Planting technology of sweet corn 1, seed selection. Choose varieties suitable for consumers' taste, with relatively long picking period, good yield, appropriate sweetness, pure fragrance, soft texture, rich nutrition, uniform ear size, thin seed coat, yellow seeds, white ear axis, high seed germination rate, strong seedling vigor, good stress resistance and strong lodging resistance, such as Tianyu 2, 4 and 6 of China Academy of Agricultural Sciences.
2. Sow in stages. In order to prolong the picking supply period and increase the benefit, we can adopt different cultivation methods, sow in stages and in batches, and match with early, middle and late-maturing varieties. Open field cultivation started in late March? Sowing can be done in early August, and greenhouse planting can be done early or late, usually in spring 150d, summer and autumn 10. 15d broadcast a batch, which can make the annual supply of sweet corn listed one after another.
3. Planting in isolation. Sweet corn must be planted in isolation to prevent hybridization with other corn varieties, reduce sweetness and affect quality. No matter what kind of sweet corn is planted, it must be planted in isolation, the isolation area should be above 400m, or the time difference can be used, and the flowering period should be more than 30 days apart.
4. Fine seedling raising. Sweet corn seeds wither, the ability of germination and topping soil is poor, the germination rate is low, the seedling growth potential is weak, and the soil requirements are high. Generally, it is necessary to dig deep, rake flat and break fine to make the soil loose and have good water content, and create a suitable soil environment for seed germination and seedling growth. Seeds should be carefully selected to remove insect species, bad species and mold species. When sowing, the soil moisture should be suitable and the sowing should not be too deep. 5cm, at the same time, ensure the same depth of covering soil, and sow for 2? 3 capsules, strive for the whole seedling. Apply sufficient fertilizer between holes and pay attention to the prevention and control of underground pests. 50% phoxim can be used for seed dressing or root irrigation.
5, reasonable close planting, to ensure high yield spike number. For sweet corn, if the number of ears per mu is sufficient, the ear size is moderate and the ear type is good, the benefit will be high. General high-yield fields need 5000 plants per 667m2? 6000 strains.
6. Strengthen on-site management. Under the condition of general soil fertility level, 7.5kg of available potassium was applied every 667m2, and general phosphorus and potassium fertilizer was applied as basic seed fertilizer 1 time. Water management should pay attention to flood control in seedling stage and drought prevention in middle and late stage. Because sweet corn is slow to emerge, it is easy to lack grass at seedling stage, so weeds must be removed at the early stage of intertillage. Timely control of corn borer from jointing stage to big bell mouth stage. If we use drugs to control corn borer, we should be cautious, use less and use low-toxic pesticides such as phoxim early, which can not only effectively control pests, but also affect the quality of corn. Sweet corn is poured until it is cooked. If there are aphids, you can spray ears with BT emulsion. Pull out tillering seedlings in time during the whole growth period, and pay attention to intertillage weeding. Raising soil can promote growth, increase yield and fundamentally improve sweetness.
7, timely harvest. The harvest time of sweet corn directly affects the quality of fresh ears. Ordinary sweet corn 20? 28d, super sweet corn 18 after rotation? Harvest in 30 days. Harvesting is usually carried out in the early morning so that it can be put on the market or processed on the same day.
Isolation planting technology of sweet corn
Sweet corn should be planted separately from ordinary corn or other types of corn to avoid cross pollination. Both spatial isolation and time isolation are possible, but spatial isolation is better. If spatial isolation is adopted, the plain area is generally above 400m m. If there are natural barriers such as trees, hills, houses and highways, the isolation distance can be shortened appropriately. If time isolation is adopted, the sowing period should be more than 30 days apart. In short, the principle is not to let two kinds of corn pollen meet.
