[China Agricultural Machinery Industry News] The phenomenon of poor production and production has occurred every year. In fact, the reasons for the bad emergence of seedlings are more complicated, sometimes in terms of varieties or seeds, and more often with soil, climatic conditions, farming. Or the quality of seeding, sowing date, pests and other factors may be caused by a single factor, or it may be the result of a combination of several factors. Specifically, what is the reason for the specific analysis based on the results of the field survey, to find the relevant factors affecting the emergence of seedlings.
What is the reason why corn is not good?
1. Influence of genetic characteristics of varieties
Some varieties have short bud sheaths and weak top soil. Even if they are planted in the depth of conventional sowing of most varieties, it is difficult to emerge, not to mention that the seeding is too deep. This problem can be avoided by knowing the characteristics of the variety at the time of purchase.
2, the impact of seed quality
First, the seed germination rate is not high. The germination rate of qualified seeds in the state is not less than 85%. When the seed dehydration stage suffers from frost, improper storage conditions, and storage expires, the germination rate will be significantly reduced.
Second, the germination is poor, the top soil is weak, and the emergence is not good. Third, the seeds are mixed with old seeds with low germination rate. When the seed quality is poor due to poor seed quality, the emergence of the same batch of seeds in different plots is consistent, otherwise there may be other reasons.
3. Influence of soil conditions
In saline-alkali soil, due to the high salt concentration in the soil solution, the osmotic pressure is high and the seeds are difficult to absorb and germinate. Even if it is germinated, the young root buds are limited by the tolerance of salt, and there is a phenomenon of reverse osmosis, which causes physiological dehydration, which is wilted before being unearthed and seriously affects emergence.
Soil is sticky, and post-sowing rainfall is likely to cause soil compaction, which affects the emergence of young shoots.
Maize seed germination needs to absorb 50% of the dry weight of the seed. The soil holding capacity of the cultivated layer is about 60%, which is conducive to germination. The soil moisture content is too low, the moisture is not good, and the seed is not enough to absorb the seedlings. Spring drought in dryland occurs frequently, so soil moisture in spring maize area is often the key factor affecting emergence.
Excessive moisture prevents the seeds from breathing normally and is susceptible to mold attack, causing mildew in the seeds.
4. Effects of farming and sowing quality
The whole land is extensive, the soil is sloppy, the soil runs through the wind, the water is insufficient, and the seeds sowed cannot be in close contact with the soil. The land is not flat and the sensation is uneven. It also has a great influence on the seed germination and sprouting. The improper seeding depth is also an important reason for the emergence of seedlings. The sowing is too shallow and the seeds fall on the dry soil. The broadcast is too deep, the buds are difficult to top soil; the soil is not flat, the depth of the machine is different, the shallow seeds are not broadcast on the wet soil, and the stalks are not conducive to emergence, and there is no decomposed roots in the soil. Earthworms, straw, and overhead soil affect the quality of sowing, and the mulch film that varies in the depth of the soil, or hinder the root system. Or affecting the topsoil of the young shoots, this is another reason that affects emergence.
5. Impact of sowing date and meteorological conditions
For spring maize, the sowing date is actually a problem of high temperature and low temperature. The temperature of the ground is generally affected by the temperature. There is also a difference in the temperature of the soil under different soil quality, topography and coverage. In sandy loam and sunny slopes, the temperature rises rapidly; while in the wetlands, clay fields, shady slopes, and straw cover, the temperature rises slowly. The seeds are germinated and germinated, and the seedlings are excavated to require suitable soil temperature. The low temperature of the germination of the corn seeds is 6-7 ° C. At this time, the germination takes a long time and is prone to mildew.
When the soil temperature of the tillage layer is 10-12 °C, the seed germination is faster and tidy! However, the radicle and germ growth are slow, and it usually takes more than 13 days to unearth. This temperature is used as the low temperature indicator for sowing. When it reaches 18-20 °C, it takes only 7-8 days to emerge, so sowing too early is not good for emergence. After sowing, continuous low temperature, soil temperature rise, and soil compaction caused by storms after sowing, also affecting emergence.
