisodium phosphate or sodium hypochlorite spray column and greenhouse film can be used, or smoke agents such as chlorothalonil can be used for fumigation. After thawing, ploughing the land in time and applying sufficient base fertilizer, the base fertilizer is mainly organic fertilizer, high border cultivation and plastic film mulching.

4. Colonization

Under the premise of ensuring that the seedlings are not damaged by freezing, the ground temperature of 10 cm in the greenhouse is more than 12 ℃, and the lowest night temperature is not less than 5 ℃. Moderately close planting, about 4000 plants per mu, moderate shallow planting.

5. Management after planting

1) temperature management

The early stage of cucumber cultivated in early spring is mainly heat preservation and cold proof. generally, there is no ventilation before the seedling stage to strengthen the cold prevention at night, and it takes about 7 days to slow the seedlings. Various measures are taken to improve the night temperature to promote slow seedlings. From slow seedling to root melon sitting stage for about 20 days, the temperature should be properly controlled, 20: 25 ℃ during the day and 12: 16 ℃ at night to control overgrowth. During the full fruiting period, the temperature should be properly controlled at 25: 30 ℃ in the daytime and 16: 18 ℃ at night.

2) Fertilizer and water management and mid-tillage

The soil temperature of cultivation in early spring is low, and the planting water should be properly small, slow seedling watering, mid-tillage and squatting seedling after watering. Water the root melon after harvest, and then water it every 5 days, preferably in the morning on a sunny day, and once after a rainstorm in summer. Timely ventilation after watering to reduce the air humidity in the shed. Topdressing can be applied 1-2 times from planting to root melon harvest, and once every 7-10 days. When diammonium phosphate and ammonium nitrate are used alternately, flushing fertilization can also be used with watering.

3) hanging vine and pruning

When the cucumber grows to 5 nodes, hang or transplant the seedlings in time, circle or bind the seedlings every 2-3 days, remove all side branches and tendrils in time, and pinch or twist the tip when approaching the greenhouse film. Get rid of the diseased old leaves in time.

Cultivation techniques in winter and spring in solar greenhouse

1. Variety selection

Cucumber should choose varieties with low temperature and weak light tolerance, vigorous plant growth but not easy to grow, few branches, low node position of female melon, good performance of melon, moderate size of melon strips, good appearance and flavor, high yield and strong disease resistance. Such as: Jinyou 35, Jinyou 38, Zhongnong 16, Zhongnong 29, Zhongnong University 31, Zhongnong University 32, Derit 943. The rootstock should have strong affinity, low temperature resistance and strong stress resistance, and the cucumber produced has no peculiar smell and good quality.

2. Raising seedlings

Timing of raising seedlings (take sunspot pumpkin as an example)

.tab {width:100%;border:1px solid # ccc;}. Tab td {border:1px solid # ccc} day 1, day 4, day 12, day 22, day 35, cucumber sowing, pumpkin grafting, root cutting and colonization.

3. Preparation before planting

1) cover greenhouse film and disinfect greenhouse

One month before planting, cover the greenhouse film, and carry out greenhouse disinfection, disinfection can use dichlorvos 200 ml, add 1.5-2 kg of sulfur, mix with sawdust and ignite, stuffy shed for 1-2 days, can effectively kill the disease and insect eggs in the shed. For the shed with severe root-knot nematodes, 80 kg of lime nitrogen can be applied per mu and fully mixed.

2) soil preparation and application of base fertilizer

The base fertilizer is mainly organic fertilizer, 10000 kg of fully mature organic fertilizer is applied per mu, and the depth is 40 cm. Can also be applied year after year to ferment rotten broken grass, wheat straw, rice husk and other organic matter. The best measure is the application of straw biological reactor technology, which can not only effectively increase soil temperature, increase soil organic matter, improve soil environment, but also reduce the occurrence of diseases, improve product quality, and increase production.

