How many days does wheat mature?

According to the different temperature requirements, wheat can be divided into two physiological types: winter wheat and spring wheat, and different types are planted in different regions. Spring wheat is planted in Heilongjiang, Inner Mongolia and Northwest China, sown in March-April, matured in July-August, and has a short growth period of about 100 day. Winter wheat is planted in Liaodong, North China, South Xinjiang, Shaanxi and Yangtze River provinces. Sow in August ~ 65438+February in autumn, mature in May ~ July the following year, and the growth period is about 300 days.

About 654.38 million years ago, the invention of agriculture laid the foundation for the emergence of civilization in the Near East. But for a long time, archaeologists have different opinions on how agriculture came into being. Some people think that it appeared in a separate place near the Mediterranean and then spread out from there; Others believe that it has multiple independent origins. The latter view is supported by new evidence due to the archaeological discovery of early agricultural sites in Iran.

wheat

Wheat (5 sheets)

No matter when agriculture appeared 1 time or 100 times, scientists believe that it first appeared in the fertile Moon Bay (extending from the Mediterranean to the vast area of Iran). In the past few decades, most of the research has focused on the rich western part of Wan Yue-including Israeli, Palestinian, Syrian, Jordanian and Turkish.

Excavation in those areas shows that as early as 654.38+300 million years ago, local hunters began to collect and plant seeds of wild cereals and beans such as wheat, barley and lentils. Thousands of years after the emergence of this farming culture, these wild plants have mutated into new artificially planted species, which are easier to manage and harvest, and also make farming more productive and efficient.

The geographical distance from zagros mountains to the rich western Moon Bay also implies the independent origin of crop cultivation civilization. The 9,800-year-old cultivated wheat found in Chogha Golan area may also have been introduced from further west.

The origin of wheat is in the crescent land of West Asia. The earliest discovery of wheat sites in China is near Hemudu Valley. Peacock River Basin in Xinjiang, also known as Loulan; Carbonized wheat 4,000 years ago was also found in Loulan Xiaohe Cemetery. Four thousand years ago, the desert oases in the lower reaches of Tarim River and Peacock River were rich in water resources and 40% vegetation coverage. At that time, there were fish in the water, birds in the forest, green grass for grazing and land suitable for farming. In a small environment, there is quite a good living soil. But the only problem is also the most critical one, which is the fragility of desert oasis ecology. A little change will bring unexpected disaster to life.

Wheat was rarely planted in the south, and it was gradually popularized to the south after the Han Dynasty. Jin Shu Wu Xing said: "In the second year of Daxing in Yuan Di (AD 3 19), people starved to death in Wu Jun (now Jiangsu), Xing Wu (now Huzhou, Zhejiang) and Dongyang (now Dongyang, Zhejiang)." It can be seen that at the beginning of the fourth century, wheat has achieved a certain position in Jiangsu and Zhejiang provinces. Since then, it has been promoted one after another, mainly by farmers themselves, and sometimes by dynasty governments or local officials. In the early years of the Southern Song Dynasty, northerners moved to the middle and lower reaches of the Yangtze River and Fujian, Guangdong and other provinces. Northerners used to eat wheat, and the demand for wheat suddenly increased, so the price of wheat rose sharply, which stimulated the production of wheat. Therefore, the cultivation of wheat has expanded rapidly. Zhuang in the Southern Song Dynasty said in his Braised Chicken Ribs (/kloc-at the beginning of the 2nd century): "At this time, wheat fields are contiguous, no less than the Huaihe River." That is to say, it is no less than the north.

