Why Does Corn Tassel Early?

Temperature

• Corn grows best when the daytime temperatures range between 77 and 91 degrees F and the nighttime temperature ranges between 62 and 74 degrees F. Growth slows when daytime temperatures rise above 95. Although stress due to high temperatures reduces the amount of corn produced, plants can tolerate temperatures less than 100 degrees without suffering too much damage, as long as they're given enough water. Lack of water, combined with high temperatures during tasseling and silking, can reduce yield by 5 to 10 percent every day.

Moisture

• Providing corn with enough moisture is complicated by the fact that humidity, air temperature, wind and solar radiation affect how much water is needed. Plants need more water on hot, sunny days when there's a lot of wind and the humidity is low, and they need less water when it's cloudy and cool. Stress caused by a lack of water before tasseling can result in 10 to 40 percent less corn being produced. Provide corn with an inch of water every 7 to 10 days until it reaches a height of 15 inches. Increase water to an inch every five to seven days until the tassels appear, then provide 1 inch every three days until the corn is mature. Lack of water can also lead to nutrient stress because the corn can't absorb nutrients from dry soil.

Fertilizer

• Test soil in the fall to determine fertilizer requirements. Fertilizing corn without a soil test could result in providing too much or too few nutrients. Corn should be grown in soil with a pH between 5.6 and 6.2. Acidic soil, with a pH below 5.2, may result in phosphorus becoming unavailable to plants. A low pH can be corrected by adding lime to the soil. Nitrogen is necessary to produce corn with long, green flag leaves and dark green husks. A lack of phosphorus can cause stunting and purple leaves. Other nutrients required include sulfur, manganese, boron and zinc. Corn that's grown early, in cooler temperatures, can benefit from starter fertilizer, which contains small amounts of nitrogen, phosphorus and sulfur, along with various micronutrients.

Nematodes

• Nematodes are microscopic roundworms that damage corn by feeding on the roots. The damage they cause results in fewer roots that are able to absorb water and nutrients, which leads to stress that causes the corn to mature earlier. Above-ground symptoms of nematode damage include stunted plants, yellow leaves and uneven tasseling. Nematicides can be applied to the soil to help control these pests. Nematode-resistant corn varieties are also available.