Complete collection of detailed information about seedling raising

Yùmiáo means to cultivate seedlings. The original intention is to cultivate seedlings in nurseries, hotbeds or greenhouses and transplant them into the land for planting. It can also refer to the stage when all kinds of creatures are artificially protected at a very young age until they can survive independently. As the saying goes, "Miao Zhuang gets half the harvest". Seedling raising is a labor-intensive, time-consuming and high-tech job.

Basic Introduction Chinese Name: Seedling Pinyin: yùmiáo Interpretation: Seedling characteristics: Basic information about seedling facilities, sowing articles, selection of plugs, selection and filling of substrates, punching and sowing, uniform coverage, daily management, water management, fertilizers and nutrients, pest control and plant type control. Through investigation, Zhengzhou Zhonglian Chemical technicians found that in the past, due to poor equipment and natural conditions, Moreover, the traditional seedling raising technology only depends on experience, and there are many technical misunderstandings, especially the seedling raising based on experience is difficult to master and popularize. Therefore, we suggest adopting centralized seedling raising and transplanting, which has many advantages, such as: 1, convenient management in the early stage of centralized seedling raising, especially pest control; 2, seedlings are not delayed after planting, and the plants grow neatly; 3. The nutrient formula of the nursery substrate is reasonable, and the cultivated Miao Zhuang has developed roots, fast growth, good flower bud differentiation and increased yield, which can be put on the market early; 4, the special substrate for seedling cultivation is sterile and nontoxic, thus reducing the occurrence of soil-borne diseases; 5. Plastic tray seedling is convenient to transport, saving labor, time and effort. Nursery facilities 1, nursery site selection The nursery site selection should be in a place with convenient transportation, flat and open land, no water, no water and no electricity, and the environmental conditions of the nursery site must meet the requirements of pollution-free production. At the same time, it can meet the needs of building facilities such as seedling shed according to the seedling scale. 2. The infrastructure adopts standard steel shed, generally 6m wide, 1.8m high and 20m long. If economic conditions do not allow, bamboo scaffolding can also be used. The size of the seedling shed can be adjusted according to the size of the seedlings. According to the weather and the needs of the seedling raising process, plastic film and sunshade net are selected to cover the seedling raising shed. Covering materials in greenhouses mainly include film, sunshade net and insect-proof net. 3. Pepper, persimmon and eggplant were selected as seedling trays with 72 holes and 54×28cm floppy disks. The upper diameter of each hole is 3.8 cm, the bottom is 2.0 cm, and the depth of each hole is 4.6 cm. Bitter gourd, pumpkin, green (yellow) melon, melon and wax gourd: choose 50 holes, 54×28 cm floppy disk, each hole has a top diameter of 5 cm, a bottom diameter of 2.2 cm and a hole depth of 5 cm. In addition, the used plug may be infected with some pathogenic bacteria and eggs, so it must be cleaned and disinfected. The method is to remove the residual matrix in the seedling tray, rinse it with clear water, dry it, and soak it in carbendazim 500 times solution 12 hours or potassium permanganate 1000 times solution for 30 minutes for disinfection. Formaldehyde solution and bleaching powder solution can also be used for disinfection. Sterile plugs must be thoroughly cleaned and dried with clean water before use. 4. Preparation of nursery substrate The nursery substrate is coconut chaff after high-temperature composting: sterilized topsoil (fields where melons and vegetables have not been planted for 2-3 years): organic fertilizer (organic fertilizer must be a product conforming to the industry standard NY525, with an organic matter content of not less than 30% or chicken manure, cow manure and pig manure after high-temperature composting), and fully stirred according to the volume ratio of 70: 27: 3. Put the substrate into the seedling tray of rootstock, spray 50% Julixing activated rooting dispersant or 600-800 times carbendazim in the seedling tray, and require that the seedling substrate be thoroughly poured. You can also choose to buy special substrates for seedling raising. The price of seedling substrate is about: pumpkin 1 yuan/plant, pepper