3) making bed and mulching with plastic film

Cucumber cultivated in greenhouse in winter should get up a high bed and adopt drip irrigation or dark irrigation under plastic mulch. The bed is 1.2 meters wide and 15 centimeters high, and mulched with plastic film. It can also be planted and then covered with film.

4) determination of planting period

Cucumbers in winter and spring are generally planted from late November to early December.

5) planting method and density

About 3500 plants are cultivated per mu. Planting seedlings should be strictly screened, diseased seedlings, weak seedlings and unqualified seedlings grafted should be removed, planting holes should be opened according to 28-30 cm plant distance, seedlings should be implanted into holes, watered, and then covered with plastic film.

4. Management after planting

1) Prophase management

From planting to harvesting, the management of this period is called Prophase management, and the center of Prophase management is to promote root and control seedling. Although the temperature and light have decreased significantly during this period, they have not yet reached the lowest point. It is necessary to make full use of the favorable climatic conditions in this period, strengthen management, promote root development, and enhance the adaptability of plants to low temperature, weak light and special weather. The technical level of early management has an important impact on plant growth, disease resistance, cold tolerance and yield in the middle and later stage.

A, irrigate the first three water: first, it is necessary to irrigate the planting water to prevent the soil and the surrounding soil from delaminating and affect the slow seedling. 15 days after planting, pour slow seedling water, which should be poured thoroughly from the dark ditch in the middle of the border, and the water level should be topped to the planting hole. The third water is poured on a sunny morning after root melon harvest, which is also called melon water.

B. Root promotion and seedling control: in order to promote seedling retardation within one week after planting, 25 ℃ 32 ℃ during the day and 15 ℃ at night. It is necessary to increase the amount of air release after slowing down seedlings, the highest is no more than 30 ℃ at noon in sunny days, 15 ℃ at night, and 10 ℃ before opening the curtain in the morning, to increase the temperature difference between day and night and control the growth of aboveground parts. If the temperature management is too high, the plant growth is too prosperous, and the ability to resist the cold current decreases in January and February, while the leaves are too large and the ground is seriously shaded, which will also affect the increase of ground temperature and the development of roots.

C, plant hanging vine and adjustment: when the plant grows to 6-7 leaves and begins to shake the vine, pull the line to lift the vine in time. With the growth of the stem vine, the stem vine is wound around the rope, and then every 2-3 days.

2) medium-term management

The management from root melon harvest to early March is called mid-term management. During this period, when the temperature is the lowest and the light is the weakest in cucumber production in winter, it is difficult to manage, and it is also the peak of output value.

A, temperature management: during this period, temperature management is the core. During the day, the sunshine time should be extended as much as possible. Under the premise of not affecting the indoor temperature, the grass curtain should be uncovered as early as possible and the night cover should be opened as early as possible, and four stages of temperature change management should be implemented. The temperature should be controlled between 25 ℃ and 32 ℃. In the afternoon, the photosynthetic capacity decreased significantly, and the temperature was maintained between 20 ℃ and 30 ℃. The indoor temperature dropped gently after the curtain was covered. The temperature was maintained at 20 ℃ at midnight and 10 ℃ at midnight, which was beneficial to nutrient transport and inhibited respiratory consumption. The ground temperature should be kept above 15 ℃. In the middle and last ten days of February, with the increase of air temperature, sunshine hours and light intensity, the nutrients produced by plants increased, and the night temperature should also be increased. 22-16 ℃ in the first half of the night and 15-12 ℃ in the second half of the night were beneficial to the transport of nutrients and the growth of melon strips.

B, humidity management: due to low temperature in winter and small indoor ventilation, it is easy to form a high humidity environment and various diseases occur. In view of this characteristic, the management measures of low temperature and low humidity should be implemented. The air humidity is controlled at 60 per cent 80% during the day and 85 per cent at night, and the leaves try not to form water droplets in the morning. The times of watering should be reduced as far as possible, no drought, no watering, and after water, aerosol and dust should be chosen as far as possible.

