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2023-01-29

Section I Propagation of virus-free seedlings1. Strawberry virus-free seedlingsStrawberry virus-free seedlings are those that have completely removed strawberry virus. Strawberry virus disease is a disease caused by strawberry infection, which shows two symptom types in cultivation: yellowing type and shrinking leaf type. Strawberry virus disease has a wide range of hazards. According to incomplete statistics, there are as many as 62 kinds of strawberry disease viruses, among which Strawberry mottle virus (SmoV), Strawberry mild yellow edge virus (SMTEV), Strawberry vein-band virus (SVBV) and Strawberry crinkle virus (sCrV) are four main viruses infecting strawberries in China, with a total infection rate of 80.2%, The infection rate of single virus is 41.6%, and the combined infection rate of two or more viruses is 38.6% (Ma Chongjian, 2004). Strawberries infected with virus disease grow slowly, their leaves shrink, their fruits become smaller, deformed, and their quality decreases year by year. At present, there is no medicine to control the virus disease. The use of virus-free cultivation seedlings such as strawberry stem tip is an effective way to control the virus disease, improve the quality of strawberry and improve the yield of strawberry. Strawberry virus-free seedlings have the characteristics of fast growth, vigorous growth, thick stems and leaves, strong resistance to disease, high temperature and cold, many flowers, high fruit setting rate, large fruit, neat and uniform, bright color, no abnormal fruit, high yield and good economic benefits, and are generally welcomed by fruit farmers. However, virus-free strawberry seedlings will be re-infected with the virus under field production conditions, and the infection rate is generally 10%~20% per year. Therefore, the majority of fruit farmers can continue to ensure high economic benefits by replacing the virus-free seedlings after 2 to 3 years of application.Qin Lanying et al. (1988) showed that stem tip culture had different degrees of virus removal. The smaller the stem tip, the greater the chance of virus removal. The higher the virus removal rate of the stem tip below 0.3 mm, and the tissue culture seedlings did not carry virus; Only 20% of the stems above 0.5mm were virus-free. After heat treatment, the effect of virus-free was significantly increased by taking stem meristem for culture, which was proved to be more reliable by electron microscope observation.The stem tip tissue culture of strawberry virus-free seedlings goes through the steps of explant selection, induction culture, proliferation culture, rooting culture, etc. Generally, from June to August, select middle-aged, disease-free, pure and healthy plants with fine weather, and cut 2~3cm stolon segments with growth points from the new shoots as explants, and wash them with running water. Place the surface cleaned explants on the ultra-clean workbench, disinfect the surface with 70% ethanol for 1 minute, discard the ethanol, add 0.1% mercuric chloride and 1 drop of Tween-20 to disinfect for 8 to 10 minutes, and shake it constantly, then wash it with sterile water for 5 to 8 times, use sterile filter paper to absorb the water, remove the scales, and use the scalpel to pick up 0.2 to 0.3 mm of the stem tip under the dissecting microscope, and inoculate it in the stem tip induction medium. Stem tip culture conditions: daytime temperature 25 ℃ soil 2 ℃, light intensity 30~60 umol/(m2. s); The temperature at night is 18 ℃, the soil temperature is 2 ℃, the culture is dark, and the daily illumination is 12-16 hours. After induction and culture for 2 to 3 months, when the cluster adventitious buds are 1.5 to 2.0 cm, the test-tube plantlets that have passed the virus test are inoculated on the proliferation medium for multiplication. The multiplication culture is subcultured every 20 to 30 days (the total number of subcultures is not more than 8), and the seedlings with a height of 2 to 3 cm are selected to be transferred to the rooting medium for rooting culture. After 20~30 days of induced rooting culture, tissue culture seedlings of complete plants can be formed.2. Application of growth regulators in strawberry virus-free seedling propagationIn the process of stem tip tissue induction culture and proliferation culture, growth regulators have significant effects on improving shoot tip germination rate, subculture proliferation and promoting rooting.(1) Paclobutrazol: In strawberry tissue culture, with the increase of differentiation times and subculture times, the test-tube seedlings degenerated. Such as petiole thinning, leaf yellowing, and reduced differentiation rate. In addition, the survival rate of transplanting is one of the key factors for the success of rapid propagation of strawberry virus-free seedlings, and the survival rate of transplanting of test-tube seedlings is directly related to the rooting of test-tube seedlings. In the rooting stage, the plantlets with thin and weak yellowing have poor rooting effect, and the survival rate is low after the bottle is out. At present, the application of paclobutrazol in strawberry tissue culture has solved this problem well.Zhang Xitai et al. (1997) used strawberry tube seedlings that have been subcultured for five times and have grown thin, thin and yellow as the test material, added 0.2~1.0mg/L15% paclobutrazol and 0.25mg/L6-BA to MS medium for subculture, and added 0.2~0.8mg/L15% paclobutrazol and 0.2mg/L6-BA for rooting culture. The results showed that paclobutrazol had obvious dwarfing effect on strawberry tube seedlings in subculture. With the increase of the concentration of paclobutrazol, the rhizome of the plantlets regenerated from the test-tube plantlets gradually became thick, the petiole was short and thick, the leaves were thick, and the chlorophyll content was high. Compared with the control, the