Corn prices are falling again: ten types of mistakes to avoid in planting management

Recently, corn market prices have been falling continuously. Under such market conditions, growing higher-quality, high-yield corn is the way out. The editor consulted relevant experts and, following the order of corn planting management, compiled 10 types of mistakes that grain farmers make in corn management. See which ones you have made, and do not repeat them when planting next year.

1. Mistakes in sowing:

Viewpoints:

1. Ordinary seeds can be used for single-seed sowing. Many farmers are not impressed by seeds for single-seed sowing, believing that ordinary seeds can simply be winnowed with a basket and the small grains picked out, and then they can be used as single-seed sowing seeds just the same.

2. Setting plant and row spacing arbitrarily, with no concept of density, always thinking that dense is better than sparse. Many machine operators modify seeders into structures that can adjust row spacing at will, sowing at 50 cm row spacing. Plant spacing is set at 17-18 cm.

3. Seed fertilizer not placed in a separate row.

4. Irrigating with flood irrigation to supply the emergence water.

5. Sowing too shallow is unbearable, so the deeper the sowing the better.

Explanation:

Every year farmers suffer losses because of this. In the past many farmers used manual dibbling to sow, and the sowing effect was not as good as it is now. What is the reason for the success of single-seed sowing?

The success of single-seed sowing depends on the following elements, none of which can be missing:

1. High-quality seeds, with high purity, no lower than 98%, and high germination rate and germination vigor, no lower than 95%. Most ordinary corn seeds cannot meet this requirement. Picking them by hand will not work.

2. The greatest success of single-seed sowing is achieving scientific planting density. A variety can only reach its highest yield under reasonable density; whether density is too high or too low, high yield cannot be achieved. Too high density can also cause lodging, empty stalks, disease susceptibility and other problems, causing varying degrees of yield reduction. Too sparse will also reduce yield, but will not cause lodging or empty stalks.

3. Ensuring seedlings after sowing is key. Improper sowing methods will cause missing seedlings and broken rows, thereby affecting density and yield. Fertilizer burning seeds and sealed, rotting seeds are the main factors causing missing seedlings. Only plots without irrigation conditions must be sown deep to reduce the impact of drought on emergence. Plots that can be watered at any time must be sown shallow, with sowing depth not exceeding 5 cm, and 3 cm being best. Sowing too deep and then flooding with irrigation will cause the seeds to suffocate and rot because they cannot breathe. Applying seeds and fertilizer in the same row will cause fertilizer to burn the seeds, and the problem is more serious when a large amount of fertilizer is used.

2. Mistakes in herbicide use:

Viewpoints:

1. Not knowing the categories and application periods of corn herbicides, and spraying and using them indiscriminately.

2. Mixing herbicides with organophosphorus pesticides and micronutrient fertilizers to save labor.

3. Not following the labeled dosage, and arbitrarily increasing the amount of pesticide.

4. Buying obsolete types of herbicides just because they are cheap.

5. Using motorized sprayers for application just to be quick.

6. Spraying a bit more when there is pesticide left over.

Explanation:

Every year farmers cause corn yield reductions because of herbicides. The fundamental reason is that farmers do not understand herbicides and have not mastered relevant knowledge. Corn weed control can be divided into three periods. The types of herbicides used in each period are different and must not be used indiscriminately.

Pre-emergence weed control, commonly known as soil-sealing herbicide, includes alachlor, acetochlor, butachlor, atrazine-acetochlor mixture, and atrazine.

Plots using pre-emergence weed control should pay attention to the following aspects:

First, soil moisture should be relatively high. After corn sowing, apply after rain or after irrigation. If the soil is dry or small weeds have already emerged, it basically cannot be used.

Second, when wheat stubble is relatively high and field wheat straw covers the ground, it is best not to use this type of herbicide, because it cannot be sprayed onto the ground to form a herbicide layer, and therefore cannot kill weeds germinating from the soil surface.

Third, soil-sealing herbicides are applied earliest; once the effective period passes, weeds will quickly grow, requiring a second supplementary spray of other herbicides, wasting manpower and materials.

Fourth, soil-sealing herbicides easily make corn leaves yellow, especially when applied at high temperatures, and can easily damage roots. In view of the above problems, pre-emergence weed control is now gradually being replaced by post-emergence weed control.

