Field Bindweed Control in Grain Sorghum

Post on September 18, 2026

Field Bindweed Control in Grain Sorghum

Brent Bean, Sorghum Checkoff Director of Agronomy

Although all crops have generally struggled this year from heat and moisture stress, it seems like most of our weeds have not, especially field bindweed, which has long been one of our most persistent and troublesome weeds. The weed spreads by seed, lateral roots and rhizomes and can infest new fields by seed contamination from combines, other farming equipment and cattle manure. The seed is extremely hard, impervious to water, and can remain dormant and viable in the soil for more than 30 years. It actually is not too difficult to control as a seedling; the problem is that it can begin producing rhizomes and become perennial in as little as six weeks!

Its extensive root system allows it to flourish under drought conditions. Roots of mature plants are fleshy, full of stored energy, profusely branched and penetrate the soil to 6 feet or more. Bindweed starts in small spots in a field, causing only minor crop loss. However, a single plant may spread up to 10 feet in diameter the first year. If left unchecked, over several years the bindweed can occupy large areas, creating a problem requiring a major commitment of time and resources to get it under control. The most common products used to control bindweed are quinclorac, dicamba (Clarity, others), 2,4-D and picloram (Tordon 22K). Quinclorac is sold in at least three formulations: Quinstar 75% DF, Quinstar 4L and Facet 1.5L. The rate of product used will depend on the formulation. Burndown products such as Paraquat and bromoxynil only provide temporary control of bindweed and have little lasting effect. Glyphosate can be effective, but only at very high rates and, even then, control is better when 2,4-D or dicamba is added to the mix.

The most effective time to apply herbicide for bindweed control is in the fall-ideally three weeks before the first hard freeze. Effective fall treatments are 1-2 qt Clarity (dicamba), 0.5-1 pt Tordon 22K (picloram) + 1-2 pt 2,4-D LV4, or quinclorac (22-32 oz Facet 1.5L, 0.75-1.5 pt Quinstar 4L, 5.3-8 oz Quinstar 75DF).

During the sorghum growing season, dicamba, 2,4-D Amine 4L and quinclorac can all be effective in controlling bindweed. To avoid crop injury, follow label precautions on size of the sorghum when applying these herbicides. In general, these herbicides should be applied prior to the sorghum reaching a height of 8 inches. Suggested rates are 6 -8 oz dicamba, 16 oz 2,4-D Amine 4L and the lower rates stated above for quinclorac. A combination of quinclorac and 4 oz of dicamba or 8 oz of 2,4-D can also be used.

My recommendation is to use dicamba or 2,4-D for bindweed control in grain sorghum and to use quinclorac in the fall during fallow. Time and patience are needed when using quinclorac as it may take up to four weeks for the bindweed to die following application. Methylated seed oil is the suggested adjuvant to be used with quinclorac, plus the addition of ammonium sulfate under stressed conditions.

With all of the treatments mentioned, better control will be achieved on non-stressed bindweed that is actively growing. Ideally, bindweed should be treated when runners are approximately 6 inches in length. This gives enough leaf area to intercept an appropriate amount of herbicide to be effective. It is important to note that quinclorac, dicamba, 2,4-D and picloram are all auxin type herbicides and can cause injury if allowed to drift onto broadleaf crops.

The key for lasting control of field bindweed is patience and persistence. Treat bindweed in the fall and regrowth in the spring and summer. The goal should be to never let bindweed have a chance to resupply its root system with carbohydrates. Treat new bindweed plants as soon as runners are 6 -10 inches in length. Even burndown products can be effective if applied diligently. Research has shown that bindweed infestations can be greatly diminished in two to three years if an intense management strategy is implemented.