HPIPM:Velvetleaf

Taxonomy

Domain	Eukarya
Kingdom	Plantae
Phylum	Magnoliophyta
Class	Magnoliopsida
Superorder	Rosanae
Order	Malvales
Family	Malvaceae
Genus	Abutilon

Scientific Name

Abutilon theophrasti

Common Name

velvetleaf

Velvetleaf (Abutilon theophrasti)

Compiled by Jeff Edwards, University of Wyoming, Goshen County Extension.

and Marjolein Schat, Montana State University from the following sources:

http://na.fs.fed.us/FHP/INVASIVE_PLANTS/weeds/velvetleaf.pdf

http://plants.usda.gov/java/profile?symbol=ABTH

Identification and Life Cycle

Velvetleaf (Abutilon theophrasti) is an introduced annual in the mallow family (Malvaceae). Velvetleaf is also knows as Indian mallow, China-jute, pie-maker, abutilon-hemp, buttonweed, and velvet weed. The plant is erect and shrub-like with alternate heart-shaped leaves. Stems are have soft hairs and can grow up to 7 seven feet tall. