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Prep Early to Protect Lettuce from Costly Diseases

June 27, 2019
this agronomic image shows a field of lettuce.

If you grow lettuce, you know the crop faces many difficult-to-control diseases throughout the season. Sclerotinia, one of the most common and destructive diseases in lettuce, should be top of mind given the wet season we’ve had, because it thrives in moist conditions.

Two closely related pathogens, Sclerotinia minor and Sclerotinia sclerotiorum, cause lettuce drop, which takes a serious toll on your crop’s marketability and yield potential. As you look ahead to planting lettuce later this year, be sure to prepare with a robust scouting plan and a fungicide that offers improved, powerful protection against harmful diseases.

What should you look for?

University of Missouri reports that Sclerotinia first infects the outer leaves and crown tissue. Next, it wilts foliage until the entire plant is affected. Dark, pebble-like fungal structures may be visible on infected tissue and survive in the soil for years.

When left untreated, Sclerotinia sclerotiorum develops airborne spores that spread lettuce drop and cause widespread damage across neighboring fields. According to the University of Arizona’s Yuma Center of Excellence for Desert Agriculture, Sclerotinia sclerotiorum-caused yield loss can range from 1% to nearly 75%, and total crop loss may occur with lasting ideal conditions for disease development.

This agronomic image shows leafy veg rot

Applying a powerful, novel fungicide can help you fight diseases like lettuce drop that compromise marketability and yield potential. Registered for use on lettuce, Miravis® Prime fungicide offers better management of several difficult-to-control diseases, including both forms of Sclerotinia.

A 2018-2019 trial by University of Arizona researchers shows that Miravis Prime is the top-performing treatment for both forms of Sclerotinia. In replicated plots with lettuce drop pressure, plots treated with Miravis Prime saw fewer diseased plants than those treated with competitor fungicide brands.

Miravis Prime-treated plots with Sclerotinia sclerotiorum presence see fewer diseased plants on average.[1]

This agronomic image shows the effectiveness of different treatments.


With fludioxonil (FRAC group 12) and Adepidyn® fungicide (FRAC group 7), Miravis Prime provides improved power and stamina to control a broader spectrum of diseases. In addition to managing Sclerotinia, Miravis Prime sets a new standard for control of gray mold, powdery mildew and more.

As you plan ahead to planting your crop, prepare for damaging diseases and maximize quality and marketability by adding a powerful fungicide with next-level chemistry to your management plan.

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Product performance assumes disease presence.

Performance assessments are based upon results or analysis of public information, field observations and/or Syngenta evaluations.

©2019 Syngenta. The trademarks or service marks displayed or otherwise used herein are the property of a Syngenta Group Company. All other trademarks are the property of their respective owners.

[1] Seeding and wet dates: Nov. 15, 2018.

Variety: Magosa

Thinning date: Jan. 3, 2019. Fungicide was first applied after thinning.

Disease assessed at crop maturity on 20 and 22 Mar for S. minor and S. sclerotiorum, respectively.