First, select resistant and resistant varieties and secondary coating
Dense-tolerant varieties not only have a high yield potential, but also the basis for safe and productive production. Although the history of modern corn breeding and cultivation has been a hundred years old, the yield gains of intransparent breeds have not changed much in comparison with the past, and the promotion of compact and compact varieties has only substantial improvement in the level of corn production. Contributions. The successful high-yield technology Tian Quan uses high-density planting of density-resistant varieties, but the suitable density is less than 4000 plants/mu, which is generally not of high potential.
The range of density density density tolerance is also relatively wide. If the density density of insensitive varieties is large, lodging, poor solidity and other problems will occur. At present, among the high-yield varieties with medium plant heights, Zhengdan 958 and similar varieties such as Fufeng 223 and Wuke 2 are preferred. Although Shandan 20 has a higher yield potential than Zhengdan 958 when the weather is favorable, the stalks are soft and easy to break; Xianyu 335 has good toughness but is easily rooted before pumping. For similarly defective varieties, large-scale growers choose varieties. Be careful. At present, there are also some dwarf and stable yielding varieties. Many of these varieties are due to their denseness, resistance to lodging, or early maturing. Large planting families may also consider the selection when they are planted. After all, compactness, early maturing, and rapid grain dehydration are the future scales. Planting, full realization of the characteristics of varieties that are necessary for mechanized harvesting and even grain harvesting. In terms of disease resistance, when selecting seeds, we must focus on whether it is resistant to diseases such as Fusarium stalk rot and Pythium stalk rot and sheath blight that can infect stems.
In recent years, in the wheat-maize two-cropping area, due to the continuous planting system for successive years, Fusarium, Pythium, etc. have accumulated in the soil year after year, causing root rot, head blight, root rot and stem rot in wheat. Upward trend. Due to the low incidence of head smut in summer corn, many of the commercially available coating seeds in summer sowing areas, in order to control the cost, seed coating agent ingredients are mostly pesticides, no fungicides, which give corn root rot, In particular, the chances of late stalk rot (wild wilt, yellow bacterial blight) re-introduction provide opportunities, and plants with stem rot are susceptible to lodging before harvest.
At present, there are no anti-pyrumycete antigens on corn in China, such as Zhengdan 958 and Qidan 20 are moderately susceptible varieties. To prevent stalk rot, chemical control should first be treated with a bactericide for seed treatment. Because some common bactericides (mainly triazoles) can cause phytotoxicity due to excessive treatment of seeds, peasants' friends must know whether or not to use the bactericide when buying seeds. The agent was coated twice and tebuconazole, diniconazole, difenoconazole, fludioxonil, and thifluzamide were all available. The latter three were relatively safer. Treating seeds with triazole fungicides should be strictly controlled within 0.1%-0.2% of the seed amount. Some insecticides and growth regulators also have a good root-preventing effect, which can be added together with secondary coating of fungicides. For example, the use of Brassinolide and Bayer's "Gao Qiao" (60% imidacloprid) seed dressing can stimulate the development of maize roots and improve lodging resistance.
Second, pay attention to the application of basic fertilizer to scientifically manage the supply of fertilizer and water
The short live period and rapid growth of the hot spring and summer maize seedlings, high soil fertility and sufficient base fertilizer make the strong seedlings grow early, which is a necessary condition for the formation of strong stalks and large ears. Yang Lihua's researcher pointed out that only when soil fertility is high or the amount of base fertilizer is sufficient, corn stalks will develop stoutly, and corn stem diameter has a very significant positive correlation with the yield per plant and the resistance to lodging of corn. In the simultaneous sowing of maize seedlings and the selection of base fertilizers, corn-specific compound fertilizers (or compound fertilizers) with a high nitrogen sufficient amount of potassium and phosphorus should be selected so that the nitrogen content is not less than 25% and the potassium content is not less than 10%. good. The application of potash fertilizer should not be neglected when applying base fertilizer. The yield of high-yielding corn requires higher proportion of potassium than low-yield corn. Potassium has obvious effects in improving drought resistance, lodging resistance and stem rot resistance in maize. When the general maize special compound fertilizer seed fertilizer is produced on the same seeding, the amount of mu sowing fertilizer must reach 15-25 kilograms, and the slow/controlled release fertilizer should be applied at the same time to avoid the top dressing technique. The mu sowing amount should be guaranteed to 35-40 kg.