Wheat and rice have different growing seasons. As long as it is arranged, wheat can be planted after harvesting rice in autumn, transplanted after harvesting wheat in summer, and the same land can be harvested twice a year. The popularization of wheat does not hinder the planting area of rice. In the Northern Song Dynasty, Zhu's "Continuing Wu Jun Tu Jing" (1084) said: "Wuzhong has fertile land and rich products. After harvesting wheat, rice is planted twice a year, and rice has its morning and evening. " Later, in the Southern Song Dynasty, Chen Fang's agricultural books (1 149) and Wang Zhen's agricultural books (13 13) also talked about the double cropping system of rice and wheat. Moreover, according to Wang Zhen's "Agricultural Book", the technical level of planting wheat in the southern region is equivalent, and the yield per unit area is relatively high, which is not worse than that in the north. [6]

Wheat not only spread to the south, but also developed in the north. There was an agricultural proverb before the Yuan Dynasty: "Harvesting wheat is like putting out a fire". In terms of production tools, wheat bran (shàn fan, a long sickle) was used in the Tang Dynasty, and improved in the early Yuan Dynasty, creating a wheat harvester made of wheat cages, wheat bran and wheat straw (a bamboo stick shaped like a dustpan, slightly larger, with a blade on one side). When the swinging blade is used to cut wheat ears, the usage method is as follows: the wheat cage is installed on a wooden frame with four small wheels under it and dragged around the waist with a rope. The reaper cuts the ears of wheat with a trowel, and the ears of wheat fall into the chuo, and then the wheat in the chuo is returned to the cage. When the cage was full, it was pulled to the threshing floor. According to Wang Zhen's "Agricultural Book", "Ten acres can be harvested in one day, which is ten times faster than cutting with a sickle in the south." If we hadn't planted a lot of wheat, we wouldn't have created this fast wheat harvester. [6]

According to the estimation in Tiangong in the Ming and Song Dynasties, wheat accounted for a little more than 15% of the total grain output in China at that time. Although this is a rough estimate, it can be clearly seen that wheat ranks second only to rice among the food crops in the Ming Dynasty. [6]

People often say that "wheat" is wheat.

Photographic atlas of wheat

Wheat photo album (20 photos)

Of course, there are other kinds of wheat, such as barley and oats. In ancient Europe, people mainly ate barley, and it was not until16th century that it was replaced by wheat. Barley mainly makes beer in the world, and it is a world-class drink. 80% of the world's barley production has turned into beer and poured into people's stomachs. 1 kg barley can probably make 4 ~ 5 kg beer. The unique bitterness of beer is also caused by adding hops.

China has implemented quota management for wheat imports since 1996. Since April 2002, the export tax rate of corn, wheat and rice has been zero, which has improved the export competitiveness of China's grain varieties. The increase of wheat import and export is related to varieties. It exports aged wheat (mainly spring wheat) for feed to neighboring countries such as South Korea at a lower price, and imports high-quality durum wheat from countries such as the United States. According to the agreement reached between China and the United States, after China's accession to the WTO, it will reduce the tariff on agricultural products to 14.5%- 15% within five years, open the import of agricultural products such as wheat and implement the "tariff ratio quota system". By 2006, the wheat quota should be increased from 2 million tons to 9.3 million tons, and the private sector should initially be 10%. China government insists on retaining tariff quotas in world trade negotiations.

Wheat is one of the most important rations in China, and the development of wheat industry is directly related to national food security and social stability. The domestic resource environment, grain supply and demand pattern and international trade situation have all undergone profound changes.

China has a large population, and ensuring national food security has always been the top priority in governing the country. In 20 13, the central economic work conference and the central rural work conference put food security in the first place, and clearly put forward that the strategic policy of national food security is "taking ourselves as the mainstay, basing ourselves on the domestic market, ensuring production capacity, moderately importing, and supporting by science and technology", and the strategic goal is to ensure that food is basically self-sufficient and rations are absolutely safe.

Under the new situation of "four modernizations" synchronization and opening to the outside world, in order to refine and implement the new food security strategic principles and objectives put forward by the central government, the author has made a systematic and in-depth thinking on the development of domestic wheat industry, and holds that six outstanding problems facing the development of wheat industry need to be paid attention to and dealt with.

Planting technique

Tillage and soil preparation

Tillage and soil preparation can make the topsoil soft, the soil broken flat, the dry and wet conditions suitable, promote the whole emergence of wheat and ensure the coordinated growth of underground and aboveground parts, which is an important link to create high-yield soil conditions. The specific methods vary according to paddy field, dry land and previous crops.