rhizome thickness increased by 31.6%~174.4%, the petiole length shortened by 7.3%~71.0%, and the differentiation multiple increased by 14.3%~221.4%. When the concentration of paclobutrazol was increased to 0.6mg/L, the differentiation times of plantlets in vitro began to decline. In strawberry rooting culture, paclobutrazol and 6-BA significantly promoted the root system growth of test-tube seedlings. Compared with the control, the number of roots increased by 24.3%~543.0%, and the effect of adding 0.4mg/L15% paclobutrazol and 0.2mg/L6-BA to 1/2MS medium was better.According to Ruan Long et al. (2002), adding 0.2~0.6mg/L paclobutrazol to 1/2MS Fengxiang strawberry virus-free seedling rooting medium can promote the increase of rooting number, root thickening and growth of strawberry virus-free seedlings. Compared with the rooting medium without paclobutrazol, the rooting number of Fengxiang test-tube seedlings increased by 10.9~15.7, the root diameter increased by 0.24~0.39 mm, and the root length increased by 0.27~0.70 cm, among which the treatment effect of adding 0.4mg/L paclobutrazol was better.Section II Regulate the growth of stolon and promote the elongation of the top inflorescence1. Strawberry stolon and top inflorescence growthStrawberry stolon is a vegetative reproductive organ on the ground of strawberry, which is sprouted from the axillary buds of new stems. Generally, in the late fruit setting and after harvest, the sunlight in early summer is enhanced, the temperature is increased, and the stolons sprout from the dormant axillary buds formed last autumn. A bract and axillary bud are formed on the first node of the stolon, and the axillary bud remains dormant. The growth point on the second node differentiates the leaf primordium. When 2 to 3 leaves are exposed, adventitious roots are produced, which are embedded in the soil, forming a first-level stolon seedling. At the same time as the first stage stolon seedlings are pregnant and differentiated, the axillary buds between the leaf axils produce new meristematic stolons. The axillary buds on the first node also remain dormant, and the growth points on the second node continue to differentiate leaf primordia. According to this rule, the stolon forms the 1st, 2nd, 3rd and 4th level stolon seedlings and meristematic stolon seedlings on the 2nd, 4th, 6th and 8th even-numbered nodes, and carries out multi-level network meristematic, resulting in a large number of stolon seedlings. The closer these stolons are to the mother plant, the better they will grow. Most of their top buds can form flower buds in the current year and blossom and bear fruit in the next year.Using stolons is a common method of seedling propagation in strawberry production. The number of stolons varies with varieties. Some varieties can sprout stolons many times in a year, and the number of stolons is more, while some varieties are not. Generally, cold varieties with high demand for low temperature, such as All-Star, Hani, etc., have less stolons; The varieties of warm ground that require short low temperature period, such as Baojiao Zaosheng, Fengxiang, Nufeng, etc., have more stolons.At present, strawberries are cultivated in plastic greenhouse in Jiangnan area. Due to the lack of heating equipment in the plastic greenhouse and the low temperature in winter, the growth of the top inflorescence is shorter, and the fruit shrinks under the plant. In addition, the poor ventilation and light transmission conditions in the greenhouse are easy to cause rotten fruit and cause economic losses. In order to promote the elongation of the top inflorescence of strawberry, make the fruit hang at the edge of the ditch, and reduce the rotten fruit, gibberellin was applied in production to promote the elongation of the top inflorescence, which has obvious effect.2. Regulation measures for the growth of stolon and inflorescence of grape(1) Promote stolon growth:In order to promote the occurrence of strawberry stolons, especially for varieties with few stolons, gibberellin can be sprayed. The method is to spray 50 mg/L gibberellin 1 to 2 times after the mother plant survives and grows three new leaves, and spray 5 to 10 mL per plant, which can effectively promote the occurrence of strawberry stolons and expand the propagation coefficient of seedlings.Yu Gengxu et al; The total number of secondary stolons was 18.7, which was 59.8% higher than that of water control; The secondary stolon occurred one week earlier than the control. In addition, GA3 can also relieve the inhibition of PP333 on strawberry, increase the number of stolons and petiole length of plants treated with PP333, and eliminate the inhibition of axillary bud development, but has no sustained effect on plant growth (Yang Huirong et al., 1993).(2) Inhibition of stolon growth:① PP333 sprayed with 250mg/L PP333 has obvious inhibitory effect on the length of stolon, plant height and petiole length of strawberry, and has an effect on increasing the yield of strawberry. It is worth noting that the inhibition effect of PP333 is too large. For example, after spraying with 500mg/L PP333 solution, it not only has extremely strong inhibitory effect on strawberry, but also can cause yield reduction. At the same time, until the fruit development period in May of the next year, there was still a large inhibitory effect, and the photosynthetic area was seriously reduced. Gibberellin has the effect of relieving the inhibition of paclobutrazol on strawberry. After spraying 20mg/L gibberellin solution on the leaves, it can take effect in about a week. After treatment with gibberellin, the strawberry seriously inhibited by paclobutrazol for a long time, the plant height was significantly increased, the petiole length was also significantly increased, and the growth potential was strengthened.