and tomato, eggplant 0.7 yuan/plant. The seedbed is placed in a standard steel greenhouse. There can be two seedbeds, left and right, with a work lane in the middle. The specifications of the seedbed are: the width of the seedbed is 2 meters, each bed is longitudinally arranged with 6 rows of seedling trays, and the working track between the two beds is 0.6 meters wide and 0.7 meters away from both sides of the greenhouse ... The length of the seedbed depends on the specific situation of the greenhouse. Multi-span greenhouse can be arranged according to the above method. When raising seedlings, spread an intact film on the surface of the seedbed to keep moisture and prevent the seedlings from stringing roots and the excess water and nutrient solution from infiltrating into the ground. According to the above seedbed settings, about 2,600 floppy disks can be placed in each mu (667m2) seedshed. The seedling raising time is about one month, and the seedling raising place can provide 50-80 mu of pepper, 100 mu of small tomato and 80- 100 mu of eggplant for field planting at one time. Melon 80 ~ 100 mu, cucumber 40 ~ 50 mu, wax gourd 200 mu, pumpkin and bitter gourd 220 ~ 250 mu. 6. Fertilization in nutrient solution pool is set in the form of spraying. The nutrient solution pool can be built according to local conditions. According to the seedbed area, spray 1- 1.5 kg/㎡. In the sowing process, select the appropriate plug, select a good substrate, fill the substrate correctly, punch holes, sow the seeds evenly to the center of the holes, cover the seeds evenly and water them properly. This completed the first step of industrialized plug seedling raising. The smaller the plug, the more sensitive the plug seedlings are to the changes of humidity, nutrients, oxygen, PH value and EC value in the soil. The deeper the hole, the more air in the matrix, which is beneficial to air permeability, salt dissolution and air permeability, and is beneficial to root growth. The substrate must be at least 5 mm deep to have gravity, so that the water in the substrate can seep down. The deeper the air enters the hole, the more oxygen it contains. The shape of the hole should be square and inverted trapezoid, which is beneficial to guide the root system to extend downward, instead of the root system winding on the inner wall like in a circular or vertical hole. The deeper holes provide more favorable conditions for the drainage and ventilation of the substrate. Some trays also have ventilation holes between holes, so that air can flow between plants. Dry leaves, reduce diseases, dry evenly, and ensure the uniform growth of the whole plant. The color of the plug will also affect the temperature of the plant roots. Generally, black cuttings are selected in winter and spring, because black cuttings can absorb more solar energy and raise the temperature of roots. In summer or early autumn, change to silver-gray inserts to reflect more light and avoid excessive root temperature. However, the light transmittance of white cork is generally high, which will affect the growth of root system, so white cork is rarely chosen. Of course, white foam plugs can be an exception. After thorough cleaning and disinfection, the plug can be reused. It is suggested to use safer quaternary ammonium salt disinfectant, which can also be used to sterilize and kill algae in irrigation system to avoid the breeding of bacteria and moss. It is not recommended to use bleaching powder or chlorine for disinfection, because chlorine will react with the plastic in the hole plate and produce toxic substances. Selection of substrate and selection of filling substrate: A good substrate should have the following characteristics: ideal water holding capacity; Good drainage ability and ventilation ability; Easy to get wet again; Good porosity and uniform pore distribution; The vascular bundle structure is stable, with less dust; The PH value is appropriate, 5.5-6.5; It contains a proper amount of nutrients, which can ensure the nutritional needs of cotyledons before unfolding; For very low salt level, EC should be less than 0.7 (1: 2 dilution method); The size of matrix particles is uniform; No pests and weeds; The quality of each batch of substrates is consistent. Because vermiculite with smaller particles is used to increase the water retention of the matrix rather than the porosity. In order to increase the drainage and permeability of peat matrix, perlite is added instead of vermiculite. On the contrary, if you want to increase the water retention capacity, you can add a certain amount of vermiculite particles.