1. Soil preparation for multiple cropping of rice and wheat in wheat fields Due to long-term immersion in paddy fields, the soil is hardened and the permeability is poor, so it is necessary to promote soil maturation through paddy-upland rotation and dry-wet alternation. The characteristics of soil preparation are that when the previous crops are harvested earlier, they should be plowed as soon as possible, and shallow ploughing and fine harrowing should be carried out before the kang soil is fully dried and sown, so that the upper part is soft and the lower part is solid. As a seed-making field of late rice or hybrid rice, due to the short interval between harvesting and sowing, it is necessary to ditch and drain rice seeds when sowing, so as to try to dry the thin slices in the sun for a short time. On the premise of not delaying the timely sowing of wheat, shallow soil preparation can also be done to create a good seedbed and growth foundation for wheat.

2. The soil preparation of dryland wheat should be based on increasing the deep ploughing layer year by year, combined with increasing the application of organic fertilizer and improving water-retaining fertilizer, according to different multiple cropping forms. That is to say, if the previous crops are harvested earlier, such as spring corn, sorghum, tobacco and so on. Clean up the stubble first, then dig the kang soil deeply, let the stubble rot and accept the autumn rain. Use a shallow rake to reduce evaporation after rain. Another kind, such as sweet potato and cotton, has a short harvest period. If conventional methods are used, the sowing date will be delayed, which is one of the important reasons for the low yield of wheat in southwest China. Therefore, on the one hand, it is suggested to loosen the soil between rows in the late stage of the previous crop, and then plow and level it when planting wheat; On the other hand, continuous operations such as digging potatoes, leveling, fertilizing and sowing are advocated to ensure timely sowing of wheat.

Less tillage, no tillage and semi-dry farming

1. Less tillage and no tillage The so-called less tillage and no tillage means that compared with traditional land preparation, the number and intensity of land preparation are reduced. For wet soil,

wheat

wheat

Wheat fields with high viscosity, difficult to cultivate and easy to destroy soil structure avoid unnecessary or even harmful cultivation, so this is the development and improvement of wheat land preparation technology. According to the study of no-tillage of wheat after rice, the mechanism of increasing yield can be summarized as follows.

(1) Good soil structure and no-tillage with water did not disturb the soil layer, which kept the original pores of paddy soil and avoided adhesion caused by wet tillage. Compared with ploughing, the soil bulk density of no-tillage topsoil is 1. 15 ~ 1.20 and 1.34 ~ 1.40, respectively, and the water and gas are harmonious.

(2) It is beneficial to improve the sowing quality. On the premise of timely sowing, because the flat field is conducive to digging holes or sowing in ditches, planting norms should be implemented to avoid deep planting, overgrowth and seed exposure caused by rough cultivation and rotten seeds, so as to achieve neat, even and Miao Zhuang seedlings.

(3) Developed root system, strong lodging resistance and good soil structure are beneficial to root system development and water absorption. According to multi-point investigation, no-tillage has more secondary roots per plant than ploughing 16.0%. 32p tracer was used to determine the filling period. On the 8th day after labeling, the number of pulses increased by 63.0438 0%.

(4) Strong seedlings grow early, and the yield is significantly improved. No-tillage land has a good soil ecological environment. Quick emergence, early tillering and obvious growth advantages. The leaf area index of no-tillage in each growth period is high, the photosynthetic capacity of the population is strong, and the yield per unit area is increased by 5 ~ 20%.

Wheat and corn seeder

Wheat and corn seeder

After four years' research, there is no adverse effect on the following rice, but the relationship between long-term no-tillage and soil fertility, pests and diseases needs to be explored. In addition, there are many weeds in no-tillage fields, and it is easy to remove fertilizer in the later stage, so appropriate supporting measures should be taken.

2. Semi-arid cultivation of wheat is an important link of natural no-tillage in paddy field. After the semi-arid rice is harvested, the original ridge can be slightly modified to sow wheat. Width of wet mud field 170 ~ 200 cm, generally 27 ~ 40 cm, trench width 33 ~ 40 cm, trench depth 27 ~ 33~40cm. After covering the rice stubble and fertilizer with soil in the ditch, sow after airing for 65438 0 ~ 2 days, and cover the seeds with dry residue fertilizer or fine soil. During the growth period of wheat, a certain water level should be maintained in the ditch (from12 to15 cm in the early stage and 18cm in the later stage) to keep the ridge surface dry, which is not only beneficial to the growth of wheat, but also ensures the timely sowing of rice, which is an effective way to improve the utilization rate of winter paddy fields.