(3) Promote terminal inflorescence elongationZhou Huayue (1997) experiment showed that after planting in the middle of September in the Fengxiang strawberry garden cultivated in the protected area, spraying 10mg/kg gibberellin once at the beginning of the bud emergence of the top inflorescence, and spraying once again 10 days after spraying, a total of two times, can significantly promote the elongation of the top inflorescence of Fengxiang strawberry, mature early, improve the early yield, and reduce rotten fruit. Compared with the control, the average length of the top inflorescence increased by 7.9 cm, the initial harvest date of fresh fruit was 13 days earlier, and the weight of fresh strawberry fruit in the early stage before the end of February increased by 44.6%. The number of fresh and rotten strawberries in the early stage (before the end of February) was only 8.5% of the control, with significant economic benefits.Section 3 Break dormancy and promote flower bud differentiation1. Strawberry dormancy and flowering physiologyAfter the flower bud differentiation of strawberry, under the conditions of lower temperature and shorter sunshine in late autumn and early winter, the plant enters into dormancy, with dwarfing morphology, small new leaves and short petioles. Although there are flowers and fruits, there are no stolons. The dormancy period of strawberry starts from a period of time after flower bud differentiation and gradually deepens, and generally reaches a deeper dormancy period in the middle and late November. After dormancy, different varieties need to experience different low temperature hours to break dormancy. The northern varieties have deep dormancy and need a long time of low temperature; the southern varieties have shallow dormancy or no dormancy and need a few hours of low temperature. Too many low temperature hours will lead to vigorous growth. Too many stolons occur and the result is bad. Varieties with low demand for low temperature are suitable for facilitating cultivation, and vice versa are suitable for semi-facilitating or open field cultivation. Long sunshine, high temperature or spraying gibberellin can break its dormancy. The above treatment can prevent it from entering dormancy and continue to blossom and bear fruit when it is about to enter dormancy; In the late stage of dormancy, the dormancy can be broken early and the growth can be resumed in flowering and fruiting.Strawberry is a short-day plant. Low temperature and short-day can induce strawberry to flower. Under natural conditions, strawberry can induce flower bud differentiation under night temperature of about 17 ℃ and sunshine of less than 12 hours, and flower bud can be formed after 9~16 days. Many studies have been done on the effect of hormones on strawberry flowering, among which there are many studies supporting the theory of "flowering inhibitory substances". The research results of Thompson and Guttridge showed that the higher the concentration of gibberellin, the longer the stem and petiole, the greater the occurrence of stolon, and the deeper the inhibition of flowering process. The effect was similar to that of long sunshine treatment. Ballinger et al. also proved the existence of gibberellin at the top of stolon and crown, and the gibberellin substances decreased at the stage of flower bud differentiation, and began to increase after the elongation of flower stalk. Hou Zhixia et al. (2004) believed that spraying gibberellin when some plants began to differentiate flower buds, while the other plants did not differentiate, and destroying the short sunshine conditions suitable for strawberry flower formation, could reverse the meristem of strawberry stem tip, return to the vegetative growth state, and could not form flower buds; Before that, when gibberellin was sprayed, the growth point could not turn into flowers, and flower buds could not form. The higher the concentration of gibberellin, the deeper the inhibition.2. Technical measures to break dormancy and promote flower bud differentiationAt present, gibberellin is used in strawberry production to release dormancy, promote development, increase yield and promote stolon occurrence. When gibberellin is used to treat strawberry to promote flower bud differentiation, the treatment period must be well controlled. It is better to treat strawberry at the beginning of growth point hypertrophy, which has no effect too early, and has side effects too late. Generally, the suitable period for treatment is from the germination of new buds to the development of flower buds. If it is too late or the temperature after treatment is too high, the rate of abnormal fruit will be high.Lu Junxia et al. In addition, spraying 50mg/L gibberellin when the growth point is fat at the early stage of flower bud differentiation can make Futian blossom one week earlier; If it is treated in advance, it will not have this effect, but after treatment, it will produce deformed fruit, or make the fruit stem excessively elongate. Shen Xiaoli et al. (1996) showed that the best time to inhibit strawberry dormancy and promote flowering was after the flower bud differentiation of the second and third order flowers when using gibberellin to promote early ripening of strawberry. Generally, the strawberry is sprayed from the end of October to the beginning of November, with a better concentration of 10mg/L, which can make the strawberry maintain a better plant height of about 20cm at the beginning of harvest, and the harvest period is 20 to 30 days ahead of schedule, and the yield and quality are in a better state.According to the investigation conducted by Wang Zhonghe (2007) in Shandong, ① in the semi-accelerated cultivation of strawberry, spraying 8~10mg L gibberellin at the early stage of growth has the effect of long sunshine, which can promote the development of flower buds and make the first inflorescence blossom early; It can promote the elongation of petiole and increase the three-dimensional photosynthetic