A Detailed Explanation of Corn Seedling Raising Methods and Key Technical Points

SummarySeedbed seedling raising: spread nutrient soil into a seedbed surface, then scatter the seeds on the seedbed surface and cover with soil; when transplanting, lift the seedlings together with the soil. Nutrient cup seedling raising: use cup-shaped containers or a pot-making machine to make the nutrient soil used for raising seedlings into nutrient cups, then sow and raise seedlings in the nutrient cups; after the seedlings are grown, transplant them together with the cups. Soilless seedling raising: use wooden boards or other containers to make seedling trays, and raise seedlings in the trays by hydroponics.

1. Methods of raising corn seedlings

1. Seedbed seedling raising

(1) First spread nutrient soil suitable for raising seedlings into a seedbed surface, then evenly scatter the seeds on the seedbed surface and cover with soil; when transplanting, lift the seedlings together with the soil.

(2) The thickness of the nutrient soil is 6-7cm; during this period it must be compacted and smoothed. This seedling raising method is relatively simple to operate, and the seedbed occupies little space. Generally, a seedbed of about 2 m can provide seedlings for transplanting 1 mu of land, but when lifting the seedlings it is easy to damage their roots and stems.

2. Nutrient cup seedling raising

(1) Cup-shaped containers or a pot-making machine can be used to make the nutrient soil used for raising seedlings into nutrient cups, then sow and raise seedlings in the nutrient cups; after the seedlings are grown, transplant them together with the cups. This seedling raising method can reduce damage to the roots and stems of the seedlings when lifting them, and can also shorten the recovery period after transplanting. The survival rate after transplanting is relatively high, and the yield-increasing effect is good, but making the cups is rather troublesome.

(2) Generally, the nutrient cups can be made into cylindrical or square shapes. The bottom diameter of the cylindrical shape is 5-6cm, and the height is 7-10cm; the square shape is generally 6cm. The number of nutrient cups can be determined according to the planting density.

3. Soilless seedling raising

(1) Soilless seedling raising is also called tray seedling raising or water seedling raising. It uses seedling trays made from wooden boards or other containers, and generally raises seedlings in the trays by hydroponics.

(2) This seedling raising method has relatively low cost and is easy to manage, and it can also prevent early spring frost damage and soil-borne diseases. Generally, about 10,000 seedlings can be raised per sq m, enough to supply 1.5-2 mu of field for planting.

2. Common diseases and pests of corn and their control methods

1. Northern leaf blight and southern leaf blight

(1) Northern leaf blight mainly harms the leaves, and when the disease is severe it can also endanger the husks. In the early stage of the disease, small grayish-green spots appear, and in the later stage they gradually begin to spread, causing the entire leaf to be covered with large irregular lesions, with black mold-like material on the spots.

(2) Southern leaf blight mainly harms the leaves and stems. When the disease occurs, rectangular or oval spots appear. During this period, diluted amisida can be selected for spraying control.

2. Bacterial wilt

(1) Bacterial wilt causes serious harm to corn. The peak period of the disease is at the corn jointing stage, and the disease is not easy to detect. It causes the entire plant to wilt and die. Generally, when the stem is peeled open, the pith inside is found to have turned brown.

(2) Because bacterial wilt is not easy to detect, professional chemicals can be used for root drenching in the early stage of corn planting.

3. Hispa

(1) The shell of the hispa is relatively hard. It often lurks in the leaves and gnaws on them, causing corn leaves to wither and die. When hispa reproduce in large numbers, they can easily cause large areas of corn leaves to wither and die.

(2) During this period, manual control combined with chemical control can be adopted. For chemical control, pollution-free pesticides are suitable for spraying and killing, and then the diseased leaves should be cut off and burned.

4. Stem borers

(1) Stem borers are also called heart borers. They are a common pest of corn, often gnawing on the stems and leaves of corn and destroying the stem and leaf tissues, causing corn to lack nutrients, which is not conducive to its growth. When the damage is severe, the entire plant can wither and die.

(2) During this period, professional insecticides can be used to fill the heart or spray for control.

5. Rust disease

(1) Rust disease mainly harms the leaves. In the early stage of the disease, round lesions appear on the leaves, and there is rust-colored powder. In the later stage, spores appear on the lesions. These spores can safely overwinter and, in the second year, spread again through contact with airflow. The disease gradually expands and causes serious harm to corn.

(2) During this period, hybrid seeds with strong disease resistance can be selected, and fertilization should be reasonable during planting. In the early stage of the disease, wettable powder triadimefon can be diluted and sprayed, and when the disease is severe it should be sprayed repeatedly.