The yield level of semi-arid wheat under dry farming conditions can generally reach 70 ~ 80%, and some soil types are higher than dry farming level, so it has been widely planted in three southwestern provinces. The reason for its yield increase is partly the same as that of less tillage and no tillage, and its outstanding function lies in changing the hydrothermal conditions of soil. On the one hand, the ridge and furrow extend the depth of wheat root system about 10 cm, and the ridge surface has good permeability, and the capillary rises to coordinate moisture; On the other hand, furrows and ridges increase the surface area of soil, which is 1.2 ~ 2.0℃ higher than that of flat cultivation during the day, up to 4℃, and 0.3 ~ 0.7℃ lower than that of flat cultivation at night, and the light receiving area of soil increases by about 200 ~ 400㎡/ mu. Under good water, heat and gas conditions, it can promote microbial activity and decomposition of organic matter, and improve soil fertility.

Because of the strong fertilizer supply ability of semi-arid cultivation, nitrogen should be properly controlled in the early stage to avoid increasing ineffective tillers, but it is easy to remove fertilizer in the later stage, and nitrogen and phosphorus should be supplemented on the basis of increasing organic fertilizer. In addition, semi-arid farming needs more labor such as ridging, sowing and fertilization, and it needs to improve the degree of mechanization and other supporting technologies to improve the wheat production level in such low-and medium-yield fields.

High yield technology

First, pay attention to the choice of high-fat water plot. High-yield and high-quality wheat varieties need comprehensive and sufficient soil nutrients to meet the needs of high-yield cultivation. Therefore, it is advisable to choose plots with high soil fertility and good irrigation conditions, increase the application of organic fertilizer and adopt formula fertilization technology.

Second, pay attention to the appropriate late sowing and determine the appropriate basic seedlings according to the characteristics of varieties. It is necessary to prevent the broadcast volume from being too large, resulting in passive management in the later stage.

Third, pay attention to prevent lodging and re-apply jointing fertilizer. Some popularized high-quality wheat varieties are not resistant to lodging, especially in wheat fields with large population. Chemical control treatment must be carried out once before turning green and jointing, and paclobutrazol or Maiyefeng can be sprayed. It is necessary to supplement jointing fertilizer, control the formation of redundant inverted panicles, and promote large panicles and more grains.

Fourth, pay attention to watering slurry, wheat yellow water and spraying foliar fertilizer to prevent premature aging. Irrigation and grouting wells play an important role in increasing grain weight and preventing dry and hot wind. When the weather is dry, the application of wheat yellow water is beneficial to interplanting the next crop and preventing premature aging. Spraying 0.2% ~ 0.3% potassium dihydrogen phosphate and other foliar fertilizers for 2 ~ 3 times in the first half of May, combined with pest control, can reduce the harm of dry hot wind and obviously increase production.

Fifth, pay attention to the prevention and control of pests and diseases. Generally speaking, high-quality wheat is more prone to diseases and pests, such as wheat sheath blight and powdery mildew, and aphids occur earlier and heavier than conventional varieties. Should be based on the forecast, early prevention and control.

6. Spraying Maibao once just before heading and flowering of wheat is about 60-70% (as shown below), which can activate the biological enzyme activity in wheat, promote the development coordination of male and female organs, enhance the photosynthesis of functional leaves, obviously reduce the empty grain rate, improve the seed setting rate and 1000-grain weight, and thus achieve the effect of increasing production.

Drought resistance and yield increase

Deep and shallow rotation tillage, with soil to store water. Deep tillage can break the bottom of plough, increase water permeability, increase water storage capacity, promote root binding, expand root absorption range and improve water and fertilizer utilization rate. However, deep cultivation must be adapted to local conditions and time. Generally, deep ploughing is carried out in the years with early land preparation, abundant precipitation and sufficient water, with the ploughing depth of 22-25 cm, and then harrowing. After ploughing, there is little rain and drought, which often leads to serious water loss due to false soil. Practice has proved that in 3-4 years, dryland wheat can not only achieve the purpose of deep tillage and soil improvement, but also increase the chances of soil subsidence and soil conservation, which is an important measure to increase the yield of dryland wheat.