Pay attention to the following points: Although imported peat is an ideal source of raw materials for seedling culture, it is expensive and the resources are non-renewable, so western countries gradually switch to processed coconut shell crushed materials as the source of substrate, and the effect is equally good. They call it coconut peat. 1, the matrix should be fully wetted before filling, generally 60% is appropriate. Hold a matrix in your hand and no water will come out. If you let go of your hand, it will form a ball, but if you touch it gently, the matrix will spread out. If it is too dry, the substrate will collapse after watering in the future, resulting in poor ventilation and poor root development. 2, the filling degree of each hole should be uniform, otherwise the hole with less base will dry quickly, which will make the water management unbalanced; 3. The matrix of holes for sowing big seeds such as melons should not be too full; 4. Avoid squeezing the substrate, otherwise it will affect the permeability and drying speed of the substrate, and because the substrate is pressed too tightly, the seeds will rebound, resulting in different shades when the seeds finally germinate. Precautions for drilling and sowing: the drilling depth should be consistent to ensure the same sowing depth. Generally, the bigger the seed, the deeper the sowing depth. It is necessary to cover several common vegetable seeds evenly in the dark to germinate smoothly, so it is also important to choose suitable mulch. The selection of plastic film should consider several aspects: it can improve the humidity around the seeds, maintain good air permeability and provide enough oxygen for the seeds. It is suggested to use large particles of vermiculite as mulch. Perlite mulch is easy to breed moss. 5. Water first after sowing: There are two schemes: when the seeds germinate on the seedbed, water a little first, and then water again after all the plugs are moved to the seedbed. If the seeds are in the germination room or simple germination room (after the grass is covered with water), they should be watered before entering the germination room. It is recommended to use an atomizing nozzle or a nozzle with water mist. After the daily management sowing work is completed, it will enter the daily management stage. This paper expounds from four aspects: watering, fertilization, pest control and plant type control. The most important work of water management in seedling production is water management. But in the actual work process, it is often done by people with little experience. Watering at the wrong time or in the wrong way will seriously affect the production of plug seedlings. Never let the plug seedlings dry completely; On the other hand, the water in the substrate is too saturated, which will lead to root hypoxia (0-2%). Usually, cotyledon spreading is the dividing line of water management in plug seedling production. The water management before cotyledon unfolding is relatively simple, that is, to keep the substrate in the lower cavity moist all the time. Only the dry-wet alternation of the substrate at the upper part of the hole can be controlled. However, after cotyledons are unfolded, it is necessary to control the humidity of the lower part of the cavity substrate according to environmental changes and plant growth. Before watering, you can dig a part of the substrate to see if there is a certain humidity under it. Of course, estimating the plug weight and judging the humidity of the substrate is an ideal test method. The premise is that you have some experience and know the weight of plugs at different humidity levels. You can also lift the plug to see if the substrate at the bottom of the plug is dry, so as to decide whether to replenish water. By watering, 10% water can seep out of the plug, and then it can enter the wet cycle. When applying fertilizer or filling medicine, be sure to water it thoroughly. When pouring water, just pour it until the water flows through the plug. The water in the substrate is lost through evaporation and root water absorption, the former plays a major role before cotyledons unfold; After the cotyledons are unfolded, the roots with transpiration play a major role in water absorption. So at this time, we should judge how to water according to the influence of environmental climate change on plant transpiration. For example, in the following cases, it is more appropriate for water to reach only half a hole: 1, the weather turns from sunny to cloudy, cold, or the humidity in the greenhouse is particularly high. Water evaporation is slow, transpiration is low, and blockage is not easy to dry. 2. There is a certain humidity in the lower part of the hole. 3. Fertilize the seedlings the next day. When the weather is hot, the seedlings can effectively control the excessive growth of seedlings by using the semi-flow technology. Too many times of watering, plants will grow in vain, reduce the permeability of the substrate, cause damage to the root system, and thus easily infected with germs. Watering in the greenhouse is the most important task and should not be operated by inexperienced people. Watering needs more experience accumulated by workers, not written or oral knowledge. Matters needing attention in water quality: PH, alkalinity and EC. The PH value of production water should be in the range of 5.0-6.5, because most nutrients and pesticides are effective in this range, and beyond this range, the effectiveness will be greatly reduced. The alkalinity of water represents its buffering capacity. If the alkalinity is too low, the PH value of the substrate will fluctuate greatly with the pH value of the fertilizer. This may lead to the lack or poisoning of some trace elements. If the alkalinity is too high, it will easily lead to the lack of some trace elements, such as iron and boron. EC value, generally, the EC value of irrigation water without fertilization should be lower than 1.0ms/cm, which is suitable for production. High concentration of soluble salt will reduce germination rate, damage roots and root hairs, and burn leaves. Don't let the substrate in the plug be too dry, otherwise it will increase the salt concentration around the root system by 3-4 times. Generally speaking, the alkalinity of soft water with low calcium and magnesium content is very low, so it is necessary to use alkaline fertilizer containing calcium and magnesium, which can increase its buffering capacity. If the alkalinity is high, there is no need to use this fertilizer, and attention should be paid to adjusting it with acid fertilizer. In particular, in some northern areas, when the rainy season comes in summer, the hardness, PH value and EC value of groundwater will be significantly higher than usual, which will easily reduce the utilization rate of phosphate fertilizer and lead to the occurrence of trace element deficiency such as iron deficiency, especially when mancozeb and other manganese-containing broad-spectrum fungicides are used, more attention should be paid to the occurrence and prevention of iron deficiency. Because iron is the easiest to compete with manganese, when the substrate is wet, the temperature is lower than 15℃ and the PH value is higher than 6.5, iron will not be effectively absorbed by the root system. Selection of fertilizer and nutrient fertilizer for seedling raising Generally speaking, a good commercial seedling raising substrate can provide all the nutrients needed before cotyledons are fully unfolded. Because the plug container is small, leaching is fast, the PH value of the substrate changes rapidly, and salt is easy to accumulate, which hurts the root system of seedlings. Therefore, it is necessary to choose high-quality and stable water-soluble fertilizer as a nutritional supplement after cotyledons are fully unfolded. There are two factors to consider when choosing fertilizer: 1, and there are three kinds of nitrogen fertilizer, which have different effects on plant growth. 2. Choose different fertilizer formulas according to the environmental conditions and climate in different regions.