6. Impact of pests, mechanical injuries and phytotoxicity
Degranulation, the seeds are mechanically damaged during processing, and the embryos are damaged by feeding and pests during storage. After sowing, the seeds are prone to mildew. When the seeds are mixed with seeds or coated, the amount of overdose or mixed seeds is uneven! It may cause phytotoxicity. The phytotoxic seeds may not germinate, or the growth of the buds may be inhibited, the deformed bones may be deformed, and the tops are not unearthed.
Excessive or uneven fertilization during sowing, or direct contact between chemical fertilizer and seeds, can burn out young shoots is also a remedy.
Underground pests such as cockroaches, cockroaches, etc. can feed seeds in the soil, bite off the young buds, and the squirrels can tunnel in the tillage layer and eat seedling seedlings, which can cause seedling ridges and stagnation at low temperature and high humidity after emergence. Under the conditions, seedlings that are not resistant to disease are susceptible to attack by diseased bacteria and can cause blasts.
When seed damage and pesticide damage cause poor emergence, often the same batch of seeds will occur. Fertilizer burns and pests and diseases may differ depending on the planting plot.
Corn seed is a living organism that is once again planted in a larger and more complex ecosystem. In addition to the genetic traits and seed quality of the seed itself, it is also affected by soil, climate, farming, cultivation, and disease. The effects of various adverse conditions such as pest damage.
There are natural factors as well as human factors. These factors alone or in combination affect several factors. Through the on-the-spot investigation and analysis of various factors that may induce the emergence of seedlings after emergence, it is possible to clarify the reasons. It is important to continuously summarize the lessons learned in production practice and try to avoid and overcome those artificial or natural adverse effects. In order to obtain the material basis of Miaoquan, Miaoyun, Miaozhuang, and high-yield production.
(Original title: Corn is not good, it turned out to be caused by them)

Stabilizer

It can slow down the reaction, maintain chemical balance, reduce surface tension, prevent light, thermal decomposition or oxidative decomposition. it mainly includes lead salts, metal soaps, organic tin, organic antimony, organic rare earths, pure organic compounds. Thermal stabilizers commonly used in industry mainly include lead salts, metal soaps, organic tin, organic antimony, organic rare earths, pure organic compounds, etc.

1.1 Organotin
(1) Excellent transparency The biggest advantage of organotin stabilizers is that they have excellent transparency. The use of organotin stabilizers in PVC formulations can produce crystalline products. Because of this, organic tin can be used in bottles, containers, corrugated boards, various types of rigid packaging containers, hoses, profiles, films, etc.
(2) Extraordinary thermal stability In terms of thermal stability, there is no other type of thermal stabilizer that can surpass it. Therefore, it is the preferred stabilizer for rigid PVC, and some varieties have better performance in soft products. Suitable for all PVC homopolymers, such as emulsion, suspension and bulk PVC, as well as vinyl chloride copolymers, graft polymers and polymer blends.
(3) The product is non-toxic. Most organotin stabilizers are non-toxic, and the migration of organotin stabilizers in rigid PVC is minimal. Therefore, organotin stabilizers are the preferred heat stabilizers for PVC for food contact.
(4) Good compatibility. Organotin stabilizers have good compatibility with PVC, so there is generally no precipitation on the metal surface, such as lead salt stabilizers and metal soap stabilizer systems.
(5) Poor lubricity Sulfur-containing tin stabilizers have poor self-lubricity. Therefore, many commercially available sulfur-containing organotins are equipped with lubricants to prevent hot melt from adhering to processing equipment during processing.
(6) High cost Compared with other types of stabilizers, the overall performance of organotin stabilizers is closer to the ideal stabilizer. However, all organotin stabilizers, regardless of their structure, have the main disadvantage that their manufacturing cost is much higher than that of lead stabilizers or metal soap compounds. In recent years, by adopting new synthetic technology, or reducing its usage in formulas, its formula cost has been reduced. In the 1970s, foreign countries developed low-priced tin products, which reduced the tin content, which also reduced the price to a certain extent.
