Department of Plant, Soil and Microbial Sciences Weeds

Horsenettle (Solanum carolinense L.)

Life Cycle:

Perennial. Flowers bloom in late-spring to early summer, forming yellow berries containing seeds that shrivel in the fall. The aboveground plant tissue dies back after a frost.

Emergence:

Seeds germinate well within 1-inch of the soil surface. Very few plants emerge from seeds at depths of 4-inches or greater. Two-thirds of roots (6-inches long) buried 18-inches below the soil surface can produce new shoots; emergence decreases at greater depths.�

Reproduction:

Mode(s) of Reproduction: Reproduces by seed and vegetative reproduction of new shoots from creeping roots.

Dispersal Mechanisms: The berries, with seeds inside, are eaten by animals and then deposited. Berries that are not eaten drop to the ground.

Longevity: Under laboratory conditions seeds remain viable for at least 7 years.

Dormancy: Some of the seeds of horsenettle are dormant at the time of dispersal in the fall. This dormancy is broken by the following spring. 

Competitiveness:

Horsenettle established for one year prior to planting snapbeans reduced yields by 18 to 20%. As the length of establishment increased so did yield reduction, with yields reductions of 48 to 65% in snapbeans competing with three year old horsenettle plants. Horsenettle has also been shown to reduce yields in peanut by up to 40%. In addition to being a good competitor with crops, horsenettle is poisonous to livestock.

Preferred Soil/Field Conditions:

Can grow in a variety of soil types, though it prefers a sandy or gravelly textured substrate.

Management:

Biological 

Predation/grazing: No information.

Decay: No information.

Mechanical

Tillage: Tillage at any depth can increase the spread of horsenettle.

Rotary Hoeing: Not effective.

Flaming: Not effective.

Mowing: Mowing early in the season encourages horsenettle growth; mowing later in the season decreases growth.

Cultural

Crop rotation: No information.

Planting date: Most likely will not affect horsenettle infestations.

Chemical

Application timing and effectiveness: Very few herbicides are effective at controlling horsenettle. Sequential herbicide applications are necessary for control.