Texas A&M AgriLife Extension agronomists talk about this year’s RACE trials.
• By Kay Ledbetter •
Much like producers’ fields across the High Plains, the Texas A&M AgriLife Extension Service cotton trials are seeing a significant difference in performance this year between dryland and irrigated trials.
“While cotton can tolerate hot and dry conditions better than many crops, this year’s drought is taking a toll on dryland fields,” says Dr. Jourdan Bell, AgriLife Extension agronomist in Amarillo.
The 2018 Texas A&M AgriLife Randomized Agronomic Cotton Evaluation, or RACE, trials are conducted annually to provide regional producers a comparison of top-selling cotton varieties under different production environments.
Dr. Emi Kimura, AgriLife Extension agronomist in Vernon, says the Rolling Plains is seeing a wide range of conditions, which make these trials very valuable, as no single variety excels in all locations.
Kimura says June was very dry across the Rolling Plains when most of the dryland producers planted cotton, so she expects to see a difference in the varieties on drought tolerance.
Importance Of Variety Stability
“Region-specific variety trials are very important for producers’ on-farm variety selection,” Bell says. “When producers select a cotton variety, it is important that they consider the variety’s stability.
“Stable varieties perform well over multiple years and under different management practices, especially under this year’s harsh dryland conditions. Because precipitation is extremely variable from year to year across the Texas High Plains, it is important to choose varieties with good early season vigor.”
Bell says although this is important for irrigated and dryland systems, producers are “very interested in varieties that perform well on the expanding dryland cotton acres in this region.”
This year’s Texas Northern High Plains and Rolling Plains RACE trials were planted with regional cooperators on dryland and irrigated farms. At each location, eight of the top cotton varieties in the region are being compared in large-replicated plots.
Individual plot sizes are no less than 0.4 acres, so data is representative of farm-scale variety performance, Bell says.
Trial locations are also selected to represent the diversity of conditions across the region. Irrigated trials in the Panhandle region are in Deaf Smith, Hutchinson, Ochiltree, Parmer, Sherman and Swisher counties. Dryland trials are in Gray, Hutchinson and Randall counties. One limited irrigation trial is located in Moore County.
Irrigated varieties include NexGen 3406B2XF, NexGen 3517B2XF, NexGen 3780B2XF, FiberMax 1320GL, FiberMax 1888GL, Stoneville 4747GLB2, DeltaPine 1612B2XF and DeltaPine 1820B3XF. The dryland variety set adds NexGen 3500XF and DeltaPine 1522B2XF instead of NexGen 3517 and DeltaPine 1820.
In the Rolling Plains, there initially were 15 locations — nine dryland and six irrigated — but several sites were lost due to dry conditions, Kimura says.
The varieties planted on irrigated sites were NexGen 4689B2XF, NexGen 4777B2XF, FiberMax 2498GLT, Stoneville 5122GLT, DeltaPine 1522B2XF and DeltaPine 1646B2XF, Phytogen 480W3FE and Phytogen 440W3FE. Under dryland, NexGen 4545B2XF, DeltaPine 1549B2XF, FiberMax 2574GLT and Stoneville 5517GLTP replaced some of the irrigated entries.
“The persistent drought across much of the northern Texas High Plains has significantly impacted dryland producers,” Bell says. “On many fields, cotton is simply surviving. But tillage management is proving to be critical to dryland cotton stand establishment this year.”
She says some dryland producers across the region achieved good stands under limited tillage or no-till fields in rotation with grain sorghum or wheat residue and have been able to take advantage of the small amount of stored moisture. However, under clean tillage, cotton seedlings burned up in early June.
While producers generally replant after a failed cotton crop, there has not even been sufficient moisture for replanting under dryland conditions, Bell says.
Many of the irrigated cotton fields are in a corn-cotton rotation. Just like on dryland, the corn residue was beneficial for stand establishment and enhancing irrigation efficiency. In addition to protecting young cotton seedlings from wind injury, the residue serves as a blanket, minimizing evaporative losses from the soil surface.
“We have seen the same thing in our variety trials,” Bell says. “Fortunately, there was rain in early June that was of great benefit to the dryland trial in Hutchinson County. But across the region, rainfall was too late for many of the dryland cotton fields.”
By mid-July, she says, cotton is typically squaring in the northern Texas Panhandle, just slightly behind the Southern High Plains, where cotton is typically flowering. However, producers in this region plant early maturing or early mid-maturing varieties so they still gain sufficient heat units to finish out the crop.
“Occasionally, we have a wet, cool fall like 2017 that impacts quality. But when we look at long-term weather patterns, we are normally warm and dry when cotton is maturing,” Bell says. “Our irrigated trials, as well as irrigated cotton across the region, are progressing very nicely.”
Kimura says the Rolling Plains has received moisture recently. Although it was “not as much as we wanted, it will still help many cotton producers, especially those growing dryland cotton.”
The maturity stage of cotton in the Rolling Plains varies widely depending on the planting timing and whether the fields are irrigated, she says. However, most of the dryland cotton is still at the squaring stage with very few flowering.
Fleahoppers have shown up in some of the cotton fields, Kimura says, so producers are being encouraged to scout the fields often for insect issues. Fleahoppers can damage the squares and future lint yield and quality.
Kay Ledbetter is an associate editor/communication specialist for TexasAgriLife Research and Texas AgriLife Extension Service in Amarillo and Vernon.