Cotton after wheat is an excellent way to rotate, but it is really important this is done as quickly as possible, according to Dr. J.C. Banks, Oklahoma State University Extension state cotton specialist.
"Planting in wheat stubble is no problem with most modern cotton planters, but we need to plant in moisture instead of dry planting. Wheat at this time of year no longer uses much moisture, so any rainfall received will probably be adequate for planting cotton. One very important thing to consider will be herbicides that may have been used on the wheat. Some herbicides such as Ally, Finesse, Glean and Maverick have a year or longer restriction for rotation to cotton. Express has a 45-day restriction. It is best to look at labels of applied herbicides and determine if there will be any problems with carryover.
"Obviously, the earlier the cotton is planted, the better, but we can plant into mid June and still get a reasonable yield potential. Overall, the best planting window is from May 10-20 for maximum yield potential, but the later planting will normally provide an adequate yield. Varieties should be a short season semi-determinate type, but most varieties we normally plant will fall into this category.
"If at all possible, for wheat harvest use a combine that has a straw chopper/spreader. Although it is possible to plant through a combine windrow, it is better if you have windrows to plant across the heavy straw area instead of the same direction as the combine ran. Heavy straw will build up in front of the planter if you plant in the same direction as the windrow. Straw height can vary, but if the straw is too tall, adequate sunlight may not reach the seedlings as easily.
"Weed control will be with Roundup or Roundup Flex cotton varieties. Many times following harvest, there is an explosion of weed growth from established weeds that are suddenly exposed to sunlight. Be sure to control these as soon as possible following harvest and prior to planting. At this time, tank mix combinations of Roundup or Aim or Paraquat products can be used. Dual can be used immediately following planting if you have potential for a severe problem with pigweeds and small-seeded grass weeds.
"Depending on planter type and moisture conditions, you may not have to make any modifications to your planter. Most planters have furrowing disks and dual angled closing wheels. If ground is hard, you may need to add down pressure springs, but usually, just ensuring the parallel bar that hooks the planter unit to the toolbar is running level, or slightly up toward the rear will be enough down pressure.
"If the disk openers will not clear trash, you may need to use spiked trash managers or notched furrowing disks. In most cases, you can furrow out less than an inch deep and move the trash aside. Again, the rubber closing wheels will probably work, but if you are having trouble closing the slot, and if increasing the pressure will not help, you may need to replace one of the wheels with a spiked closing wheel. There is no one set of recommendations for planter setup, but hopefully, these suggestions will give you some alternatives to follow.
"Planting speed is one of the primary considerations for planting into wheat stubble. If the ground is rough, speed will need to be decreased to prevent bouncing the planter units. Plant population should be 30,000 to 40,000 per acre and the planter should be checked and readjusted if conditions change. When planting into stubble, planting can be shallower because the soil will not dry out as rapidly. In most cases, planting depth should be less than one inch, but ensure the seed is in moist soil. Dry planting should be tried only as a last resort. Receiving marginal rainfall after dry planting sometimes cause seeds to sprout but then die due to limited moisture. If possible, planting into good moisture is preferable."
TALKIN' COTTON is produced by NTOK Cotton, a cotton industry partnership which supports and encourages cotton production in North Texas, Oklahoma and Kansas. For more information on the cotton scene, see okiecotton.org and ntokcotton.org. For questions and comments on Talkin' Cotton, contact [email protected].