Seed supplies are becoming tight. If you have not booked this year’s seed, please contact your seed representative as quickly as possible to assure your choice of varieties and quantity are available. New producers or those who haven’t raised cotton in several years should do a thorough job of planning their crop strategies prior to planting. As 2017 illustrated, how the crop gets harvested and where it’s going be ginned is critical.
Successful Planting Strategy
Next to variety selection, most likely the next very important decision a producer makes is when to plant. The single most important issue to recognize is that cotton seedlings can be damaged by cool, wet soils. Depending upon the region of the U.S., many producers typically begin planting based the calendar date. However, the long-term optimum planting window for most states is determined based on field trials and average soil temperatures. Although soil temperatures can sometimes be high outside of this window, many times they can drop, especially if precipitation is obtained and a cold front pushes through the region.
The optimum temperature for cotton germination is near 85 degrees F°. Cooler temperatures can lead to poor stands or stand failures if the correct conditions align. Under cool temperatures the physiological processes involved in germination can be very slow which can in turn result in slow growth and perhaps increased susceptibility to various seedling disease pathogens.
It is suggested that planting be delayed until 1) mid-morning temperatures in the rooting zone exceed 60 degrees F° at a 6-inch planting depth, and 68 degrees F° at the 2-inch depth; 2) the five-day forecast indicates dry conditions and at least 25 DD60 heat units; and 3) the five-day forecast projects low temperatures above 50 degrees F°.
The standard calculation for cotton DD60 heat units is:
((maximum air temperature, F° + minimum air temperature, F°) / 2) – 60 = DD60 heat units
Essentially, the average air temperature for the day is determined and the 60 degree F° developmental threshold for cotton is subtracted. The DD60s for each day are then totaled. If one has faith in the local forecast, then the projected high and low for the following several days can be used to calculate DD60s.
Click here to read more in the Oklahoma Cotton Comments.