space; It can promote the elongation of flower stalks and facilitate pollination and fruit development. ② In the accelerated cultivation of strawberry, early heat preservation and gibberellin treatment have the effect of inhibiting dormancy, and generally spray gibberellin 5~10mg/L for 1~2 times after the beginning of heat preservation. Spraying for the first time at the stage of 2 undeveloped leaves can promote the growth of young leaves and prevent dormancy; Spraying twice at the bud stage can promote the elongation of flower stalks and facilitate pollination and fertilization. When applying gibberellin on strawberries, we must pay attention to: the concentration should not be too high, the dosage should not be too large, 3~5mL per plant is enough, and the wine should be sprayed on the heart of the seedlings; The concentration varies with the variety. The varieties with shallow dormancy use less than those with deep dormancy, and the cold ground uses less than those with warm ground, and the number of times is also less. The varieties with deep dormancy, such as Dukara and Baojiao Zaosheng, can use 10mg

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2023-01-29

Classification of wheat varieties: according to different sowing seasons, wheat can be divided into spring wheat and winter wheat. According to the different color of wheat grain, wheat can be divided into red wheat and white wheat, which are called red wheat and white wheat for short. According to the different grain quality, wheat can be divided into hard wheat and soft wheat, which are called hard wheat and soft wheat for short.The Life of Wheat（1） During the growth period, wheat undergoes a series of growth and development processes from seed germination, seedling emergence, rooting, leaf growth, jointing, booting, heading, flowering, and seed setting to the generation of new seeds, which is called the life of wheat. The number of days required from sowing to maturity is called the growth period. The growth period of wheat is generally 190~210 days.（2） According to the growth characteristics of wheat at different stages, in order to facilitate cultivation and management, the life of wheat can be divided into 12 growth periods, namely, seedling emergence, trefoil, tillering, overwintering, turning green, rising, jointing, booting, heading, flowering, filling and maturity.（3） According to the characteristics of wheat organ formation, several continuous growth stages can be combined into a certain growth stage. Generally, it can be divided into three growth stages.1. The seedling stage is from emergence to start. It mainly carries out vegetative growth, that is, long roots, long leaves and tillers.2. The middle stage is from the start to the flowering stage. This is a stage in which vegetative growth and reproductive growth go hand in hand. There are root, stem and seasonal growth, as well as ear differentiation and development.3. The later stage is from flowering to maturity. Also known as grain formation stage, it is mainly reproductive growth.Soil, water, nutrients, temperature, light and air are the necessary environmental conditions for wheat growth and development. To achieve high yield of wheat, on the one hand, we should select excellent varieties according to local conditions, on the other hand, we should create environmental conditions suitable for wheat growth and development through field management.1. Land selection and preparation is the basisSoil fertility is the basis for achieving high yield of wheat. Only by selecting an environment with good soil fertility and sufficient topsoil thickness can high-quality wheat be planted. At the same time, when selecting the land, it is necessary to clean the previous stubble, and then plough deeply in time, so as to make sure that the top is empty and the bottom is solid, so as to facilitate the seed germination and root stability. If necessary, certain drugs can be added in deep ploughing to prevent pests in advance.2. Seed selectionSeed is the main factor to increase yield, and improved seed is the internal cause of yield increase, and is the basis for the development of agricultural science and technology. In the selection of seeds, we must combine the local soil conditions, select seeds with high yield, stability, quality, lodging resistance and high productivity, and pay attention to varieties with good economic benefits and early maturity.Before sowing, we should choose a good weather for about a week to sun the seeds, which can not only prevent mold and insects, but also improve the germination rate and promote the yield. Air drying once a month and 10 days before sowing will reduce the rate of insect erosion and increase the germination rate.In addition, seed dressing is also necessary. Seed dressing is the measure of mixing fertilizer, pesticide and wheat seeds in a certain proportion, and then mixing them repeatedly to make the fertilizer and pesticide evenly adhere to the surface of the seeds. The amount of seed mixing is small, the operation is simple, and the effect is good. For diseases and insect pests transmitted by seeds, seed dressing has almost become the only control measure, which not only eliminates the seed carrier, but also protects the seedlings from infection.3. Seeding managementAccording to the specific local conditions, select a better farming mode. According to the specific situation of the year, sow in time at the sowing time, and select a better sowing amount according to the soil and weather conditions. Generally, due to the poor soil conditions in the middle field, the planting amount can be appropriately increased, and the goal of increasing yield can be achieved by increasing the number of main stems and ears as much as possible. If it is a high-yield field, it is unnecessary, as long as it is carried out according to the normal seeding rate. If it is too much, it will easily