What diseases are there in the seedling stage of longevity food corn? what kind of drugs are there? What are the key points of field management?

Corn is an annual monoecious pollination plant with tall plants and strong stems. It is an important food crop and fodder crop. So what diseases are there in the seedling stage of corn and what drugs are used? What are the key points of field management?

What diseases do corn seedlings have and what drugs do they play?

1. Yellow leaf seedlings

Harmful symptoms: the leaves of the seedlings are light green at first, then turn yellow gradually, and in severe cases, the whole leaves wither and die.

Prevention and cure method

① seed pre-sowing treatment. Pick out blighted grains, mildew grains, bad grains and small grains, and soak the seeds with seed coating or fertilizer and water.

② suitable time vaccine. The seedlings, weak seedlings, diseased seedlings and field weeds were removed when the corn was 4 leaves.

③ applied nitrogen fertilizer timely after maize seedlings.

④ if there is dry soil before and after the emergence of corn plots, gently remove the dry soil from the surface with a small wire rake and break it.

2. Albino seedlings

Harmful symptoms: there are white stripes on the leaves and serious whitening of the leaves of the whole plant. The cause is lack of zinc in the soil.

Prevention and cure method

① mixes 10-15kg fine soil with 1kg zinc sulfate evenly and sprinkles it next to the seeds when the corn is sown.

② sprayed the seedlings with zinc deficiency with 0.2-0.3kg zinc sulfate and water 100kg per 667m2, once every 7 days, only 2-3 times to make the seedlings return to normal.

3. Stiff leaf seedlings

Harmful symptoms

Mainly appeared before the seedling 3-leaf stage, the seedling plant shape is small, the leaf is light green, the black root is many, after transplanting, except the new leaf is green, the outer leaf is yellow and stiff, the stress resistance is poor, easy to appear dead leaf, dead seedling.

Prevention and cure method

① seedling stage is mainly mature organic fertilizer, do not or less use urea as base fertilizer, phosphate fertilizer must be retted after application, the soil to maintain a proper temperature, strong seedlings to transplant.

For the stiff seedlings that have already appeared, ② should strengthen the watering and foliar spraying of corn in time, and use foliar fertilizers such as Gaomeishi and sunflower.

4. Red leaf seedlings

Harmful symptoms: the seedling grows slowly, the leaf is small, the root system does not decline, and the leaf color turns red gradually.

Prevention and cure method

① is suitable for sowing.

Covered with ② plastic film.

The transplanting of ③ corn was carried out in sunny days.

④ uses hoes to loosen low-lying, clayey land.

What are the key points of field management in maize seedling stage?

The stage from sowing and emergence to jointing is the seedling stage. The seedling stage of corn is about 20 rain for 30 days. Maize seedling stage is mainly long root, leaf increase, stem and leaf differentiation, which determines the number of leaves and nodes. The main goal of seedling management is to promote root and seedling, strive for seedling integrity, seedling strength, and lay the foundation for high yield. At present, the planting of spring corn in our county has been completed, and the corn is in the stage from emergence to just emergence. The management measures for the emergence of corn are as follows.

1. Check and replenish seedlings

Maize seedlings should be checked and replenished immediately after emergence. Before the three-leaf stage of maize, it is found that there are more than 3 consecutive seedlings (holes), so the seedlings should be replenished in time, and the method of transplanting seedlings with soil can be adopted to reduce the difference of seedling potential among plants. Transplanting should be carried out in rainy days or sunny afternoons, and watering should be carried out in time after planting to shorten the slow seedling time and ensure survival. If there are less than 3 seedlings (holes), leave two plants on one side or both sides of the missing seedlings, and replanting of corn seedlings is generally not recommended.

2. Interseedling and fixed seedling

Suitable time seedlings and fixed seedlings are the key to reduce the rate of weak plants, improve population uniformity and ensure suitable density. Corn grows fast, so it should be timely and early to plant and fix seedlings. Generally master 1-2 leaves of time seedlings, 2-3 leaves when fixed seedlings. The principle of inter-seedling is to get rid of weak seedlings and leave strong seedlings, and get rid of diseased seedlings to keep healthy seedlings. The time of inter-seedling and fixed seedling should be carried out in the afternoon of sunny day, because at this time, diseased seedlings, insect bites and stunted seedlings are easy to wilt and easy to identify and eliminate. The seedlings with dense dwarf leaves, thick at the bottom and fine at the top, and twisted silk and black spikes should be removed thoroughly. In dry land and plots with low production level, seedlings should be planted early and fixed. The distance between the two seedlings was 5-10cm when the seedlings were retained. Interplanting corn has many insect pests, many disabled seedlings and heavy grass damage, so it is difficult to protect seedlings. Generally, 2 time seedlings with unfolded leaves and 3-4 leaves with fixed seedlings.

3. Ploughing and stubble elimination

Intertillage is an important measure for maize seedling management. The principle of intertillage is: shallow ploughing next to seedlings and deep ploughing between rows. The seedling stage of direct seeding plastic film corn is in the dry season, so it is necessary to shallow ploughing, lest the ploughing is too deep and hurt the root system. After interplanting corn and wheat harvest, we should immediately plough and destroy stubble, loosen the soil and promote the development of root system.

4. Topdressing and extracting seedling fertilizer

Topdressing at seedling stage has the functions of promoting root, strong seedling, promoting leaf, strong stem and so on. Generally, it is carried out from the seedling setting to the jointing stage. The specific time of topdressing should be determined according to seedling condition, soil fertility and so on. For three types of seedlings, transplanting seedlings, plots without base fertilizer or seed fertilizer, low-lying, moist plots and interplanting corn, it is necessary to recover seedling fertilizer as early as possible, generally before and after seedling setting, and plots with strong seedlings, high soil fertility and sufficient base fertilizer can not be applied or less. In addition to the application of chemical fertilizer, mature organic fertilizer can be applied. The amount of topdressing at seedling stage, in principle, phosphate fertilizer and potash fertilizer are all applied with base fertilizer, and the amount of nitrogen fertilizer topdressing should be determined according to soil and seedling conditions. In general, 20-30% of the total nitrogen is applied in high-yield fields, 50-60% in middle-yield fields, and more than 60% in low-yield fields. Topdressing method: generally use ditch application or hole application. If the depth is more than 5cm, leave the seedling more than 10cm, do not burn the seedling.