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Weed Control in Carrot1

Peter J. Dittmar and Ramdas Kanissery 2

Although carrots may be grown on mineral soils, production in Florida is almost exclusively on the organic soils of central and south Florida. While the practice of seeding the crop in six lines per bed enhances total yield that may be harvested per acre, it also mostly prevents the use of mechanical cultivation for weed control.

Control of weeds is extremely important in several aspects. Because weeds directly compete with carrots for nutrients, space, and water, they reduce the size of carrot roots and thus reduce overall yield. Weeds also cause carrot roots to be deformed and therefore unmarketable. Weeds that present late in the season may also cause severe harvesting problems.

Weed control is critical early in the season because it will allow the formation of good, straight roots, and it is important for the above reasons throughout the growing season.

Currently, only linuron is labeled for preemergence (both carrots and weeds) application on muck soils, and only linuron, pendimethalin, and trifluralin are labeled for preemergence on mineral soils.

Linuron and metribuzin may be applied over the top of carrots to control small broadleaf weeds. Great care should be taken to apply these herbicides at the correct rate and at the correct growth stage of the crop and weeds (see Table 2). Carefully read the labels for directions.

Fusilade® DX, Poast®, and Select® are labeled for the control of emerged grass weeds. These may be applied several times during the growing season, up until 45 days before harvest for Fusilade® and 30 days before harvest for Poast® and Select®.

Included in the tables is the mode of action (MOA) code. These numbered codes assist growers with rotating herbicide modes of action to reduce the risk of developing herbicide resistance.

Read and follow all label directions for each herbicide used.


Table 1. 

Chemical weed control before carrot emergence

Table 2. 

Postemergence chemical weed control in carrot


1. This document is HS201, one of a series of the Horticultural Sciences Department, UF/IFAS Extension. Original publication date March 1999. Revised June 2015. Reviewed January 2019. Visit the EDIS website at for the currently supported version of this publication.
2. Peter J. Dittmar, associate professor; and Ramdas Kanissery, assistant professor, Horticultural Sciences Department and Southwest Florida Research and Education Center; UF/IFAS Extension, Gainesville, FL 32611.

The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication do not signify our approval to the exclusion of other products of suitable composition. All chemicals should be used in accordance with directions on the manufacturer's label. Use pesticides safely. Read and follow directions on the manufacturer's label.

Publication #HS201

Date: 1/10/2019



    • Peter Dittmar
    • Ramdas Kanissery