Speaking on behalf of the Mid-South Cotton Specialists Working group at the 2018 Southern Cotton Ginners Annual Meeting, Darrin Dodds, associate Extension research professor, cotton agronomics, Mississippi State University, told the crowd, “When I started this position in 2007, cotton had dropped from 1.2 million acres to 660,000 acres in one fell swoop. Had you told me then where we would be today from a yield standpoint, I wouldn’t have believed you.”
YIELDS AND PESTS
Dodds’ presentation included an historical review of yields for all five Mid-South states from 1866 until today. When highlighting the last six years compared to the six years prior, every state except Tennessee, averaged over 1,000 pounds — but Tennessee’s average yields have increased 160 pounds in the last six years. “Three of last six years in Mississippi, our state’s average yields were over 1,200 pounds. I didn’t think that gain was attainable 10 years ago.”
A yield increase can also be seen in Arkansas cotton; 887 pounds six years prior, compared to 1,119 pounds the last six, and in Louisiana, 829 pounds six years prior, compared to 1,009 pounds the last six years. “Missouri has been knocking on the 1,000-pound average door the previous six years, and they averaged 1,073 this past season,” said Dodds.
Those numbers paint a clear picture of what is driving cotton’s momentum in the Mid-South — yield. While yields are increasing, another reason cotton’s momentum continues are the big harvests across the Mid-South states. “Unfortunately, those crops have come at a big expense,” adds Dodds.
Many farmers had to make multiple control applications for worms. Those applications are not cheap and those costs dug deep into the pockets of producers. Every meeting where Dodds spoke this past season, he stressed that growers should spend their money wisely. The days of trying something on a number of acres and not knowing the potential ROI should be over.
“This is especially true considering what an on-board module harvester costs, what a bag of seeds with traits costs, or what land costs,” says Dodds. “The level of technology investment is forcing growers to maximize their ROI. It’s nice to have new toys, but if they don’t return a value, what good are they?”
Dodds took a stern tone when he brought up dicamba, warning that if the number of complaints called in last year occurs again this growing season, the chemistry could be taken away or allotted to growers on a limited basis moving beyond 2018.
“Things like this put farming in the national spotlight, and that type of negative publicity can hurt agriculture in more ways than just not being able to use a product.”
A two-year preliminary registration for the chemistry label is currently up for debate. Dodds asked everyone in the room to keep in mind that they might not lose the varieties but the chemistry could be pulled and, therefore, any application made in the absence of a federal label would be a federal violation. “The dicamba issue in cotton, and especially in soybeans, should be concerning to everyone,” adds Dodds.
Growers continue to rely on glufosinate (Liberty) to help keep their fields clean. However, continued heavy use could result in resistance and that would put growers in a deep hole with no way out if dicamba is not available, especially on operations with high Palmer amaranth populations.
Of the 52 varieties Dodds included in his Official Variety Trials (OVT) last year, 31 to 64 percent of leaves exhibited symptoms of target spot. This foliar disease was not even on the radar just three years ago. “I was speaking at a meeting on July 3 last year and it started raining. It rained for over two weeks, and we started seeing spots on cotton’s leaves — and then the leaves starting falling off,” remembers Dodds. “Panic really set in when those plants started shedding first fruit position bolls.”
Dodds oversaw a target spot trial conducted by Extension specialists throughout the Mid-South. His slides illustrated the severity levels of the disease from August to September when plants went from 20 percent defoliation to almost 60 percent. “Think about what two shots of fungicides will cost a grower, and it didn’t really slow it down,” says Dodds. “How many $15, $20, or $40 fungicide applications does it take to go from profitable to not profitable?”
In Louisiana, Dan Fromme did report seeing a benefit from two applications of fungicide put out before symptoms materialized on leaves. “I just don’t know how many growers will be willing to fund two applications not knowing if target spot will show up — because sometimes it won’t.”
According to Dodd’s research, just because target spot causes leaves to drop, that does not correlate into lower yields. He had eight varieties that lost less than 25 percent of their bottom leaves, but only three of the varieties were top yielders. “Pay attention to when the disease appears. If it’s in the early part of August, those leaves are just helping you defoliate,” says Dodds.
“I was really surprised we didn’t have target spot move across our acreage in 2017, but we did have some confirmed cases of Bacterial Blight,” said Tyson Raper, assistant professor, cotton and small grains, University of Tennessee.
Target spot and bacterial blight are easy to differentiate. Bacterial blight shows up as water-soaked angular specks across the leaf surface. “These dead regions often run through veins,” says Raper. “Target spot appears as larger lesions on the leaf with concentric rings.”
The panel also touched on the increasing problem of growers having to spray two-gene Bt cotton to control worms. There has been a definite shift in thought processes and recommendations if a grower is planting two-gene cotton. “If you are planting a two-gene Bt cotton in 2018, our entomologist suggests moving to a 20 percent egg threshold, and if you exceed that, you need to make an application,” says Dodds.
“I see growers shifting to three-gene varieties quickly to avoid having to spend extra money on control. However, just because you have three-gene Bt cotton, don’t think you will never have to spray for worms.”
More concerning to Dodds is the reason growers are seeing worms surviving in two-gene Bt cotton — resistance. “Assays have been conducted at Texas A&M on Bt proteins and unfortunately, they are reporting high levels of resistance to a number of those proteins commonly found in WideStrike, Bollgard II and TwinLink cotton,” says Dodds.