reduce the permeability, reduce the individual growth ability, and then lead to lodging and reduce the yield. In a word, the amount of seeding is the key to establish a reasonable population structure. There must be certain differences in seeding amount with different varieties. The depth of 3-4 cm is better. Such seeding can ensure the seedlings are neat and strong, and then promote the yield and achieve the purpose of increasing income.4. Strengthen field managementFirst of all, from seedling emergence to tillering, wheat mainly grows leaves, roots and tillers. After seedling emergence, seedlings should be thinned at the first time to improve the uniformity of seedlings. If the weather is too dry, water it in time to ensure that the wheat can take root at the first time, tiller in time, improve the growth ability of the seedlings and strengthen the cold resistance of the wheat. For the wheat field with weak growth, the tillering fertilizer should be applied in time during the overwintering period. Generally, urea is the main fertilizer. If the fertilizer is not applied in time, the fertilizer should be applied in time in the next spring to promote rooting and tillering.The amount of water for winter irrigation of wheat should not be too large. It is better to be able to water thoroughly and completely on the same day. Generally, 30-40 cubic meters of water are irrigated per mu. In order to save water, it is necessary to complete the ditch and border to prevent flooding. After winter irrigation, timely hoe and loosen the soil to close the cracks, so as to maintain moisture and increase temperature.Prevention and control of dead wheat seedlings in winter: remove dead leaves and increase photosynthesis; Topdressing nitrogen fertilizer to promote rejuvenation; Water timely according to local conditions; Foliar fertilization to supplement nutrition; Cultivate and hoe, increase temperature and keep moisture.Secondly, when it comes to the jointing stage and the late growth stage of wheat, nitrogen fertilizer should be applied again. If the weather is dry, irrigation and fertilization should be combined to achieve better results. However, if the planting area is large and the seedling condition is relatively prosperous, it is necessary to delay the application of fertilizer to the late jointing stage, but it is necessary to reduce the amount of fertilizer properly. At the same time, for some fields with relatively good terrain, some herbicides should be added appropriately to remove weeds in time, so as to ensure the nutrition of wheat seedlings and promote the improvement of yield.The heading and flowering period of wheat is the key period for the formation of wheat yield and the peak period for the occurrence of diseases and insect pests. During this period, attention should be paid to the prevention and control of diseases and insect pests such as scab, stripe rust, powdery mildew, aphid, etc., to reduce the damage of plant diseases and insect pests, and lay a foundation for the later high yield of wheat.The head blight harms the ear of wheat: it causes the half-cut and withered ear of wheat, and the ear of wheat turns red when the field humidity is high; It is recommended to use triadimefon · tebuconazole, cyanoxylate, cyanene · hexazol and other chemicals for prevention and control.Thirdly, when the wheat grows to the filling stage, it can be sprayed with 1% - 2% urea solution. If the phosphorus and potassium elements in the soil are insufficient, 0.2% - 0.3% potassium dihydrogen phosphate solution can be appropriately increased to ensure the demand of plants for trace elements.Later, in the later stage of management, the main concern is the weeds in the field. Many weeds can not reach the goal through manual removal. Therefore, the grower should analyze the factors such as the type of weeds in the wheat field and select a better herbicide. The weeds in the wheat field are mainly monocotyledonous gramineae. For this kind of weeds, the main herbicides can be used, such as pygmalion, chlorpyrifos and isoproturon. For some plots with relatively more weeds, butachlor and trifluralin can be mixed and sprayed; If there are many broad-leaved grass in the plot, use good to eliminate it. In addition to the selection of herbicides, attention must also be paid to the humidity of the environment when using herbicides. Generally, it is better to keep the temperature above 10 ℃ after water. Try to spray when the seedlings are relatively small, so as to achieve the purpose of weeding, improve the cleanness of the wheat field, and promote the yield.5. Management of harvest period(1) Water the wheat straw wellAfter the waxy ripening of wheat, proper water supply can prolong the life of functional leaves, strengthen the accumulation and operation of photosynthetic products, especially in the rainy years, it is more important to water the wheat yellow water well, which can not only prevent the dry heat wind damage in the later period, but also promote the 1000-grain weight. According to the survey structure, the yield can be increased by about 10% by watering the wheat yellow water. Generally, watering the wheat yellow water after the wheat falls yellow can prevent late ripening. At this stage, the head of wheat spike is heavy, but we must pay attention to the weather conditions. If we encounter strong wind after watering, we can easily fall down. We must ensure that there is no strong wind in a day, and at the same time, we must control the amount of watering, not too much.(2) Grasp the exact harvest dateThe harvest season is when the wheat enters the late stage of waxy ripening. At this time, the wheat color turns yellow, the stem is elastic, the grain moisture content is also high, and the hardness is good and shiny. Another key step is to remove impurities. Only after removing impurities can the wheat reach a certain purity and achieve real high yield.

