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Smart early season corn management

There’s nothing like the anticipation before spring planting. Hybrids have been selected and purchased. Carefully laid crop plans map out what seed to plant on each acre.

The fresh, black dirt is ripe for planting. Equipment is tuned up and ready to roll. A new growing season is about to begin.

This season, tight margins are dialing up the pressure for growers to maximize yield potential and crop quality. That starts at planting and early emergence, when the seed’s potential is greatest. Smart early season management will set up the seed for success, which can pay dividends at harvest.

Practice patience at planting

Planting should be determined by more than just a date on the calendar. Growers are often anxious to get seed in the ground, but early planting comes with risks that could limit yield potential.

Several factors come into play. Monitor the weather forecast and measure soil temperature to determine the best time to plant to avoid seedling injury. If cold rain is predicted in the short-term forecast, it’s best to hold off planting.

Ideally, weather should be dry for a week to 10 days following planting. For greatest seed viability, the soil temperature should be 50°F or warmer at the depth of planting. This allows corn to begin germination. Measure soil temperature at planting depth, rather than the surface, for the best indicator of soil conditions.

Imbibitional chilling can injure the corn plant if the soil temperature drops below 50°F during the first 24 to 36 hours after planting. The seeds absorb, or “imbibe,” water to begin germination.

If the water is too cold, seeds become swollen and less elastic, and they may rupture. Rupturing damages the growth point, causing irregularly grown roots or shoots. If a cold snap hits soon after the seed is in the ground, scout early and decide if damage warrants replanting.

Optimum planting conditions aren’t always achievable. You may need to modify your crop plan to adjust for field conditions. Understand the basic background of each hybrid in your shed. You may need to utilize a more versatile hybrid to maximize yield potential in poor planting conditions.

Watch for germination and emergence patterns

The first few weeks in the ground are critical to the corn plant’s success. Monitor germination and emergence for patterns and signs of stress. Ideally, corn will come up at a nice, even pace. Anything below a 90 percent stand establishment calls for further investigation. Dig in the soil to find the cause and look for these signs:

  1. Improper water absorption: Seeds need to absorb about 30 percent of their weight in water before the radicle and coleoptile can begin to grow. If the seed is sitting in dry or cloddy soils, this process will happen very slowly or not at all.Injury from anhydrous ammonia or excessive fertilizer or pesticide application also can prevent the seed from taking in water. Cool, saturated soil often results in seed rot. Seeds that are brown in color and are soft or fall apart easily likely have been subjected to rot and will die.
  2. Uneven emergence: This can be caused by uneven soil moisture, temperature variability, poor seed-to-soil contact, prolonged water logging or soil insects. Shallow planting may have caused seeds to swell but not germinate.Seeds showing no signs of swelling or germination are typically the result of poor seed-to-soil contact or soil moisture. Cool soil temperatures also can slow the germination process and can predispose seedlings to fungal infection.
  3. Injury symptoms: Twisted roots, club roots or purple plants are signs of herbicide or insecticide and herbicide interaction. It usually occurs due to poor application timing, improper application rate, shallow planting depth, carryover from the previous year’s application or leftover residual in the spray tanks, lines and filters.Always read and follow label directions to ensure you are using crop protection products in the right amount, under the right environmental conditions and at the right stage of crop growth. While there’s no remedy for crop protection-product injury, corn crops can recover and still perform well.

Scout for yield-robbing diseases and pests

Stand establishment depends not only on the success or failure of germination but also on early season stresses. The earlier you scout for issues, the more opportunity you have to minimize impact. If you notice early stand problems, carefully examine damaged seedlings to discover clues to the likely causes.

Most seed treatments protect crops against early season diseases and pests for two to three weeks post-emergence. After that, it’s a grower’s responsibility to get in the fields and check for potential pests or disease issues.

Different seed treatments offer different levels of disease and pest protection. Understanding what treatment was used will help you know what to look for when scouting.

Planting into cool and wet soils increases the threat of fungal infection. Pythium, Fusarium and Phytophthora are the most common fungal species to keep an eye out for and can greatly impact emergence. These common fungi attack plants and cause damping-off or seedling blight symptoms, especially under wet conditions.

Depending on your trait package, early season pests, such as black cutworm, seedcorn maggots, wireworms and more may be a concern. White grubs feed on roots, causing plants to appear stunted, wilted, discolored or even dead. Cutworms attack virtually anywhere and can cause extensive crop damage.

Often an infested field will have a mixed population of several species of cutworms. Because cutworms vary in their feeding habits, early diagnosis of infestation is essential.

Understand the impact of early stress

Few management decisions are as important as those made during planting. You may not be able to recover yield potential lost at planting and emergence. For severely damaged stands, work with your trusted agronomic adviser to assess the need for replanting.

Keep in mind that the longer the gap before replanting, the lower the yield potential. If you choose to replant, select hybrids with relative maturities appropriate for your area.

Strong genetics and trait packages are vital, and the management of those genetics is equally important. Young plants are vulnerable to pests and environmental conditions. Your trusted agronomic adviser can help you understand yield-limiting pressures common in your area and determine how to minimize impact on crop yield.

Get the growing season off to a good start with patience at planting and diligent early season scouting. A bountiful harvest starts with healthy young plants.

(Source – http://www.progressiveforage.com/forage-production/management/smart-early-season-corn-management)


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