Increase fertilizer and adjust water with fertilizer. Organic fertilizer should be applied as far as possible in dryland wheat fields, and inorganic fertilizer should be applied in sufficient formula, especially phosphate fertilizer, in order to improve soil, improve soil fertility, and improve water storage and fertilizer conservation capacity and water use efficiency. For general plots, 2500-3000 kg of organic fertilizer, 50 kg of ammonium bicarbonate and 50 kg of calcium superphosphate can be applied per mu, and appropriate amount of potassium fertilizer and trace fertilizer can be applied as appropriate; If the soil fertility is poor, 40-60 kg of standard nitrogen fertilizer and 50- 100 kg of phosphorus fertilizer can be applied continuously for three or four years. In dry land and high-yield wheat fields, the fertilization method of "one-time bombardment" can be adopted, that is, all fertilizers are combined with soil preparation and applied to the soil at one time as base fertilizer, in which nitrogen fertilizer should be applied deeply and phosphorus fertilizer should be applied lightly to facilitate the cultivation of strong seedlings before winter. [7]

Reduce water evaporation by pressing. Suppression in single ridge stage of wheat can increase the number of secondary roots per plant, improve the water absorption capacity of plants, destroy the surface capillaries and reduce water evaporation.

Common diseases and prevention methods

The diseases that harm wheat include stripe rust, leaf rust, stem rust, smut, loose smut, yellow dwarf, red dwarf, take-all disease, scab and leaf spot. Pests include wheat aphid, wheat fly, midge, red spider, leafhopper, grub, golden needle worm, mole cricket, wheat sawfly, wheat straw fly and so on.

(1) Clear ditches and dig large canals in time, improve a set of ditches in the field, drain open water, reduce dark waterlogging, and do everything possible to reduce water accumulation in the plough layer, which is the main goal to prevent wheat from wet damage. Dredge the silt in deep ditches and ditches that have been in disrepair for a long time, raise the fields and lower the groundwater level, and prevent frequent rainfall or heavy rain in winter and spring, which is beneficial to drain the stains and ensure that the field water enters the ditches unimpeded. At the same time, do a good job of "three ditches". Dry land wheat or paddy field wheat must open one ditch, one ditch and one waist ditch to achieve communication, communication, rain and drought, so as to avoid light and darkness. Advocate large-scale planting of irrigated wheat.

(2) Topdressing the seriously wet wheat fields, skillfully applying relay fertilizer as early as possible, and then applying fertilizer at jointing and booting stage to promote seedlings. Apply more hot organic fertilizers in winter, such as residual grass fertilizer, pig manure, cow dung, plant ash, ditch horse, human manure and human urine. Applying more phosphorus and potassium fertilizer is beneficial to root development, with strong stems and little damage.

(3) The harrow and hoe loosen the soil to loosen the moisture and raise the temperature. Enhance soil permeability, promote root system development, increase tillering and cultivate strong seedlings. Cutting grass can promote the growth of wheat seedlings, accelerate the transformation of seedling conditions, and increase the yield of wheat by increasing ears and grains.

(4) leaf protection and disease prevention. After rust, scab and powdery mildew occur, chemicals can be sprayed in time. In addition, "802" growth promoter, plant stress resistance and yield-increasing agent, Jiamu Harvest Liquid Fertilizer, Huimanfeng, Fufengbao and Wan Jiabao can also be sprayed. You can also spray "Plant Power 2003" 1 0ml clean water 10L,1time every 7 ~/0 days, and spray it twice continuously. It is suggested to apply Dodo rare earth pure nutrient and spray 20 ~ 30l clean water every 50g, with good effect.