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2023-01-29

Maize, the largest grain crop in China, is a kind of C4 plant in the biological range, but its bracts use C3 mode for photosynthesis. It is monoecious, and its main production area is located in the world's third largest corn belt - the Songliao Plain corn belt in China. The total planting area of maize is about 1249.35 square kilometers, also known as maize, corn (corn cob), corn, and stick. It is called millet in Cantonese and parva in Minnan. It is an annual grass herb, an important food crop and an important feed source, and also a food crop with a high total yield in the world.1、 Type of cornCorn is mainly divided into spring corn and autumn corn according to planting season. It can be divided into common corn, sweet corn, waxy corn, bamboo shoot corn, high-oil corn and popcorn according to its use.2、 Site selection, preparation and application of sufficient basic fertilizer1. Site selectionRice is a crop that likes fertilizer and water, is warm and warm, needs more oxygen and is afraid of waterlogging. Too acid, too sticky and poor soil will make maize grow poorly. Therefore, it is advisable to select loam or sandy loam with convenient drainage and irrigation, convenient management, PH 6.5-7 and medium fertility.2. Land preparation and basic fertilizer applicationGood soil preparation is the prerequisite for preserving seedlings. After selecting the land, carry out deep ploughing and raking. Generally, two ploughs and two rakes should be carried out, and the depth of the tillage layer should be more than 30 cm, so as to meet the quality requirements of "flat, fine soil, sufficient moisture and high fertilizer". After land preparation, set out and open the ditch according to the double-row planting spacing of 120~140 cm, and apply 1000 kg of decomposed farmyard manure, 50 kg of bean cake and 50 kg of superphosphate as basic fertilizer strips in the ditch; In order to facilitate drainage and irrigation, ditches should be opened for border in combination with land preparation, and drainage ditches should be built on all sides. The border shall be flat and the ditches shall be straight, the ditches shall be connected, and the drainage and irrigation shall be smooth.3、 Seed treatment and sowing1. Select good varietiesThe suitable varieties should be high and stable yield, good quality, disease resistance and lodging resistance, and can meet the market demand and sell well. At present, "Yedan 4", "Yedan 13", "Zhongdan 321" and other varieties are selected for feeding corn. Special varieties such as "Tiannuo 1" and "Suyu 1" are selected for fresh corn. Generally, the seed consumption per mu of direct seeding field is 1500-2000 grams.2. Seed treatmentBefore sowing, carefully screen the seeds with bright color, consistent size, full grain and high germination rate. Ensure that the purity of seeds is at least 98% and the germination rate is at least 85%. In addition, we should eliminate inferior seeds, such as those with mildew, rot and too small particles. Then the seeds are dried. Generally, a good weather is selected one week before planting to dry the seeds outdoors. First, the corn seeds are spread evenly, and the thickness is kept at about 5cm. Select a windward and sunny place to turn at any time, so as to ensure that each corn seed can be exposed to light and dry for two or three days. Then the seeds are coated. After drying the corn seeds, the seeds are coated two or three days before sowing. In this process, the seeds should be evenly stirred in a place with backlight and leeward. After the coating treatment, the corn seeds should be naturally dried in the shade, and then harvested for sowing.3. Seeding technologyFor corn, agricultural experts put forward "seven points depend on sowing and three points depend on management", which shows how important the quality of corn sowing has on the yield. During the germination of corn seeds, the soil needs to provide enough water. Generally, the water content suitable for seed germination in the soil needs to reach 70% - 75%. When sowing in spring, if the seeding layer is shallow, the soil above the seeds will lose moisture when it is time for seed germination after 10 days. Once the seeds cannot absorb enough water, they will "dry seed". This will lead to the lack of seedlings and ridge cutting of corn, and reduce the yield. If the planting plot has good watering conditions, the soil moisture can be properly watered before sowing according to the soil moisture content, so as to ensure that the soil has sufficient moisture before sowing, so as to ensure the germination and emergence of seeds. If there is no better watering condition, we should seize the opportunity to sow seeds in time after the rain. During the seeding process, wet soil should be selected, with a depth of about 3.5-4.5 cm, so as to achieve the goal of preserving seedlings at one time and achieving full and strong seedlings.  4、 Scientific fertilizationIn the process of fertilizing corn, the principle of "light in front, medium in weight, and supplement in the rear" should be followed. Corn has a large demand for nitrogen, phosphorus and potassium. The absorption of the three elements in the whole growth period is more nitrogen, followed by potassium, and less phosphorus. Therefore, the fertilization of corn is mainly to increase nitrogen fertilizer, combined with phosphorus and potassium fertilizer. Generally speaking, the seedlings (1~6 leaves) grow slowly, the plants are small, and the nutrients absorbed are also small. At this time, the amount of fertilizer should account for about 10% of the amount of fertilizer. The growth is very fast from jointing to flowering (7~16 leaves). At this time, it is the formation and development period of male and female panicles. The nutrient absorption rate is fast and the quantity is large. It is the critical period for the plant to need nutrients. At this time, sufficient nutrients can be supplied to promote the number and size of panicles. At this time, the amount of fertilizer should account for about 60% of the total amount of fertilizer, and the absorption rate gradually slowed down in the later stage (after 17 leaves), and the amount of absorption also decreased. The amount of fertilizer should account for about 20% of the total amount of fertilizer. The application ratio of nitrogen, phosphorus and potassium is generally about 3:1:2.8. At the seedling stage, potassium fertilizer, organic fertilizer, phosphorus fertilizer and zinc fertilizer can be applied at one time. For phosphate fertilizer, it must be applied deeply, and the effect of increasing yield is obvious when the depth is about 15 cm.1. Management of seedling stageThe seedling stage of maize is the vegetative growth stage formed by rooting and leafing, stem, node and leaf differentiation, and most of the root system is formed at this time. The main goal of seedling management is to promote root development, cultivate strong seedlings, achieve complete, complete and strong seedlings, and lay a good foundation for the growth of the spike and grain stage.