C, topdressing: with the increase of melon harvest, replenish nutrients in time. According to the yield and plant performance, determine the variety and quantity of topdressing, generally start to topdressing with water in the fourth water, if the leaves and melon strips are darker, topdressing is mainly nitrogen fertilizer, supplemented by phosphorus and potassium fertilizer, and pay attention to the supplement of calcium, magnesium and other trace elements. When applying, first dissolve the fertilizer and top up the fertilizer with water. If the plant color is lighter and the leaf is larger, it is mainly topdressing phosphorus and potassium fertilizer. The amount of topdressing should follow the principle of "eat less and eat more" to avoid excessive topdressing at one time. After March, dilute manure and biogas residue can be applied in combination with watering, but it should be noted that it must be fully mature and fermented.

3) late management

A, falling vine picking leaves: with the growth of the plant and the continuous harvest of melon strips, falling vines should be taken when the growth point is close to the roof. The method is to untie the plastic rope tied to the iron wire above the falling vine, make the cucumber growing point fall to a suitable height and then tie it again, and remove the lower old and diseased leaves in time before falling the vine, which can reduce nutrient consumption, improve ventilation and light transmission conditions, and avoid the spread of diseases.

B. Strengthen the management of water and fertilizer and prolong the harvest period: after April, in order to prevent plant senescence and de-fertilizing and prolong the harvest period as far as possible, attention should be paid to strengthening the management of fertilizer and water, generally watering water once every 7 days and dressing once every 10 days. And ensure the quality of flushing fertilization. If there is a flower hitting the top, showing an atrophic shape, you can take a stuffy tip to pick the heart to promote the growth of melon. In order to improve the commodity rate of melon strips, curved melons, diseased melons and superfluous melons should be removed in time. The harvest must be timely, and the harvest should not be delayed to affect the commodity rate and total output of melon sticks.

4) Management of special weather

In the case of cold spell, overcast snow and continuous overcast weather, special management measures should be implemented to reduce or avoid production losses caused by disastrous weather.

When the strong cold current comes, strictly prevent the cold and keep warm, add paper quilts, straw curtains and other coverings, and take measures such as temporary heating, lighting stoves, lighting light bulbs and so on.

When it snows, it should be cleaned in time to prevent the snow on the shed surface from increasing the overload of the skeleton and causing the greenhouse skeleton to collapse.

Harvest melon strips as early as possible in continuous cloudy days to reduce the nutrient consumption of melon strips, and try to open the grass curtain to strive for scattered light for a certain time without significantly affecting the drop of indoor temperature. Foliar topdressing is carried out after the weather suddenly clears up to quickly replenish nutrients and increase humidity in the shed. If the leaves are seriously wilted, temporary return can be carried out appropriately.

5. Harvest

Cucumber is suitable for early harvest, single melon weight 100-150 grams in the early stage, 150-250 grams in the middle and later stage, especially root melons must be picked early to make the upper melons and vines grow at the same time. Early continuous cloudy days should be picked in time to prevent premature senility or disease.

Physiological disorders of cucumber

1. Melons

After flowering, when the melon length is about 8~10cm, the melon strips no longer elongate and expand, and the front end gradually wilts and turns yellow, and then the whole melon gradually dries up. The main reasons are improper cultivation and management measures, insufficient supply of water and fertilizer, too many melons, untimely harvest, poor plant growth, insufficient light, too low or too high temperature, and so on.

2. Bitter melon and its causes.

It is mainly due to the bitter substance cucurbitacin in the fruit, and the main reason for bitter melon is partial application of nitrogen fertilizer, lack of watering and so on. Uncomfortable environmental conditions can also cause the formation of bitter gourd, such as persistent low temperature, weak light, poor soil texture and so on.