Control rust

Agricultural control: a. Planting disease-resistant varieties according to local conditions and paying attention to the reasonable collocation and rotation of varieties are the basic measures to control wheat rust. The epidemic races of wheat rust change rapidly, and the epidemic races in different regions are different at the same time, so it is necessary to continuously cultivate varieties resistant to new epidemic races. B. adjust the sowing date. Such as Longnan, Longdong, North Sichuan, Guanzhong, North China and other vast winter wheat areas, it is not appropriate to sow early. The earlier sowing, the earlier and heavier the occurrence of autumn seedling stripe rust, which provided the local wintering bacteria source. Therefore, under the premise of preserving soil moisture, try not to sow early. C. timely ploughing, stubble clearing and intertillage, so as to eliminate autogenous wheat seedlings and reduce bacterial sources. D do a good job in the rational distribution of large-scale disease-resistant varieties and cut off the transmission route of bacteria sources. There is much rain and high humidity in wheat fields in southern China, which is beneficial to the development of rust. Strengthening ditch drainage can reduce injuries. E. reasonable and even fertilization. Control the amount of nitrogen fertilizer and appropriately increase the amount of phosphorus and potassium fertilizer to prevent the rust damage from being aggravated by greed for green and late maturity. Especially in areas where the soil lacks phosphorus and potassium fertilizers, increasing the application of these two fertilizers can reduce the harm of rust. F. Strengthen forecasting and control diseases by spraying drugs in time. [8]

Chemical control: A. Seed dressing with chemical agents to reduce pathogenic bacteria. In the plots with serious autumn seedling diseases all the year round, every 50 kilograms of seeds should be sown with 60- 15% triadimefon wettable powder or100g fast-gathering wettable powder. Must be dry mixed, fully mixed evenly, and strictly control the dosage. A little concentration will affect seedling emergence. B. Field control. In autumn and early spring, if rust centers are found in the field, drugs should be sprayed in time to control them. If the rate of diseased leaves reaches 5% and the severity is below 10%, triadimefon WP 50g or triadimefon EC 40ml, triadimefon WP 30g or 12.5% fast poly WP should be used per mu. In epidemic years, if the diseased leaf rate is more than 25% and the severity is more than 10%, it is necessary to increase the dosage, and spray it with the concentration of 2 ~ 3 times of the above dosage according to the severity of the disease. Commonly used drugs are: Fenxiuning, Subaoli, Guangkuling and 3% Guangkuling aqueous solution. [8]

Precautions: In the early stage of rust, the control effect is the best. In the event of an epidemic, chemical control should be carried out in the wheat fields with serious illness in time, so as to control the further spread of the disease and reduce losses. [8]

control of insect

Agricultural control: a. Planting disease-resistant varieties, especially slow (tolerant) powdery mildew varieties. In areas where serious diseases often occur, the resistance to varieties is higher, but it can be lower in general areas; B, reasonable close planting according to the variety characteristics and the fertility level of the wheat field; C. adopting correct cultivation measures can reduce the incidence rate. For example, fertilization should be reasonable, attention should be paid to the coordination of nitrogen, phosphorus and potassium fertilizers, and the application amount of phosphorus and potassium fertilizers should be appropriately increased. Pay attention to ditching and drainage in the southern wheat area, and water it in time in the northern wheat area to make the plants grow healthily and enhance the disease resistance. In addition, in areas where spontaneous wheat seedlings can survive in summer, the spontaneous wheat seedlings in fields and yards should be removed as much as possible before sowing in autumn to reduce the bacterial source in autumn seedling stage. [8]

Chemical control: Chemical control is the most important control measure when the planted varieties are not resistant to diseases or have weak resistance to diseases. The focus of chemical control is on areas with good growth, high yield and serious diseases and wheat fields. Commonly used drugs: A. Triadimefon, 8 grams of active ingredient per mu, sprayed 1 time from booting stage to heading stage of wheat, which can generally control the harm of this disease and also treat wheat rust. In areas with many diseases in autumn seedling stage, seed dressing with triadimefon can effectively control diseases in autumn seedling stage, reduce overwintering bacteria and treat various smut and rust in autumn seedling stage. The dosage of seed dressing agent is 0.03% of the seed weight (effective component); B baofengning, plant protection ning and compound fenxiuning have good control effect, and the dosage and usage are the same as triadimefon; C triadimenol (oxyxiuning), the application method is the same as that of triadimefon, and the dosage is halved; D. Sulfur preparations, such as lime-sulfur mixture with Baume degree of 0.5 ~ 0.8, colloidal sulfur solution of 200 times and 50% sulfur suspending agent of 0.5 kg per mu, generally need to be sprayed more than twice, with an interval of about 7 days each time, and the spraying time should be earlier. [8]