(1) Seedling fixation and thinning: master the principle of "removing the weak and keeping the strong, keeping the dense and thin, orienting, keeping the even and keeping the strong seedlings". Seedling fixation is generally carried out when five true leaves are left, and one strong seedling is left in each hole. At the same time, the seedlings are checked and repaired, the seedlings are moved with soil, and sufficient rooting water is poured to ensure the survival of the seedlings. If there are too many seedlings missing, it can be solved by replanting seeds.(2) Inter-tillage and weeding: maize seedlings can be inter-tillage for 1-2 times, combined with fertilization and proper soil cultivation. The depth of intertillage shall be shallow beside the seedlings, deep in the row, shallow before and deep after seeding, and pay attention to the prevention and control of diseases and pests.(3) Water and fertilizer management: at the time of 5~6 leaves, apply seedling fertilizer for the first time, apply 7.5~10 kg of urea per mu, open a ditch in the middle of the border, and then cover the soil. In case of water shortage in the seedling stage, irrigation should be carried out in time, and ditch irrigation is appropriate. In case of rainy days, wet soil and ponding, pay attention to open deep ditches to drain ponding and improve soil ventilation conditions.2. Management of ear periodThe goal of field management at the ear stage is to attack the stem and ear, prevent water and fertilizer deficiency, and make the plant neat, the stem nodes thick and short, the leaves wide and thick, the root thick and large, and the female and male ear develop well.(1) Water and fertilizer management: at the time of 8~9 leaves, the second topdressing, that is, the application of straw fertilizer, accounts for about 25% of the total amount of fertilizer, and 10 kg of Hefei compound fertilizer plus 7.5 kg of potassium chloride per mu is applied in the form of strip fertilizer. At the time of 14~15 leaves (big bell stage), the third fertilizer application, that is, the application of spike fertilizer, accounts for about 35% of the total amount of fertilizer application. Each mu of fertilizer is applied with 20 kg of compound Hefei and 10 kg of potassium chloride, combined with large soil cultivation. After 9 leaves and 15 leaves, topdressing outside the root was carried out once, and 50 grams of rare earth or 800~1000 times of potassium dihydrogen phosphate were sprayed per mu. From jointing to heading, the plant of maize starts to grow vigorously and needs much water, especially before and after heading, which is the critical period of water demand for maize. At this time, water shortage, poor development, inconsistent flowering of male and female, affect pollination, resulting in bald head, lack of grain or empty stem, so soil water capacity should be kept at 70~80% during this period. In areas with plenty of rain, attention should be paid to ditch drainage. The damage period of corn borer is from the bell mouth to the heading stage. It is necessary to spray 500~800 times of trichlorfon or a mixture of chlorpyrifos+Bt powder to control the corn borer.(2) Inter-tillage and soil cultivation: in order to prevent soil hardening, eliminate weeds, improve the growth function of root system, and promote the multiple and deep roots, the tiller and soil cultivation should be carried out according to the soil and weed conditions at the heading stage. Generally, 1~2 times of intertillage shall be carried out between jointing and heading, and 2~4 inches of deep intertillage shall be carried out between rows to cut off some hairy roots, stimulate multiple new roots, and enhance the ability of drought resistance and lodging resistance. In the "big bell mouth" period before tasseling, plough once more shallowly and raise the soil ridge.3. Management of heading and fruiting periodThis period is the key period to determine the number of effective panicles, the number of solid grains per panicle and the grain weight. At this time, we should mainly pay attention to the appropriate amount of fertilizer supplement (10 kg of urea), drought resistance and drainage, artificial pollination and other work. When heading, flowering and grouting, irrigation should be carried out in time to keep the soil moist and meet the water requirements of the plant. However, irrigation should not be flooded, and it is better to irrigate horse water. Pay attention to drainage in rainy days to avoid waterlogging and anoxic injury to roots. During the flowering period of corn, in case of bad weather, artificial pollination should be carried out for 2-3 times, usually at 9-11 am on sunny days, to reduce the lack of grain and baldness.5、 Pest controlIn principle, prevention should be given priority to comprehensive prevention and control, and early detection and prevention should be carried out in management.The prevention and control of aphid diseases can be achieved by seed dressing. Dwarf disease, commonly known as the Clivia phenomenon, is caused by underground pests that damage the roots, and then infect the virus. Once the disease occurs, it will almost disappear. The control method is to mix seeds with carbofuran seed coating agent. The dosage of carbofuran is 20%, and the low value should be greater than 7%, but less than 7% has no effect. Yellow seedling disease, corn seedling disease, underground pests damage the taproot, and then infect the bacteria, which are often mistaken for top rot. Once the disease occurs, The production reduction is serious. The prevention and control method is to use carbofuran seed coating agent to mix seedsMaize diseases mainly include leaf spot, rust and sheath blight. Insect pests mainly include corn borer, armyworm, corn aphid, cotton bollworm, small land tiger, etc. For chemical control, large and small leaf spot and rust can be sprayed with 500 times of 50% carbendazim, and sheath blight can be sprayed with 500 times of 5% jinggangmycin. Corn borer and armyworm can be sprayed with 10% cypermethrin 2000 times and Bt powder 800 times, corn aphid can be sprayed with 20% Kangfuduo 3000 times, cotton bollworm can be sprayed with Bt powder 800 times and Tianli powder 800 times.