The adverse effects of high humidity on seedlings are: too long internodes, too thin stem segments, less branches and less roots. At the same time, under the condition of high humidity, the absorption of calcium by roots will be reduced, because of the influence of environmental humidity on vegetable seedlings: under the condition of high humidity and poor ventilation, diseases are easily induced. On the other hand, if the environmental humidity is too low, the transpiration of plants will be too strong in the high temperature and strong light environment, and the water absorbed by plants through roots will not be enough to supplement the water lost by leaves, so the stomata will be closed to protect plants from excessive water loss. Because the stomata are closed, carbon dioxide can't enter the plant, so photosynthesis will stop and plants will stop growing. Low humidity accelerated the transpiration of plug seedlings and promoted the absorption of calcium and magnesium by plants. In a state of water shortage, the stomata will close. Stop growing, so low humidity will make the stem stronger, more resistant to stress and the root system develop better. Therefore, we should be alert to the symptoms of calcium and magnesium deficiency on cloudy days and supplement them with foliar leaves in time. The normal leaf color should be pure green. If the lower leaves turn yellow, it means that the plant nutrients are not enough or the root system is injured. Dark green leaves indicate excessive ammonium fertilizer. Light green leaves indicate nitrogen deficiency, ammonium poisoning or magnesium deficiency. The time of pest control is short, so it is rarely threatened by pests and diseases. However, due to the dense growth and large quantity, if the environment is not well controlled or managed, diseases and pests will also occur. Plant type control For commercial seedling producers, neat and robust plug seedlings are the same goal. Many breeders have made great efforts to this end. The most common practice is to manually move seedlings once in the middle of seedling raising to solve the problem of orderly movement. If you refer to our suggestions in your previous work (select highly consistent seeds and substrates, fill them correctly, punch holes evenly, sow seeds evenly and water them evenly), then the labor of this work can be greatly reduced. In order to realize the short and strong seedlings, many breeders will choose to use chemical growth regulators to adjust the height of plants in production practice. We want to remind you that this is an efficient but dangerous practice. First of all, we don't approve of using chemical hormones in food. Repeated use of hormones has many sequelae, which requires certain methods of use and environmental conditions. For example, chlormequat chloride can only slowly enter the leaves when they are wet, so it is best to use it at night. Don't use hormones when plants are short of water, otherwise it is easy to produce phytotoxicity. This paper introduces several methods to control plant height other than hormones: 1 and negative temperature difference between day and night (the temperature at night is 3-6 degrees higher than that during the day for more than 3 hours), which is very effective to control plant height. The production method is to reduce the temperature as much as possible for three or four hours before and after sunrise. 2. Reducing the temperature, moisture or relative humidity of the environment, replacing ammonium nitrogen fertilizer and urea nitrogen fertilizer with nitrate nitrogen fertilizer, or reducing the amount of fertilizer as a whole and increasing the illumination can inhibit the growth of plants. 3. There are some mechanical methods, such as poking, vibrating and increasing airflow, which can inhibit the growth of plants. For example, pulling tomato plants several times a day can obviously reduce the height of plants, which is more important than avoiding damaging leaves, and crops with easily injured leaves such as peppers are not suitable for this. Of course, if you use hormones, especially chlormequat chloride, it will lead to drug damage. In addition to spraying hormones with opposite effects to alleviate drug effects and appropriately increase water and ammonium nitrogen to promote growth, we can try spraying seaweed essence on leaves, which will get obvious results. If the roots grow long and slender on the outside of the substrate and the ground of the plug, they are usually called water roots, indicating that the substrate is airtight because of excessive watering. Even if root hair is produced, it will be lost under the condition of high salt and drought. The shedding of root hairs will hinder the growth of seedlings, prolong the slow seedling stage after transplanting, easily infect bacteria and cause root rot.