Precautions: The prophase control effect of powdery mildew is the best. If most of the leaves, stems and ears of the whole plant are diseased, spraying drugs is basically ineffective, and the disease is mainly controlled by the disease resistance of the variety itself, but the spread of the disease needs to be controlled. [8]

Control head smut, take-all disease and powdery mildew

Usually, seed dressing with chemical agents can not only prevent wheat smut, but also effectively control the occurrence and harm of wheat rust, take-all disease and powdery mildew, and reduce the amount of overwintering bacteria.

(1) In areas where head smut, head smut, root rot, sheath blight and take-all disease occur, 40% pentachloronitrobenzene can be dry mixed, and the dosage is 0.5% of the weight of wheat seeds (i.e. 40g per mu, about 8kg of mixed wheat) to control head smut of wheat; You can also choose a bag of 6% Tebuconazole (Likexiu) suspending agent (10 ml), add 0.8- 1 kg of water, seed dressing 50-70 kg, or 2.5% Teflon (Xerox) suspending agent to seed dressing wheat according to the recommended dosage, and also treat autumn seedling rust and powdery mildew. Seed dressing with 15% triadimefon wettable powder or adding 5 kg of water to 20% triadimefon EC 1 kg and 500 kg of wheat seeds can prevent powdery mildew and leaf rust.

(2) In the areas with serious take-all disease of wheat, 12.5% silibendazole (take-all net) suspension can be used for seed treatment, which has good control effect on take-all disease of wheat. Generally, a bag (20 ml) is completely eroded. First, add 300-500 ml of water to mix 20-25 kg of seeds. After mixing, sow for 6- 12 hours (which is conducive to the development of drugs and killing germs carried by seeds), and then dry the seeds in the shade.

(3) In areas where wheat yellow dwarf disease and dwarf disease occur, seeds can be treated with imidacloprid to control poisonous insects, control the occurrence and harm of wheat yellow dwarf disease and dwarf disease, and treat underground pests at the same time.

(4) In areas where a variety of pests and diseases are mixed, it is necessary to vigorously promote the application of seed coating agents or seed dressing agents compounded with fungicides and pesticides for coating or seed treatment. All localities should choose the appropriate formula of seed coating agent or seed dressing agent according to the main local pests and diseases, and its dosage is generally the same as that of single compound (mixed) agent. [9]

Species classification editor

Generally, the following classification methods are adopted.

(1) According to the skin color of wheat seeds.

Wheat can be divided into red-skinned wheat and white-skinned wheat, which are called red-skinned wheat and white-skinned wheat for short. The epidermis of red-skinned wheat (also known as red-grained wheat) is dark red or reddish brown; The epidermis of white-skinned wheat (also known as white-grained wheat) is yellow-white or milky white. Red and white wheat mixed together is called mixed wheat.

(2) According to the quality of wheat grain.

According to the difference of grain quality, wheat can be divided into hard wheat and soft wheat. The endosperm structure of durum wheat is dense and translucent, also called horny or glassy; Soft wheat endosperm structure is loose and gypsum-like, also known as silty. As far as wheat grain is concerned, when its keratin accounts for more than 1/2 of its cross section, it is called keratin grain and durum; When its cutin is less than 1/2, it is called silty soft wheat. For a batch of wheat, according to the China standard, durum wheat refers to wheat with cutin rate not less than 70%; Soft wheat refers to wheat with flour content of not less than 70%.

(3) Classification according to sowing season

Wheat can be divided into spring wheat and winter wheat according to different sowing seasons. Spring wheat refers to the wheat sown in spring and harvested in summer or autumn of that year; Winter wheat refers to wheat sown in autumn and winter and harvested in the summer of the following year.