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2023-01-29

Rice lodging is a difficult planting problem in the process of rice planting management. Because rice is prone to extreme weather such as strong wind and precipitation in the later stage of growth, once lodging is caused, it will affect the yield in the later stage. Therefore, we must pay attention to the problem of rice lodging in the process of rice planting and management.1、 Causes and solutions of lodging1. The field is not sunned in time, the field is not sunned in place, and the root system cannot be well planted, resulting in the root system is not firm and prone to collapse.2. Inappropriate management of water layer and long-term deep water condition of rice resulted in soft stems, long basal internodes and reduced root hypoxia resistance.3. The planting density is too large, resulting in dark fields and thin stems; The transplanting depth is deep, the tillering node is high, the seedlings are long and easy to collapse.4. The main reason for unreasonable fertilization is that too much nitrogen fertilizer is applied too late, the stems are thin and weak, and prone to lodging.5. The occurrence of serious diseases and insect pests is prone to lodging; Disaster weather such as hail caused rice to collapse.In order to reduce the probability of rice lodging, measures should be taken such as reasonably controlling the water content of the rice field, timely sunning the field and putting it in place, reasonably controlling the density of seedlings and not too deep, controlling the amount of nitrogen fertilizer, and timely preventing and controlling diseases and pests. The important measure to prevent rice lodging is chemical control of rice, that is, plant growth regulator control. The chemical control of rice must be used from the early stage of tillering to the early stage of jointing according to the growth trend in the field, and the appropriate dosage must be mastered.Calcium tranexate: the rice chemical control agent is Quanfengshi Bida, and the effective ingredient is 5% calcium tranexate. Shipida is a new generation of chemical control and production increasing agent of Quanfeng Company, which has the characteristics of high activity and no residue. The effervescent granule dosage form makes the drug use more environmentally friendly. On the one hand, calcium cyclamate can reduce the length of internode, dwarf the height of plant base, increase the mechanical strength and improve the lodging resistance of rice; On the other hand, it can reduce the rate of shrunken grain and increase the number of solid grains, thus increasing the yield per unit area. Tranexate calcification solves the contradiction between lodging resistance and high yield of rice. On the premise of ensuring a certain plant height and planting density of rice, it can promote the filling of inferior grains of rice, improve the lodging resistance and yield increase ability of rice from the biological characteristics, so as to achieve the purpose of cultivation regulation.Advantages of calcium cyclamate compared with triazole control products:1. High activity of leaf surface absorption2. Short half-life, low toxicity and no residuePaclobutrazol: use 100~133 g of 15% paclobutrazol wettable powder per mu, add 100 kg of water to prepare paclobutrazol solution with a concentration of 150~200 mg/L. Spray the stems and leaves with the prepared solution before jointing, which can shorten the internode, thicken the stem wall, develop the mechanical tissue, and effectively prevent lodging.CCM: At the beginning of jointing, 50~100g of 50% CCM water solution and 50 kg of water per mu are added to prepare the concentration of 500~1000mg/L of CCM solution. Spraying on the stems and leaves can make the rice plant short and strong and prevent lodging.Ethephon: For late-season rice seedlings, spray 40~50 kg of Ethephon solution with a concentration of 3000 mg/L on the leaves per mu, or spray 50 kg of Ethephon solution with a concentration of 1500 mg/L on 20~30 days after planting in the field, which can effectively inhibit the growth of plant height and increase tillering after treatment.2、 Principles of rice chemical control:The main role of rice chemical control is to reduce the spacing of 1-3 nodes at the base. The formation period of the base node is the tillering stage of rice. At this time, the application of pesticide can shorten the length of the base node, increase the thickness of the base node, dwarf and take root, and promote the absorption of water and fertilizer; Promote the formation of silicified cells in rice, improve the flexibility and strength of stems, and effectively improve the lodging resistance of rice in the later stage. At the same time, it can also increase the effective tillering quantity, reduce the ineffective tillering, make the leaves dark green, improve the photosynthetic efficiency, strengthen the plant, coordinate the transformation from vegetative growth to reproductive growth.3、 Mistakes of rice control:Rice chemical control is an important measure to prevent lodging, which is widely used in rice production. However, there are some misunderstandings in actual production. One is that people are blind to the selection of chemical control agents. The second is that people mistakenly believe that the shorter the rice is, the better the rice is. The stems and leaves of plants are the source of organic matter production and yield formation, which is called the source of plants. The ear of rice is the storage organ of yield, which is called the sink of rice. This is the source-sink theory. The source and sink promote and restrict each other. The source and sink promote each other, and the sink promote the source. The source and sink can not have the output that can only be achieved through harmonious development. If we blindly pursue rice dwarfing, then the source of rice cannot be guaranteed, affecting the high yield of rice. The chemical control of rice can shorten the internode 1-3 at the base, thereby reducing the plant height, enhancing the flexibility of the stem, promoting rooting, increasing the effective tillering, and promoting the transformation from vegetative growth to reproductive growth. This is our original intention of chemical control of rice to prevent lodging, not to blindly reduce the plant height.

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