Problems that should be paid attention to during the process of vegetable seedling raising

Vegetable seedlings are the key link in greenhouse vegetable cultivation. They are related to the health and high yield of crops. Some experts have summarized past experience. At present, there are some problems in seedling cultivation. If they are not improved, it will affect the healthy development of greenhouse vegetable production.

First, water management

Moisture management is a very important task and should be done by the most experienced managers. Many people think that watering is a simple matter. In fact, there are many problems in management.

1. The quality of the nozzle is poor, resulting in uneven watering.

Factoryized nursery and watering is the most important management link. The bad nozzles are easy to block, the watering is uneven, and some places drip, causing some places in the tray to dry, and some places have too much humidity. It is very important to choose a good nozzle. Arrange the spacing reasonably, check and clean the filter to prevent blockage.

2, pay attention to watering time, to prevent leaf surface condensation.

In high-temperature nursery in summer, it is necessary to keep the leaves dry. If there is a water film on the leaves at night, it will cause disease. Try not to water after 5 pm. When opening the fan after five o'clock, try not to open the damp curtain again, especially at night, to prevent excessive humidity at night. No water is given at noon to prevent seedlings from being stimulated by cold water and affecting growth.

3. Too much watering causes the stems and leaves to grow.

Prevent water shortage in summer, often watering too much, green moss on the surface of the substrate, roots and stems are easy to induce disease; the aboveground part is prosperous, the root system is relatively poor, this seedling looks strong, planted into the field, slow seedling slow, weak . The correct one should be to see the wet.

Second, the germination rate

The low germination rate of the seeds causes the seedlings to be uneven. The seedlings of the trays must be selected from the seeds with high germination rate, good buds and uniform germination. The general bud rate is above 95%. Low bud rate wastes manpower and material resources. Increase the cost of seedlings.

The reason for the low seed germination rate is related to the following factors in addition to the seed itself.

1. The seeds are suffocated at high temperature and do not germinate.

Seedlings are grown in the hot season. After sowing, the internal temperature of the matrix will reach 50 °C. Under this condition, the seeds will cause suffocation and death. The internal temperature of the substrate should be reduced, such as shading, selection of cloudy day sowing, etc. After high-temperature sowing in summer, it is generally necessary to set up a two-layer shade net before 9:00-17:00. Make the daytime temperature at 27~32°C, and reduce the night temperature as much as possible. After covering the shade net, it is still necessary to keep the wind out to prevent steaming. After the buds are released, the sunshade net can be gradually removed, and the air vents should be ventilated at night to cultivate strong seedlings by widening the temperature difference.

2. It is best to cover the meteorite after sowing.

There are two methods for covering the seedbed after seeding, one is to use vermiculite, and the other is to use the original matrix. Nowadays, many nursery companies are covering the original substrate after sowing. This method of covering has some influence on the emergence of the seedlings. The correct method of covering is covered with coarse vermiculite. Covering vermiculite is not easy to cause scouring when watering. Secondly, vermiculite itself is pyrolyzed, it is not easy to induce root-based diseases. Third, the water-holding characteristics of vermiculite and matrix are different, and it is not easy to cause matrix water to rise from capillary. The role of forming the surface of the tray is dry and the interior is wet. The particles covering the substrate should be suitably thick.

3, summer vegetable seedlings

Covering the mulch film is dangerous. In order to reduce the evaporation of the substrate moisture after sowing, the method of covering the mulch is adopted. After the summer sowing, it is very risky to cover the mulch on the tray. First, after the mulch is covered, the mulch and the tray form a closed space, which causes high temperature to cause boring. Especially in the greenhouse, if the substrate is not very full, after the mulch is overlaid, it is equivalent to giving it a second film, and in the hot summer season, the temperature in the tray can reach 50 °C. If you do not pay attention to the cooling of the seedbed, the temperature and humidity are not well grasped, and the boring phenomenon is very likely to occur. Second, if the mulch film cannot be withdrawn in time, the seed in the tray will be scalded and easily smashed after the soil is unearthed. The seedlings that have just been arched out of the nutrient soil are very delicate, and their heat resistance is very poor. It is prone to wilting at high temperatures, and it is easy to burn the growth point when it encounters a film with a high temperature under direct sunlight.

Third, the use of the substrate

1. Understand the composition of the matrix and understand the basic nutrient content of the matrix.

In addition, the physical and chemical properties of each batch of the substrate are somewhat changed. Therefore, after the purchase of a batch of substrates, the basic physical and chemical properties of the matrix should be examined. In particular, the conductivity, water holding capacity and aeration characteristics of the matrix should be understood to control the moisture and nutrient management of the seedlings. Provide evidence.

2. If it is a self-supporting substrate, pay attention to the proportion of different materials, trial and error, mainly based on grass charcoal, choose a low-grade peat with good texture, the ratio should not be lower than 40% when mixed with inorganic materials; The main one is to ensure that the degree of maturity is appropriate. The second is to pay attention to the size of the particles. Generally, the sieve with a diameter of 5 mm can be used.

Fourth, the reuse of the plug

The trays must be disinfected before repeated use, to avoid the pathogens of the previous seedlings brought into the next layer. The disinfection method is generally to use 40% formalin 100 times solution to soak the seedling tray for 15~20min, and the film is sealed for 7 days and then uncovered. Rinse with water and use. Some plug seedlings themselves have root pests and diseases, such as root-knot nematodes. If such seedlings are planted in the ground, they will introduce nematodes. Therefore, in the transportation and purchase of commercial seedlings, attention must be paid to the disease problem of the seedlings themselves.

5. Improper laying of the seedbed causes the roots to be tied down.

Plug seedlings are one of the root-preserving seedlings. One of the advantages is to avoid damage to the seedling roots during colonization. However, many seedling plants are now improperly placed in the seedling bed, causing a large number of roots to protrude from the bottom of the tray. The roots of the seedlings are greatly damaged when planted. The roots have the characteristics of water-like properties. If the seedling plate is placed directly on the surface or on the object that can keep the water (such as plastic film, felt cloth, etc. at the bottom of the tray), it will cause a large number of roots to protrude from the seedling plate, which will cause a lot of damage to the roots in the future. . The correct way to prevent the roots from sticking out of the tray is to place the tray on the seedbed, or place the tray on the floor cloth.

6. Improper transportation

The loss of seedling quality has a great impact on the quality of seedlings, especially in the hot and cold seasons.

Management of seedlings before high temperature transportation in summer: 1. Seedlings must be refining seedlings before transportation. There should be no water drops and dew on the leaves before the baskets, while maintaining the proper humidity of the substrate. This needs to be determined by reasonable watering and opening of the fan to reduce the humidity in the shed; before the seedlings are kept at the lowest temperature in the day, that is, in the morning, the inside of the seedlings is not easy to heat up after loading.

Summer nursery is best to raise seedlings in the cloudy sky. 2, transport vehicles: to choose a ventilated vehicle, seedling baskets should also choose to breathe. The sunshade net is covered above during transportation. Also take measures to prevent rain. 3. Management after the seedlings are transported to the base: the land is sorted out in advance, and the seedlings are transferred to the base and hurry to transplant. After the seedlings arrive at the base, the seed baskets are transported from the car as soon as possible, placed in a cool and ventilated place, and the upper part is covered with a sunshade net. In one day, the seedlings will not be short of water, and there is no need to replenish water. It is best not to leave more than 2 days.

The above is all the contents of today. Welcome everyone to continue to pay attention to Hui Nong.com and learn more about agricultural technology.

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