The early stage of corn drought tolerance drought, early water control seedlings moderate to help prevent lodging. In the initial stage of jointing, it is necessary to avoid top-dressing with irrigation, prevent the growth of the internodes of the base, and prevent the plant height and ear position from getting out of control. After entering the rainy season in the middle and later stages, irrigation needs to be done while watching irrigation. The weather forecast for the next week, re-watering in the absence of rain, and storms after pouring, can easily cause lodging. In fact, in the case of high fertility of the soil or underfoot fertilization, corn does not need to be top-dressed during the period of jointing to large bell-mouths, and the use of flower-promoting methods to increase yield should be followed by dressing after the big bell-mouth period, with a focus on improving seed setting rate and preventing Late defermentation of premature aging, to ensure that the weight can be further to obtain high yield. The use of slow/controlled release fertilizers with one-time application of top dressing technology can eliminate the need for top-dressing and top-dressing watering. Naturally, it also avoids the problem of rainstorm lodging after top-dressing.
Third, the use of scientific planting style pay attention to reasonable dense planting
Planting styles are plant spacing arrangements, there are equal spacing, size ridges and hole sowing, etc., and there are different row spacings in the row spacing. For densely planted summer maize populations, narrowing the row spacing and increasing the plant spacing will help to make full use of resources such as nutrients, moisture, and light that are evenly distributed in the field, so as to relieve the individual interactions and fully develop individuals and form strong culms and spikes. Experiments have shown that the planting of rows of maize about 50 centimeters in the south-central area of ​​Hebei Province not only produces high yields, but also the mechanical development of the stalks is better than large row spacing, which is beneficial to resistance. In the case of mechanical harvesting, considering the harvester's need for harvesting, the corn spacing can be relaxed up to 60 cm (since the row spacing of the harvester is generally 65-70 cm). The ridges (35-40 cm + 70-80 cm) are slightly controversial compared to equal-row planting. The experiment was conducted on corn in southern Inner-eastern Jiangxi Province. The yield advantage was not obvious, but it was planted in large and small ridges. It is easy to implement the cultivator to prevent soil fallow. Cave sowing is “multiple planting in one caveâ€. In the past, it was used on hilly lands in the mountainous area. It can be used to obtain higher yields on the slopes where the soil layer is not suitable for mechanical operation and the method of concentrated fertilization is used for digging “high yield pitsâ€; in soil conditions In the better plain area, many plants are planted in one hole. Because the nutritional area of ​​each plant is too deformed, individual growth competition is fierce. If the soil fertility is generally insufficient or the base fertilizer is insufficiently applied, corn growth will be weak and easy to fall.
The relationship between planting density and lodging is extremely close, and rational dense planting is precisely ignored by many farmers. There are two main principles for rational dense planting. The density is determined by the variety and density by water and fertilizer conditions. There are recommended planting densities for each variety introduction. It is a comprehensive result that takes into account the adaptability of varieties and lodging resistance, and the scaled planting should be standardized in accordance with the recommended density. Among the compact varieties currently planted and planted, the high stalk varieties with a plant height of 290 cm or more, such as Xianyu 335 and Nonghua 101, are suitable for a planting density of approximately 3800 per mu, and 260-290 cm for middle plant heights such as Zhengdan. 958 and other suitable density in the 3800-4500 strains / acre, 260 cm dwarf varieties below 4500 / acre; semi-compact and flat variety usually only 3800 / acre. It should be noted that at present, the density of planted medium-high plants represented by Zhengdan 958, which is mainly planted in China, and summer sowing and safe high-yield, are at 4200 plants/mu, and the planting density reaches 4500 plants. After all, there is a risk of lodging. Water and fertilizer conditions are also the main factors to be taken into account in determining the planting density. Generally, the upper limit of the recommended planting density can be taken from a high ground force and a good water conservancy condition, and vice versa.
Fourth, we must be careful when selecting post-emergence herbicides
Researcher Yang Lihua pointed out that after weeding, the summer corns are sprayed with herbicides and chemically weeded them. Since they are usually used once every quarter, they basically replace the need for secondary herbicides with closed herbicides and mid-term paraquat. At present, there are many varieties of post-emergence chemical herbicides, such as nicosulfuron, 2,4-D, 2-methyl-4-chloro, mesotrione, oxacimone, rimsulfuron, etc., and some of their compound preparations. These varieties are detrimental to the lodging resistance of corn. For example, in some places 2,4-D and 2A-4-chlorophenol are used for the control of weeds and sedge weeds. When these two hormone drugs are applied late and in large quantities, the visual injury is caused by 10 leaves of corn. The leaves are not spread smoothly, and the plants are tall and thin, and the roots of the air grow into pods and are difficult to penetrate into the soil. The invisible phytotoxicity is to make the corn stalks brittle and easy to fold. Therefore, Yang Lihua's researcher believes that care must be taken when applying these two types of herbicides.
