What is in this article?:
- Cotton seedlings can be damaged by cool, wet soils.
- Dry soils will warm up faster than moist soils.
- Soil temperatures have been quite cool this spring.
Be cautious with cool soils when planting cotton.
The single most important issue to recognize at cotton planting time is that cotton seedlings can be damaged by cool, wet soils.
Soil temperatures have been quite cool this spring. Last year, we planted our first trial on April 24 and had experienced warm soil temperatures and an excellent forecast. Every season is different.
Dry soils will warm up faster than moist soils. Since we continue to have roller coaster air temperatures, when we do get rainfall the soil temperatures will be lower. It is a good idea to have your own soil thermometer to check your own specific field situation and wait for soil temperatures appropriate for cotton planting.
BMPs for cotton planting
Best management practices for cotton planting under normal soil moisture conditions would be to delay planting until:
1) The 3-day Oklahoma Mesonet bare ground average soil temperature at the 4-inch depth is at least 65 degrees. See: http://www.mesonet.org/index.php/weather/soil_temperature and http://www.mesonet.org/index.php/weather/category/soil_moisture_temperature
2) The 5-day forecast calls for dry weather and a minimum of 25 to 50 DD60 heat units. The normal calculation for cotton DD60 heat units is: (maximum air temperature + minimum air temperature) / 2) - 60 = DD60 heat units.
Essentially, the average air temperature for the day is determined and the 60-degree developmental threshold for cotton is subtracted. The DD60s for each day are totaled. If you have faith in your local forecast, the projected high and low for the following several days can be used to calculate DD60s.
3) Low temperatures are forecast to remain above 50 degrees for the 5 days following planting.
If equipment constraints and large acreages require producers to plant during less than optimum conditions, they should realize that seed quality and seeding rate become very important. The seeding rate can be adjusted on the planter. However, with expensive transgenic seed, seed treatments and technology fees, increasing seeding rate is not a palatable option for most producers. Therefore, seed quality becomes very important.