HPIPM:Jimsonweed

Taxonomy

Domain	Eukarya
Kingdom	Plantae
Phylum	Magnoliophyta
Class	Magnoliopsida
Superorder	Asteranae
Order	Solanales
Family	Solanaceae
Genus	Datura

Scientific Name

Datura stramonium

Scientific Name Synonyms

Datura stramonium var. tatula

Common Name

jimsonweed

Jimsonweed (Datura stramonium)

Compiled by Melissa Gravesand Marjolein Schat, Montana State University from the following sources:

http://www.ansci.cornell.edu/plants/jimsonweed/jimsonweed.html

http://www.agriculture.state.pa.us/agriculture/lib/agriculture/plantindustryfiles/noxious_weed/jimson_weed.pdf

http://www.doitnow.org/pages/525.html

http://www.ppws.vt.edu/scott/weed_id/datst.htm

Identification and Life Cycle

Jimsonweed (Datura stramonium) is an annual weed in the potato family (Solanaceae). Other common names for jimsonweed include common thorn apple, devil’s apple, dewtry, mad apple, moon flower, devil’s trumpet, and moonflower. The stout stems are green or purple, hollow, smooth, branching, and have inconspicuous hairs. Stems can grow up to 5 feet tall. Leaves are ovate, green to purplish in color and are coarsely serrated along the edges. The leaves appear wavy, are 3 to 8 inches long, and have an unpleasant odor when bruised. The funnel shaped flowers are while or purple with a 5-pointed corolla up to 4 inches long. Flowers grow on short stalks in the axils of branches. The four-segmented seed pods are prickly and burst open at the tip causing the seeds to scatter. Seeds are black, pitted, and kidney shaped and are poisonous. Jimsonweed has a thick and extensively branched taproot.

Habitats

Jimsonweed can grow under a wide range of conditions, but does best in high nutrient soils. Jimsonweed is often found in pastures, fields, waste areas, cultivated areas, roadsides, and railroad right-of-ways.

Impacts

Jimsonweed competes with desired vegetation for water and nutrients. All parts of the plant are poisonous to humans and animals.

Biology and Ecology

Jimsonweed reproduces primarily from seed, although shoots can grow from cut stems. Germination occurs in late spring and early summer. Seeds require disturbed soil to germinate. Seedlings grow quickly and shade out surrounding vegetation. Flowers appear after the plant reaches the 6-8 leaf stage (from May to September), opening at dusk and closing again the following morning. Flowers are pollinated by hawk moths and bees. Under stress it can flower and set seed at just 4 inches tall. Seeds can be spread long distances in hay, chaff, and as a seed contaminant of summer crops. Plants can produce up to 30,000 seeds that remain viable in the soil for many years.

Management Approaches

As an annual plant with long lived seeds, management should be aimed at controlling jimsonweed before seed set occurs.

Biological Control

The threelined potato beetle Lema trivittata causes severe defoliation of jimsonweed and reduces seed production. The fungus Alternaria crassa has been tested as a potential biocontrol agent. In field studies the fungus gave 90% control of jimsonweed at the 2 to 4 leaf stage.

Mechanical and Cultural Control

Small patches can be hand pulled before flowering. If pulled after flowering plant material should be removed as seeds will ripen within capsules of cut plants. Tilling readily kills seedlings. Order plants may regenerate from cut stems.

Chemical Control

In 1992, there were reports of jimsonweed resistance to Photosystem II inhibitors at several sites in Indiana. For more information on herbicide resistance in jimsonweed please see: http://www.weedscience.org/Summary/USpeciesCountry.asp?lstWeedID=75&FmCommonName=Go

Examples of herbicides that can be used to manage jimsonweed

Consult herbicide labels for additional rate, application, and safety information. Additional herbicide information can be found at http://www.greenbook.net.

Herbicide Active Ingredient trade name	Mode of Action	Product per Acre	Application Time or Growth Stage
Alfalfa
Imazethapyr	Group 2 (Inhibition of acetolacetate synthase ALS)
*Pursuit		3-6 ounces/A	Apply postemergence to seedling alfalfa in 2nd trifoliate leaf stage or larger, when jimsonweed is 1-3 inches tall.
Dry Beans and Dry Peas
Imazamox	Group 2 (Inhibition of acetolacetate synthase ALS)
*Raptor		4 ounces/A	Apply post-emergence prior to bloom stage but after dry beans have at least one fully expanded trifoliate leaf and dry peas have at least 3 pairs of leaves. Apply when jimsonweed is at 3 inches in height.
Grass Grown for Seed
Clopyralid; 2,4-D	Group 4 (synthetic auxins)
*Curtail		2 - 4 pints/A	Apply to well established grasses prior to the boot stage and when jimsonweed is actively growing.
Wheat and Barley
Clopyralid; 2,4-D	Group 4 (synthetic auxins)
*Curtail		2 - 2.6 pints/A	Apply in the spring to actively growing wheat or barley once 4 leaves have unfolded on the main stem and tillering has begun up to the jointing stage (first node of main stem detectable). To control or suppress listed weeds, make application after maximum emergence of the target weeds but before they exceed 3 inches in height.
Clearfield® Wheat
Imazamox ammonium salt	Group 2 (Inhibition of acetolacetate synthase ALS )
*Beyond		4 - 6 ounces/A	In spring wheat, apply at the 4-leaf stage prior to jointing when weeds are less than 3 inches tall. Apply to winter wheat when jimsonweed is under 3 inches tall.
Rangeland and Pasture
Dicamba	Group 4 (synthetic auxins)
*Clarity		8 - 24 ounces/A	Apply 8-16 ounces when plants are small and actively growing. Apply 16-24 ounces to established weed growth.
Glypohosate	Group 9 (Inhibition of EPSP synthase)
*Roundup Original Max		22-32 ounces/A	Apply when jimsonweed is 12-18 inches tall.

The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.

References

For more information and images please visit IPM Bugwood: http://www.ipmimages.org/search/action.cfm?q=jimsonweed&Start=1&results=44