3. Malformed melons

The main symptoms are bee waist melon, sharp mouth melon, big belly melon, curved melon, stiff melon and so on. The reasons for the formation are improper cultivation and management measures, such as weak plant growth caused by improper management of water and fertilizer, improper treatment of ethephon, poor pollination and fertilization caused by high temperature and low temperature, high temperature and drought and air drying. In addition, deformed melons can be formed when the soil is deficient in B and K.

4. Hypothermia disturbance

[symptoms] Cucumber has weak tolerance to low temperature, and continuous low temperature will cause a variety of symptoms: low ground temperature during sowing, delay in seed germination and emergence, resulting in yellow and weak seedlings, retting seeds or quenching disease, root rot disease and so on. Some unearthed seedlings showed white edges on the edge of cotyledons, the leaves turned yellow and the roots did not grow; if the ground temperature was lower than 12 ℃ for a long time, the root tips turned yellow or retted roots and rotted roots, and the aboveground parts began to turn yellow. After the occurrence of cold injury or frost injury after planting, the leaf color was dark green, the leaf margin was slightly curled, and yellow-white spots appeared between the veins of large leaves. Or the plant roots slowly, or no roots, or flower buds are not differentiated, the whole plant grows thin, flowers top, and even the leaves die until the whole plant dies.

[prevention and control methods]

The main results are as follows: 1) the low temperature tolerant varieties with fast germination, rapid emergence and fast seedling growth were selected.

2) the fast-germinating seeds soaked in 0 ℃ for 24 hours and 36 hours after sowing can enhance the cold resistance.

3) avoid raising seedlings and planting in cold period. Heating measures such as lighting a stove in the shed or the Quiga hotline.

4) compost or fully mature organic fertilizer retted by enzyme bacteria.

5) spraying plant anti-cold agents before the cold spell, 100,200 milliliters per mu, 7500 times of Baolifeng antifreeze or 3.4% Biwei wettable powder, or 50 grams of brown sugar in a barrel of water plus 0.3% potassium dihydrogen phosphate.

6) if the temperature is too low and frost damage has occurred, slow warming measures should be adopted. For example, after a long cloudy and sunny day, cover the light with grass curtains, so that the physiological function of cucumbers slowly recover, do not act in undue haste.

5. Element deficiency

1) potassium deficiency

A slight yellow flower appears at the leaf margin, then the leaf edge dies, and the leaf curls outward as the leaf grows. The method of prevention and control is to apply potash fertilizer in time, and then supplement potash fertilizer at the same time as iron fertilizer.

2) magnesium deficiency

The mesophyll between the veins of the lower leaves of cucumber gradually lost green and turned yellow, and further developed, except for a little green on the edge of the leaves, and in severe cases, the upper leaves also turned yellow from the inside. The control method is to increase the application of organic fertilizer, formula fertilization, to avoid partial application of nitrogen fertilizer caused by soil acidity affecting the absorption of calcium and magnesium. When magnesium is deficient, leaves can be sprayed with 1% Mel 2% magnesium sulfate, etc., and pay attention to magnesium supplement combined with potassium supplement and zinc supplement.

3) Boron deficiency

When boron deficiency occurs, the growth point is necrotic, the floral organ is not fully developed, the leaves, stems and fruits stop growing, the leaf margin is yellowed, the yellowed part is wide, and there are cracks in the pericarp. Control measures to increase the application of stable fertilizer, do not apply too much lime, reasonable watering. To supplement boron fertilizer in time, chelated boron series can be used to avoid soil damage caused by single application of borax fertilizer.

