Field Insights

Cotton Diseases: A Lineup of Suspects

Plan your disease management strategies around target spot and areolate mildew to protect cotton yields.

April 2024 | By Syngenta Thrive

Are you prepared to tackle tough cotton diseases this season? Target spot and areolate mildew can have serious impacts on cotton yield if left unchecked. As you plan your disease management strategy, use this information as a refresher about some of the mid- to late-season problems to keep an eye on:

Target Spot

Damage: Target spot may cause significant defoliation very quickly after infection and has become more common in the U.S. In severe cases, it can cause yield losses of more than 200 lbs. of lint per acre. Rank growth, short rotations, excessive irrigation, higher rainfall and warmer temperatures can lead to disease development.
Symptoms: This disease is usually distinguishable by dime-sized spots with circles inside that make the spot look like a target. Target spot causes plants to lose leaves from the bottom before progressing upward. It is sometimes confused with Alternaria or Stemphylium leaf spot, but is usually seen target spot lower in the canopy.

Areolate Mildew

Damage: Before 2017, this fungal disease was typically only found in southeastern GA but has since spread. In 2018 and 2019, NC cotton fields also experienced damage from areolate mildew.
Symptoms: This late-season disease favors wet and humid weather and causes a characteristic powdery, white-to-gray growth on the underside of leaves. It can cause defoliation and impact yield if it occurs more than four weeks.

Boll Rot & Hardlock

Damage: Severe problems from boll rot and hardlock are an annual concern if you experience cool, wet weather late in the season, such as extended rains from a hurricane or tropical storm. Hardlock caused by Fusarium verticillioides can be devastating in the FL Panhandle.
Symptoms: Boll rots begin deep in the cotton canopy. To a certain extent, rotted bolls as well as bolls with hardlock — where the boll will remain unopened even at maturity — can be observed in low, scattered quantities in almost every cotton field.

Use a Tougher Defense

Properly timed fungicide applications can effectively manage these diseases. Miravis^® Top fungicide is a high-performing solution for cotton growers facing possible yield loss due to disease. Miravis Top delivers tougher disease control in cotton to protect yield and ROI potential.

ARTICLE HIGHLIGHTS

Target spot and areolate mildew can decrease cotton yield potential if left untreated.
Properly timed fungicide applications are key to protecting yields.
Miravis^® Top is a high-performing fungicide that can help growers protect cotton fields.