Mesotrione is also a harmful to corn. It will increase the plant height and ear position and increase the lodging rate by 2-3 times. Nicosulfuron is inexpensive, has a broad spectrum of herbicides, and has an inhibitory effect on plant height and ear position. As long as the appropriate period and appropriate amount of medicine are used, spraying the liquid spray into the mouth of the bell as much as possible can be used to control the harm of phytotoxicity. Corn resistance is still beneficial.
Fifth, the appropriate control of drop stalk
Since the end of the 1980s, the technology of control and prevention has been widely recognized and adopted. Yang Lihua's researcher pointed out: "This technology has also evolved from the initial application of large bells in the late stage of administration to early application of pesticides and the control of internode elongation. After all, stem cutting is the type of lodging that has the greatest impact on the yield of corn. Basal stem breaks usually occur. In the third and fourth quarters below, there are few fifth and sixth quarters.†For example, in 2013, the breaks in the internodes of the large area above the eastern part of Shijiazhuang were more rare. In order to control the internode elongation and reduce the ear position, the application of pesticides should not be too late, and the chemical control agents are all growth inhibitors. The application of pesticides will have an adverse effect on ear differentiation, resulting in small spikes, small grains, and baldness. . The currently effective chemical control agents such as Jindele and Teng Tianbao generally require 7-11 tablets to be applied when the leaves are visible, but most of the production is delayed. Tests have shown that the best time for spraying is corn growing to 5-6 leaflets, which is the beginning of jointing.
Six, cultivator soil
After the jointing of corn, the soil can be cultivated by the cultivator, and the effect of cultivating the soil is not only to remove soil compaction, improve soil permeability, eliminate weeds, promote the absorption of nutrients and water by secondary roots, but also to fix plants and prevent lodging, especially It is also very obvious that it is rooting. The domestically successful summer maize tonnage field uses large and small ridge planting patterns. Ditching the soil on both sides of the large ridge can immobilize the plants on the one hand to prevent lodging; on the other hand, the open channel is used as irrigation ditch, and the fields are not single. The ditch is designed to improve the land utilization rate. The cultivating soil in the cultivator is one of the traditional agricultural field management links characterized by intensive cultivation. Since the popularization of chemical weeding techniques in the late 1980s, the production of corn has gradually faded out. The medium-to-large cultivator + cultivation soil + fertilization comprehensive operation machinery in the country will be perfected. After that, this technology is still worth reusing.
Seven, timely prevention and control of pests and diseases
Insect pest damage not only reduces the ability to resist lodging by affecting the growth of corn, but also causes damage to corn mechanical tissue is also an important factor that makes corn easily pourable. In terms of controlling pests and diseases, in addition to the secondary coating mentioned earlier, during the maize trumpet period to tasselling period, it is important to control corn borer and bacterial stalk rot. After the tasseling, corn borer is one of the reasons that the straw wind breaks easily because of the drill collar damage to the stem. Therefore, an insecticide should be applied before tasselling to prevent the damage of the corn stem with the leaf blade. Bacterial stalk rot is not a serious hazard to maize in southern Yunnan, but some varieties, especially some sweet glutinous rice cultivars, may develop in hot and rainy years in summer, and the symptoms of susceptible plants are mainly rotted in the lower stem nodes. And cause corn lodging. For varieties that may be infected with bacterial stalk rot, we should select high-efficiency fungicides such as streptomycin or Jinggangmycin for controlling bacterial diseases in the rainy season, and focus on spraying the lower stem nodes. In the middle and later stages of grouting, it is important to prevent diseases such as stalk rot, sheath blight and sheath rot that can infect stems. Starting in late August, the plants were sprayed with 30% chlorobromoisocyanuric acid 1000 times or 50% procymidone 1500 times, spraying once every 7-10 days, even for 2-3 times.
Eight, to Xiong
A tassel was removed about a week after pulling males. Detasseling can not only improve the light conditions in the canopy, reduce the damage of the late locusts, increase production by about 7%, and it is also beneficial to the corn in later stages. After detasseling, the wind resistance of the plants was reduced, and the second was the reduction of the center of gravity. In 2009, Yang Lihua, a researcher at the 100-acre high-yield demonstration farm in Dianshang Village, Yucheng County, Shijiazhuang City, once dethronted after corn was loosened. After the decapitation, a storm was encountered. As a result, all the surrounding corn fell flat, and the 100 acres did not fall.
John Dory Fish,Frozen Fish Fillets,John Dory Fish Fillet,Cream Dory Fish Fillet Skin
Zhejiang Zhoushan Jiaze Aquatic Co., Ltd. , https://www.tianjia-aquatics.com