6. Obstacles to soil salinization

Symptoms: due to the application of a large amount of chemical fertilizer in the solar greenhouse or greenhouse in successive years, and the high temperature in the greenhouse promotes the evaporation of a large amount of surface water, the soil mineral nutrients accumulate on the soil surface with the increase of moisture, and the greenhouse film is covered every year, so that the indoor soil is not washed and drenched by Rain Water, resulting in soil secondary salinization and long-term accumulation of surface salt to form a thick layer of green moss. It not only affects root growth and the absorption of water and nutrients, but also induces element deficiency, such as magnesium deficiency, calcium deficiency, boron deficiency and so on. The plant is short and grows slowly, the root system does not stick and gather around the main root, the leaf is small, the leaf color is dark green and dull, the flowering and fruiting is few, the melon is small, the deformed melon is many, the yield decreases obviously, and the melon seedling wilts when it is serious.

[prevention and control methods] increase the application of organic fertilizer, turn the soil deeply, and try not to use or use less chemical fertilizers that are easy to form salts in the soil, such as ammonium sulfate and so on. Irrigate a lot of water to press the salt when the farm is idle, or uncover the film in the summer leisure period, let Rain Water rush and press the salt. Grafting cucumber with black seed pumpkin can improve salt tolerance and reduce or avoid salt damage; plastic film mulching in greenhouse can obviously inhibit surface evaporation and play a certain role in salt inhibition.

Control techniques of main Diseases of Cucumber

1. Downy mildew

It is a fungal disease, its incidence site is in the middle and upper leaves of cucumber, the following main points should be grasped when observing in the field, about 8: 00 a. M. every day, to see whether there are water-immersed, polygonal spots and gray mold layers on the back of the leaves. If you have these three points, you can be diagnosed as downy mildew. The suitable disease environment is 16 ℃ ~ 22 ℃, and the relative humidity is more than 83%. The disease germs have two fears, that is, they are afraid of dryness and high temperature. The germs died naturally in 3 to 5 days when they were dry. In the case of high humidity in the shed, the temperature can be controlled to 45 ℃ for 2 hours, and the disease can be easily controlled by spraying appropriate chemicals.

[chemical control] you can choose Anke, Prike, Mike, Frost Urea Manganese Zinc, Yikuangjing, Jinreidi and Amisida. In addition, in the prevention and control of downy mildew, we should pay attention to the simultaneous occurrence of bacterial angular spot, which can be added to the agents for the prevention and control of downy mildew.

2. Grey mold

[symptoms] can be harmful melons, leaves and stems. In order to infect the fallen flowers first, make the flowers rot, grow a grayish brown mildew layer, and then further infect the young melons, the killed melons quickly soften, atrophy and rot, and there is a dense gray-white mildew layer on them. Leaf disease is mostly round, nearly round to irregular disease spot, 20-50 mm in diameter, the edge of the disease spot is obvious, the surface is light reddish brown, with a small amount of gray mold. The damage to the stem caused local decay, and in serious cases, the diseased stem was broken and the whole plant died. The diseases caused by fungal infection often occur in the greenhouse when the humidity is high, the ventilation is not timely and the temperature is low. Temperature about 20 ℃, lack of light in cloudy days, relative humidity above 90%, and long condensation time are important conditions for the occurrence and spread of Botrytis cinerea. If the temperature is higher than 30 ℃ and the relative humidity is below 90%, the disease will stop spreading.

[chemical control] 10% Sukeling smoke agent or 45% chlorothalonil smoke scavenger can be used in the initial stage of disease in the protected area, 250 grams per mu each time, fumigation for 3 hours for 4 hours. You can also use 1500 times of 50% prohydantoin wettable powder, or 2.5% of Xerox wettable powder, or 50% rimakang, or 25% acemida suspension 1500 times. The medicine should be used every 6-7 days for 3-4 consecutive times, requiring the medicine to be sprayed on flowers and young melons. In the initial flowering stage, adding 0.1% of the dosage of 50% Sukeling wettable powder or 25% Shile wettable powder 200-300 times solution or spray flower effect is obvious.