1.2 Lead salt
(1) l Excellent stability experiments proved that among the commonly used basic lead salts, the heat resistance of sulfite is better than that of sulfate, and the heat resistance of sulfate is better than that of phosphite. The tribasic lead sulfate, which is widely used in the PVC industry, has a higher effective lead content and shows better thermal stability than other products.
(2) Excellent insulation. Because lead salt is non-ionic and non-conductive, it is inert, which makes lead salt stabilizers widely used in wire and cable industries.
(3) Excellent weather resistance. Many salt compounds can act as white pigments and can show strong covering power, so they have strong weather resistance.
(4) Poor transparency Transparency is a problem related to weather resistance. When used in wires, cables and record materials, there is no need to care about transparency, because most of these products are white or very dark black.
(5) Inexpensive lead salt stabilizer is the lowest price among all stabilizers. Therefore, despite the continuous introduction of new stabilizers, lead salt stabilizers still dominate the stabilizer market after half a century. The composite lead salt introduced to solve the dust and dispersion problem has increased in price, but still maintains a competitive advantage with other types of stabilizers.
(6) The toxicity of the toxic lead salt stabilizer limits its application in many occasions with strict hygiene requirements. For example, many countries have revised the lead content standards in drinking water, and it is no longer possible to use lead salt in PVC water pipes.
(7) Poor dispersibility The dispersibility of salt lead is poor, but the newly launched one-package product is equipped with lubricants, which solves the dispersibility problem to a certain extent. Because of the above characteristics of lead salt stabilizers, they are especially suitable for high-temperature processing. They are widely used in various opaque hard and soft products and cable materials, such as various pipes, plates, indoor and outdoor profiles, foam plastics, artificial leather, and wires. Cables, records, welding rods, etc. The most important lead salt stabilizers are tribasic lead sulfate, dibasic lead phosphite, and dibasic lead stearate.
1.3 Organic antimony
(1) Better stability. The organic antimony stabilizer has basically the same color stability and lower melt viscosity as organotin at the same temperature. In the twin-screw extrusion process, the effect is particularly outstanding when used in combination with calcium stearate. .
(2) The price of organic antimony stabilizer is much lower than that of methyl tin or butyl tin. In addition, the amount of organic antimony used is relatively low, so the use of organic antimony can achieve a better performance/price balance.
(3) The product is non-toxic. In the United States, when a twin-screw extruder is used to manufacture PVC pipes, the PVC water supply pipe manufactured with a formula composed of antimony stabilizers, calcium stearate and other lubricants conforms to the U.S. NSF (National Sanitation Foundation) )Regulation.
(4) Poor transparency and light stability. The transparency of organic antimony compounds is not as good as organotin stabilizers, and it is also lower than the barium/fu and calcium/zinc metal soap system. It is close to lead salts and has poor light stability, so antimony is stable. The agent is mostly used for indoor products without color requirements. The antimony stabilizer itself is also required to be stored in an opaque container.
(5) Poor lubricity. Antimony stabilizers have poor lubricity. Therefore, its use must be combined with a large amount of lubricant without exception.
1.4 Metal soap
(1) The tin soap stabilizer Fu soap is the best type of metal soap. Its advantages are also reflected in the absence of initial coloring, and can produce colorless and transparent products; excellent light stability; it has the effect of preventing precipitation and adhesion. . However, because tin salt is toxic, there are strict regulations on its manufacture and use in the Labor Safety and Health Law. In recent years, the use of Fuzao has shown a downward trend.
(2) Zinc soap stabilizerThe thermal stability of zinc-based stabilizer to PVC is extremely poor. The sample with zinc soap suddenly turns black when heated, that is, the so-called "Zine burning" phenomenon occurs, but it has the following advantages: The initial coloring is excellent; the effect of preventing fouling is good; it can improve the weather resistance; many zinc soaps are recognized as non-toxic stabilizers, so they can be used in non-toxic formulations with calcium soaps.
(3) Barium soap stabilizer Barium compounds have good thermal stability and good lubricity, but the red initial coloration occurs during processing, and it is easy to cause sticking to the roller.