When planting sweet corn in the selected plot, it must be more than 400 meters away from ordinary corn or other types of sweet corn: if there are obstacles such as trees and hills, the distance can be shortened. If the cultivation distance of sweet corn is not enough, time isolation should be taken to avoid the two types of corn pollen meeting, and the sowing date should be more than 20 days apart. Sweet corn can be planted in two rows under the conditions of loose and fertile soil, wide irrigation and drainage border and rice, with a row spacing of 50 cm and a plant spacing of 32-36 cm, with seedlings per hole 1 plant.
Fine soil preparation
Because of the low starch content in sweet corn seeds, the ability of germination and soil arching is weak, so the plots with loose soil, good fertility, good water content and convenient irrigation and drainage should be chosen when planting. Popularize the use of soil tester to predict soil quality. In areas where conditions permit, 1000 ~ 1500 kg of high-quality decomposed manure can be mixed per mu, and 15 kg of calcium superphosphate can be added before sowing and fully mixed and matured. Sowing should be fine, 3 ~ 4 grains per hole, and the sowing depth is slightly shallower than that of ordinary corn, generally covering about 4cm.
Sowing by stages
Planting sweet corn is to sell fresh ears of corn in the market, or to supply canned food for processing in the factory, which is completely different from planting ordinary corn. At the same time, sweet corn cannot be stored for a long time after harvest. Therefore, planting sweet corn should be carried out in stages according to market demand and factory processing capacity, and the early, middle and late maturity varieties should be matched to improve economic benefits.
rational close planting
Planting density depends on variety characteristics, soil fertility, sowing date and planting method, and pay attention to the commercial performance of ear. Generally, 4,000 plants/mu is suitable for medium fertility soil, and the early-maturing varieties can be denser and the late-maturing varieties can be thinner.
Tiantuan management
Water in drought
In areas with irrigation conditions, irrigation should be carried out in time at seedling stage, big bell mouth stage and grouting stage.
Check seedlings, replenish seedlings, and fix seedlings at intervals.
Check and replenish seedlings in time after emergence; When the seedlings grow to 3-4 leaves, they are fixed when they grow to 4-5 leaves. The principle of seedling spacing is to remove the big, small and leave the middle to ensure the uniformity of seedlings in the whole field.
Pay attention to topdressing and timely intertillage
Generally, topdressing organic fertilizer or soil miscellaneous fertilizer 1000kg per mu, urea 30kg (topdressing kg at seedling stage and jointing stage, 15kg at big bell mouth stage) and potassium chloride 5 ~ 7kg；; Potassium fertilizer and organic fertilizer or soil miscellaneous fertilizer should be applied at seedling stage at one time. Top dressing should be applied in as deep a hole as possible, and the soil should be covered in time after application. After each topdressing, weeding should be done in intertillage, and attention should be paid to leveling and breaking loose during intertillage to avoid damaging seedlings.
Timely castration
Timely emasculation is the key cultivation technique to ensure high yield and high quality of sweet corn. But timely castration is the key to the success of the technique, and premature castration is easy to bring out the parietal lobe; If castration is too late and nutrition consumption is too high, the meaning of castration will be lost. When harvesting corn buds, when the tassels exceed the top leaves, they should be emasculated. The young ears of sweet corn should be emasculated 2 ~ 3 days after the tassels are scattered.
control of insect
Underground pests, phoxim kg and fine sand 25 ~ 30kg； can be applied per mu at seedling stage; For corn borer, carbofuran granules can be applied at the heart leaf stage or the end of the heart leaf stage.
Timely harvest
The harvest period of sweet corn has great influence on its commodity quality and nutritional quality. Premature harvest, less grain inclusions; If the harvest is late, the peel will harden and there will be more dregs, and the unique flavor of sweet corn will be lost. Generally speaking, the suitable harvest period is 20 ~ 23 days after ear pollination; Canned food can be harvested as early as 1 ~ 2 days, and fresh ears can be harvested as late as 1 ~ 2 days.
Sweet corn has strict requirements on production technology and harvest period, and its shelf life is short. China has mastered a set of breeding techniques and accumulated some germplasm resources, and all kinds of sweet corn types bred in China can basically meet the market demand.