3. Powdery mildew

[symptoms] small round white powdery mildew spots first grew on the front or back of the lower leaves, gradually enlarged, thick, and soon became one. In the later stage of the disease, the whole leaf was covered with white powder, then turned gray, and finally the leaf was yellowish brown and dry. Similar disease spots and dense powdery mildew spots are also produced on stems and petioles. In autumn, sometimes yellowish-brown dots are produced in the sick class, and then turn black. The disease is covered with white powder in the leaves, and the lower epidermis of the mildew layer remains green at the initial stage of the disease, which is easy to distinguish from other leaf diseases. The suitable temperature and relative humidity of the disease are 20-25 ℃ and 35-45%, respectively. Therefore, the requirements of powdery mildew for temperature and humidity are neither hot nor cold, neither dry nor wet. Young and overgrown plants are susceptible to the disease.

[prevention and control methods]

Powdery mildew is particularly sensitive to "sulfur". Before planting, fumigation is ignited with 1.8 kg of sulfur powder per mu plus sawdust or other accelerants, which can kill powdery mildew, fumigate again every 3 days, and then sow or plant. During the growth period of cucumber, the amount of sulfur powder can be reduced by half, the time can be reduced to one night, and it can be smoked again every 5-7 days, and the effect is good. When central diseased plants occur in the field, spray and control in time, you can choose 1000 times liquid of 20% triadimefon wettable powder or 500 times liquid of 75% Dakening wettable powder, or 2500 times higher than 10%, or 2% plus 400 times of rice, etc., spray once every 5 to 7 days, and pesticides are used alternately. When spraying, don't ignore spraying on the ground.

4. Virus disease

[symptoms] cucumber virus disease mainly harms leaves and melons. It can occur at both seedling stage and adult stage. In the seedling stage, the diseased cotyledons turned yellow and withered, and the young leaves showed mosaic shape alternately between dark green and light green. In the adult stage, the diseased plant was short and small, the internodes were short and thick, the leaves were obviously wrinkled and thickened, the new leaves showed yellow-green mosaic, when the diseased leaves were serious, the lower old leaves of the diseased plants gradually withered and yellow. The melon strips stopped growing after the disease, and the surface showed dark and light green spots. In severe cases, the surface of the melon is uneven or deformed, the seriously affected plants, internodes shorten, clustered leaflets, do not bear melons, resulting in atrophy and death. It is mainly transmitted by aphids, planthoppers and field operations. The disease is serious under the conditions of high temperature, drought and strong sunshine. The disease is serious when there is lack of water, fertilizer, extensive management and many aphids.

[prevention and control methods] when raising seedlings, sunshade nets are used to cool and shade, away from diseased crops. Immediately after transplanting, "Tianda 2116" 1000 times solution + Tianda Yufeng 1000 times solution was sprayed and irrigated to promote seedling disease prevention. At the initial stage of the disease, 20% doxorubicin 500 times solution or 20% virus A500 solution can be sprayed once every 7 days.

5. Bacterial angular spot

[symptoms] the round or oval water-immersed spots on the cotyledons of the seedling stage were slightly sunken, and then turned brown and withered. At the adult stage, the size of the primary needle on the leaf is water-immersed spots, and the expansion of the disease spot is polygonal due to the limitation of the leaf vein. when the humidity is high, milky mucus is produced on the disease spot on the back of the leaf, and a layer of white film or white powder is formed after drying. the disease spot is brittle and easy to perforate in the later stage. The diseased spots on stems, petioles and young melon strips are immersed in water, nearly round to oval, and then light gray, and the disease spots often crack. When it is wet, the disease spot overflows the bacterial pus on the disease part of the melon strips, and the disease spots spread to the inside of the melon strips, changing color along the vascular bundles and extending all the way to the seeds, causing the seeds to carry bacteria. The diseased melon rotted in the later stage, with a bad smell, and the young melons often rotted and fell early after being killed. Germs in the soil spread in the fields through irrigation, wind and rain, airflow, insects and farming operations. The bacteria invaded the host by stomata, wounds and water holes. The suitable temperature for the disease is 18-26 ℃, and the relative humidity is more than 75%. The greater the humidity is, the more serious the disease is, and the disease is easy to spread after the storm. The land with low-lying terrain, poor drainage, continuous cropping, too much nitrogen fertilizer, insufficient potash fertilizer and over-dense planting are all serious diseases.