(4) The stability of calcium soap stabilizer is poor, but it is recognized as a non-toxic additive in the world and has excellent lubricity.
(5) Other metal soap stabilizers used in the industry include magnesium stearate, file stearate, aluminum stearate, potassium stearate, etc., among which magnesium stearate is similar to calcium stearate and can be used Materials that are in contact with food; aluminum stearate is similar to zinc stearate, and is approved by the U.S. FDA and the Japanese Vinyl Chloride Food Hygiene Association for food packaging; Stearic Acid files and potassium stearate are also non-toxic products and belong to lead salts , Tin soap and barium soap substitute.
(6) The performance requirements of the composite metal soap stabilizer processing industry for stabilizers are various, and a single metal soap often cannot meet the use requirements, so the use of composite stabilizers has become a trend. A single metal soap compound is rarely used in the PVC industry, and it is usually a compound of several metal soaps. This compound is not a simple addition of properties, but takes advantage of the synergy between the components. The composite metal soap stabilizer generally includes the stabilizer main body (i.e. metal soap), solvent (organic solvent, plasticizer, liquid non-metal stabilizer, etc.), functional additives (auxiliary stabilizer, transparency modifier, light stabilizer, Lubricants, etc.). According to the form, it is divided into solid compound and liquid compound. According to the main component, it can be divided into calcium/zinc compound stabilizer, barium/fu compound stabilizer, barium/zinc compound stabilizer, etc. Among them, the calcium/zinc composite stabilizer has a pivotal role in replacing toxic metals because it is non-toxic.
1.5 Rare earth stabilizer
(1) Excellent thermal stability The thermal stability of rare earth stabilizers is better than traditional lead salt series and barium/zinc, barium/ho/zinc stabilizers. In some applications, rare earth stabilizers can partially or completely replace organotin.
(2) Good transparency. The refractive index of rare earth stabilizers is very close to that of PVC Resin, which can replace traditional organotin and be used in the field of products with higher transparency requirements.
(3) Excellent weather resistance. Rare earth elements can absorb 230-320nm ultraviolet light. Therefore, rare earth stabilizers have anti-photoaging effects and are suitable for outdoor products such as PVC corrugated boards and window materials.
(4) Excellent electrical insulation properties. Some rare earth multifunctional stabilizers can be used to replace lead salt stabilizers in cable material formulations, and their electrical insulation properties are comparable to lead salts.
(5) Non-toxic, safe and hygienic. Rare earth elements are low-toxic elements and have no toxic hazards to the human body in their production, processing, transportation and storage. Rare earth stabilizers are non-toxic products and can be used in food packaging and medical packaging products.
(6) The processing performance is slightly worse. In the case of a large amount of rare earth stabilizer, the roll release of the material is not ideal, and there is a tendency to press out. Generally, better results can be achieved by using stearic acid or calcium stearate in combination.
In summary, rare earth stabilizers can be used for water pipes, injection pipe fittings, window frame profiles, door panels, wire ducts, foam products, artificial leather, cable materials, soft and hard transparent products, food packaging materials, etc.
1.6 Auxiliary stabilizers Auxiliary stabilizers include phosphite, epoxy soybean oil, hindered phenols, etc., which mainly rely on the synergistic effect between metal stabilizers to improve the stabilizing effect, and are generally called co-stabilizers. In addition to compounds such as mesaminocrotonic acid ester, 2-phenyl saccharin, vein derivatives, and diketone can be used in combination with metal stabilizers to improve the effect of metal stabilizers, they also have a certain stabilizing effect. Such compounds are usually called pure organic stabilizers. With the development of PVC stabilizers today, the progress of metal stabilizers is relatively slow, and the research and development of auxiliary stabilizers are unprecedentedly active, which has constituted a major trend in the field of PvC stabilizers. Auxiliary stabilizers are rarely used alone, and are often used in conjunction with primary stabilizers to improve initial coloration or improve long-term stability.

Lead Salt Stabilizer, Compound Stabilizer,Pvc Stabilizer,Titanium Dioxide Anatase

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