Managing cotton within the window of a short-season environment

For cotton growers in the Southern Plains, dealing with a short-season environment presents some challenges that take intense management on the part of the producer. Oklahoma State University Cotton Extension Specialist Seth Byrd, spoke recently at the High Plains Journal–sponsored Cotton U event in Amarillo, Texas, about the topic of managing cotton in such a short growth season and the role time plays in cotton development.

“We can define short seasoning in a lot of ways, but I think the most common way is to talk about seasonal heat and accumulation,” Byrd explained. “We don’t have the luxury of a long season here and, for us, time is a key factor.”

DD60s, or heat units above 60 degrees Fahrenheit, are used to estimate the developmental rate of cotton. However, Byrd says two major factors are omitted from DD60s, which are critical to success with cotton, especially in a short-season environment. The two factors are sunlight interception and rainfall.

“A cloudy day that has a 98-degree high is less beneficial to cotton than a sunny 92-degree day.” Byrd said. “We can’t really make projections of growth with DD60s alone because they leave out a few things.”

Byrd says another consideration is where to cap heat units and daily highs.

“We need 50 to 60 heat units to go from planting to emergence and we hope to get that in as short a period of time as possible,” Byrd said. “With the normal amount of heat units we get in this area, there is not a lot of wiggle room and that’s why getting enough sunlight and avoiding water stress are so key.”

Because of the slim margins of heat units available in the Southern Plains, Byrd says producers have to micromanage all the elements they have control over. Some of the components producers can control include: irrigation management, fertility, variety selection, variety placement, pests and fiber quality. As for environmental aspects, which are out of the grower’s control, they include temperature, sunlight and rain.

“We need to avoid all kinds of stress, including fruit retention,” Byrd explained. “If we drop early squares or flower buds to some sort of stress, whether it’s insects, pests, water or heat stress, that keeps resetting this clock and we can’t afford to do that too many times and still come out with enough harvested bolls to make a profit.”

Along with a short season, weather issues that can play a challenging role in cotton production in the southern Plains. Byrd says early frosts can hinder cotton growth in this environment, but that cool springs can also cause slow emergence and plant establishment.

“Really what I think about, though, is the middle part,” Byrd said. “With the beginning and the end of the season, we can’t do a lot about. To me, what makes it a short season is the time we have for what I refer to as effective blooming, which is the time our crop has to go from white flower to open boll with the heat units it needs to get to a harvestable boll. We can flower way past the bloom date and not get anything out it. It’s staying in that timeline that is the key to success in a short-season environment.”

Lacey Newlin can be reached at 580-748-1892 or [email protected].