[prevention and treatment methods] at the initial stage of the disease, spray 5000 times of neophymycin, or 30% copper succinate (DT sterilization) wettable powder 500 times, or 77% kill wettable powder 400 times, or 47% plus Ruinong wettable powder 600,800 times, the above agents can be used alternately, once every 7 days, 3 times in a row. Excessive use of copper preparation is easy to cause drug damage, generally no more than 3 times. Spray should be carefully and thoughtfully sprayed to the front and back of the leaves, which can improve the control effect.

6. Root-knot nematode

[symptoms] mainly damage the roots. After the root is damaged, there are many lateral roots, and spherical or conical nodules of different sizes are formed at the root tip, sometimes in series, initially white and soft, then brown to dark brown, and sometimes cracked on the surface. The aboveground part of the injured plant was dysplastic, the leaves were yellow, wilted and died early in the day, so it was easy to be mistaken for a wilt plant. The optimum temperature for the development of root-knot nematode was 25-30 ℃. It took 25-30 days for the first generation to reproduce at 27 ℃. The larvae stopped active at 10 ℃ and died after 10 minutes at 55 ℃. Nematodes are mostly active in 20 cm deep soil layer, especially in 3-10 cm soil layer. Nematodes spread by soil, diseased seedlings, irrigation water, agricultural operations and so on. Under the conditions of high topography, loose soil and low salinity, it is suitable for nematode activity, which is beneficial to the disease, and the disease is serious in sandy land and continuous cropping land. Under the condition of no host, nematodes can survive in soil for 1 year.

[control methods] soil disinfection: before planting, 80 kg of lime nitrogen was applied in combination with deep ploughing mu, and the soil was disinfected with 1.8% Zongmike EC 1-1.5 ml per square meter with 6 liters of water, or 4-6 kg per mu of Milol 3% granule, mixed with 50 kg dry fine soil; during the growing period, 1.8% Zongmike EC was used to irrigate the root 1 000-1 500 times twice, with an interval of 10-15 days. After harvest, the diseased and residual plants are thoroughly removed in the field, and concentrated burning or deep burial can be used for retting fertilizer. In addition, the application of two tons of biogas residue per mu can effectively control root-knot nematode. Where there are conditions, a crop of rice can be planted at the end of vegetable harvest.

7. Whitefly

Powdery mildew has various feeding habits and can harm a variety of vegetables. Mainly to nymphs, concentrated on the back of cucumber leaves to absorb juice, resulting in leaf discoloration, yellowing, wilting, serious plant death. During the damage, it also secretes dense dew, pollutes the leaves, causes fungal infection, affects plant photosynthesis, and seriously affects yield and quality.

[prevention and control methods]

A, try to avoid mixed planting, especially cucumbers, tomatoes and beans. It is also an effective method to adjust the production stubble, that is, the vegetables with less damage caused by white whitefly such as celery and sweet pepper are arranged in the first crop, and cucumbers and tomatoes are planted in the next crop.

B. the old nymphs are mostly distributed in the lower leaves, and the old leaves are removed and burned. Setting yellow board in greenhouse can effectively control whitefly.

C. 1% deltamethrin or 2.5% fenvalerate (fenvalerate) oils are atomized into droplets with a knapsack motor smoker, and the effect of killing adults is good when suspended in the air.

D, 25% buprofezin (buprofezin) wettable powder or 2000 deltamethrin or 20% fenvalerate EC can be sprayed every 6-7 days for 3 consecutive times. It can also be fumigated with aerosol for 2-3 times in a row.