When will cucumbers be planted?

Cucumbers like warmth and are not resistant to cold, so cucumbers are widely distributed in southern China and are one of the main greenhouse products. Because of the different planting time, they are divided into spring cucumbers and autumn cucumbers. The following editor will introduce the planting time of spring cucumbers and autumn cucumbers.

Planting time of Spring Cucumber

Spring cucumber refers to the cucumber that is raised in winter and harvested in spring. Let's take a look at the sowing time and planting time of spring cucumber:

1. The sowing time of spring cucumber: the sowing time of spring cucumber is determined according to the planting date, the suitable calendar seedling age is 40-50 days, and the physiological seedling age is four leaves. If the seedling age is calculated according to the calendar, the seeds will be sown 40-50 days before planting. The age of physiological seedlings is related to the method of raising seedlings. It takes 50-55 days to raise seedlings in sunny beds or solar greenhouse, 45-50 days in heating greenhouse and 45 days in electric hotline greenhouse. Therefore, the sowing time is also different with different seedling raising methods. Practice has proved that rapid seedling raising not only saves time, but also emerges quickly and thrives, and the early yield is high. Where there are conditions, try to use rapid seedling breeding.

2. The planting time of spring cucumber: the planting time of spring yellow claw is after the local late frost, and the ten-day average temperature is more than 18t. Beijing, Tianjin and Shijiazhuang are generally planted after late April. In order to slow down the seedlings quickly, choose sunny days to plant seedlings, do not plant in cloudy or windy days. The planting density is mainly determined by the characteristics of the variety.

Planting time of autumn cucumber

The cultivation of autumn cucumber is only in the frost area, which refers to the end of harvest before the first frost, while in the frost-free area all the year round, the cucumber is listed in summer cucumber seedling pulling and autumn. The growth period of autumn cucumber is only 80-90 days, and it can be directly cultivated or transplanted. production in open field or greenhouse.

Autumn cucumber is generally sown about 70 days before Frosts Descent, and seedling transplanting can be carried out 7-10 days in advance. Because the seedling stage and early growth stage are in the high temperature and rainy season, the diseases and insect pests of autumn cucumber are serious and the yield is low.

Growth habits of Cucumber

1. Temperature: cucumbers like warmth and are not resistant to cold. The suitable temperature for fertility is 10-32 ℃. Generally, the growth is the best at 25: 32 ℃ in daytime and 15: 18 ℃ at night, the most suitable ground temperature is 20: 25 ℃, and the lowest is about 15 ℃. The most suitable temperature difference between day and night is 10: 15 ℃. The photosynthesis of cucumber was poor at 35 ℃, high temperature obstacle appeared at 45 ℃, and the cucumber was frozen to death at-20 ℃. If the seedlings were refined at low temperature, they could withstand the low temperature of 3 ℃.

2. Light: the South China type variety is more sensitive to short day sunshine, while the North China type variety is not strict on the length of sunshine, and has become a sunshine neutral plant, with a light saturation point of 55000 lux and a light compensation point of 1500 lux. most varieties grow well under the condition of 8-11 hours of short-day sunshine.

3. Moisture: high yield and high water demand of cucumber. The suitable soil moisture is 60-90%. The moisture in the seedling stage should not be too much, and the soil moisture is 60-70%. In the result period, sufficient water must be supplied, and the soil moisture should be 80-90%. The suitable air relative humidity of cucumber is 60-90%. If the air relative humidity is too high, it is easy to get sick, resulting in a reduction in production.

4. Soil: cucumbers prefer wet but not waterlogging, fertilizer but not fertilizer, so it is appropriate to choose fertile soil rich in organic matter. The soil between pH 5.5 and 7.2 is generally preferred, but the pH value of 6.5 is the best.

OK, the above is the planting time of spring cucumber and autumn cucumber. Let's take a look at the common diseases and insect pests and their control techniques in the planting process of cucumber.

Pest control

1. Downy mildew

[symptoms] Downy mildew is a fungal disease, which occurs in the middle and upper leaves of cucumber. The following key 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 they have these three points, they 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 control methods.

[prevention and control methods] Anke, Prike, Miike, Frost Urea Manganese Zinc, Yikuangjing, Jinreidi and Amisida can be selected. 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.

[prevention and control methods] 10% Sukeling smoke agent or 45% chlorothalonil smoke scavenger can be used in the early stage of the disease in the protected area, 250 grams per mu each time, fumigating 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] at first, small round white powdery mildew spots grew on the front or back of the lower leaves, gradually expanded, 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.

[control methods] powdery mildew bacteria are particularly sensitive to "sulfur". Before planting, fumigation is ignited with 1.8 kg sulfur powder per mu plus sawdust or other combustion aids, which can kill powdery mildew bacteria and fumigate again every 3 days. 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 disease spot was slightly sunken on the cotyledons in the seedling stage, 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

The symptoms are mainly harmful to the root. 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, 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 was mixed with 50 kg dry fine soil; during the growing period, 1.8% Zongmike EC was used to irrigate the root twice at 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

[symptoms] the feeding habits of powdery mildew are very miscellaneous, which 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.

[control methods] try to avoid mixed planting, especially cucumbers, tomatoes and kidney 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. The old nymphs are mostly distributed in the lower leaves, which are removed and burned. Setting yellow board in greenhouse can effectively control whitefly. 1% deltamethrin or 2.5% fenvalerate (fenvalerate) oil is atomized into droplets with a knapsack motor smoker, which is very effective in killing adults when suspended in the air. You can use 25% buprofezin (buprofezin) wettable powder or spray 2000 times of deltamethrin or 20% fenvalerate EC every 6-7 days for 3 consecutive times. It can also be fumigated with aerosol for 2-3 times in a row.