From 2 leaves after emergence to before 5 leaves, the main goal is to eliminate small weeds. The herbicides used at this time are generally based on rimsulfuron and nicosulfuron, and compound formulations mainly add atrazine, such as Dajie and others. Generally about 7 days after application the weeds turn yellow, and about 20 days later the weeds wither and die. During the 2-5 leaf stage after corn emergence, whole-field spraying can be used, with good weed control effect and high safety.

There are also individual varieties sensitive to this type of herbicide; the plants will have yellow leaves, but they can recover in about 1 month without affecting yield. Sweet corn, seed production fields, waxy corn, and some Denghai varieties are prone to phytotoxicity and should be used with caution.

Special reminder:

Corn fields using whole-field spraying should be treated within 5 leaves. After more than 5 visible leaves, do not spray, and do not use organophosphorus pesticides within 7 days before and after application; otherwise, directed spraying should be used. In North China, if nicosulfuron is applied at more than 3 grams of active ingredient per mu, phytotoxicity is likely to occur.

When using this type of herbicide, encountering high temperatures, large dosage, repeated spraying, late application timing, or spray liquid entering the corn whorl may all cause phytotoxicity. The 6 to 9 leaf stage is the period when corn is most sensitive to herbicides; application at this stage will bring phytotoxicity. After 9 leaves, low-dose directed spraying between rows can be considered to control weeds.

Note:

Post-emergence herbicides with the two components 2,4-D butyl ester and MCPA-sodium should not be used, as they very easily cause phytotoxicity! Symptoms of corn phytotoxicity are corn leaves becoming narrow or shrunken, the heart leaf rolling into a straight stick shape, or the heart leaf being difficult to emerge and appearing like a cow's tail. Stems twist, root crowns become brittle and easily break or lodge, stem bases thicken into a goose-head shape, and may even split. In severe cases, upper plant development and growth are blocked, upper leaves are deformed, tassels develop incompletely, and ears are deformed.

In the middle and late stages of corn growth, when weed overgrowth occurs, paraquat can be selected, using a 20% concentration at 150 times dilution, with a protective shield for directed spraying. Because this is a fast-acting, non-selective herbicide mainly with contact action, even if the spray liquid “splashes” onto corn leaves, it only causes local drying and will not cause “plant death.”

At this stage, absolutely do not use glyphosate-type products. This is a non-selective systemic herbicide, mainly aimed at perennial weeds, mostly used in orchards, ditches, and roadside weed control, and can also be used after crop sowing and before emergence. If this pesticide is used in the middle and late stages of corn, because it has systemic action, even slight carelessness will cause lower leaves to be damaged and then transmit throughout the whole plant, leading to corn plant death and serious yield reduction.

3. Mistakes in fertilizer use:

1. Mistakes in urea use. Do not apply urea in these ways: do not mix it with ammonium bicarbonate, as it will slow urea conversion and thereby cause volatilization and leaching losses; do not broadcast it on the soil surface, as most nitrogen is volatilized during the conversion of urea to ammonia, with utilization rate only 30%; do not use it as seed fertilizer, because the small amount of biuret contained in urea will poison seeds and seedlings, affecting seed germination and seedling growth; do not water immediately after applying urea, because urea conversion takes 2-10 days to complete, and immediate watering will cause urea to dissolve in water and be lost with the water.

Pay attention to the use of corn grain-filling fertilizer. After corn tasseling, in many cases the soil nutrients can no longer meet the needs of later growth and development. To obtain high quality and high yield, some quick-acting nitrogen fertilizer must be applied as appropriate to prevent premature aging of corn, promote corn filling and full grains, and increase thousand-grain weight.

2. Excessive fertilization, believing that more fertilizer means more grain. Too much fertilization will cause fertilizer residues and soil compaction. Increasing organic fertilizer and farmyard manure, and appropriately spraying zinc fertilizer and other foliar fertilizers, has an obvious yield-increasing effect on corn.

3. Timing of controlled-release fertilizer use. Controlled-release fertilizer (slow-release fertilizer) has components that control the release time of nitrogen fertilizer in the fertilizer. The nitrogen it contains will be slowly released according to different corn growth stages, so it has the characteristic of one application being effective for one season. Qualified controlled-release fertilizer can ensure that corn does not run out of fertilizer in the later growth stage. The best time to use controlled-release fertilizer is 20 days after corn emergence. Apply it in furrows.