Many in the area are just now in the thick of planting.  For those who have not yet put seed in the ground, please check my post from last week on seeding rate.  For those that were able to capitalize on our April window, you’ve already properly selected seeding rate and now you are looking at possibly a thrips spray or your first post application for weeds.  As normal, your crop looks ‘sickly’, having fought through a blackberry winter, cloudy conditions, and in some areas, additional rains that were not needed.  The second step of moving our cotton budget out of the red and into the black is recognizing inputs which provide a return on investment and those that do not.  Spoiler- most of the products that attempt to hitch a ride in the tank with your early season insect or weed control products often don’t pay for themselves.  In this post, I cover a few of the inputs we have evaluated to help you understand where not to invest.  Special thanks to Dr. Bradley Wilson and Dr. Brian Pieralisi for their contributions to this article.

Foliar fungicides applied for the sake of ‘plant health’; biologicals lacking replicated, scientifically significant results; adjuvants not suggested by the label or recommended by Extension; ‘pop-up’ or starter fertilizers- all of these inputs are often thrown at ‘sickly’ cotton in an attempt to ‘perk it up’.  I’ve tested my share of these over the years, same as Dr. Brian Pieralisi (Cotton Specialist at Mississippi State) and Dr. Bradley Wilson (Cotton Specialist at the University of Missouri).  To date, I have not generated any data to suggest any of these applications are warranted or are capable of even generating enough of a yield increase to cover the cost of the given input.  Many of these products are sold with testimonials instead of replicated data.  Many times, the lack of crop response to the product is masked by improved growing conditions after the application.

Foliar fungicides should be used to target a disease, not a lack of sunlight and cooler-than-desirable temperatures.  I had an opportunity to summarize ten trials completed across the cotton belt evaluating early season applications of foliar fungicides in cotton- for those interested, you can find that paper here. Some foliar fungicide applications between the 2 to 4 leaf stages actually decreased node count.  To wrap up the discussion of early-season fungicides, allow me to quote the concluding remarks from that paper.  “Fungicide treatment did not impact plant height or vigor ratings collected at 14 or 28 DAA, chlorophyll meter readings, lint yield, turnout, or fiber quality parameters in any site-year. Failure of fungicide treatments to positively impact in-season growth measurements, yield, and yield parameters suggests the evaluated fungicides should not be applied early-season for the purpose of improving ‘plant health’ and should instead be reserved to target above-threshold levels of disease incidence/severity” (Raper et al., 2019).

Next, lets briefly discuss biologicals.  Dr. Brian Pieralisi has been leading a beltwide effort to evaluate half a dozen products since 2023 (special thanks to Cotton Inc. for supporting this work).  He has presented his findings from this research several times- including at our Cotton Focus meeting in 2024 and in 2025 (presented by his graduate student, Mr. Will Rutland in 2025).  None of the evaluated biological products have generated significant yield increases.  I visited with Dr. Pieralisi today by phone.  “We have found no yield response when compared to a control,” Dr. Pieralisi reported.  “The only differences we have seen in yield have been associated with nitrogen rate, not the microbial products.”

Starter fertilizers have been regularly considered in corn and more recently in some high yield soybean scenarios.  However, results from cotton are not even mixed in our environment- they simply do not result in an increase in yield.  While we do occasionally see sulfur deficiencies prior to first flower, sulfur applied with your nitrogen application should be sufficient to meet plant demands.  Dr. Bradley Wilson recently started evaluating starter fertilizers in the bootheel of Missouri.  The 2025 season will complete his second year of data.  Dr. Wilson reported, “The trial results in 2024 showed no yield increase from any starter fertilizer evaluated.  The lack of response isn’t surprising, though.  The nutrient demands of cotton are very, very low early in the season.”

While I cannot prove it with data, I must admit it feels like more and more products are being brought to the market every year.  By the time my colleagues and I get data generated on many of these, they disappear and are replaced with another product which also provides no return on investment.  Dr. Pieralisi said it best: “This is not the time to be trying to incorporate new products that are not yet proven.”  Request data from a third party.  If the product is worth purchasing, 9 times out of 10 they will lead with that data.  If they cannot provide, pass.

As always, reach out to your local Extension professional if you have questions concerning a new product.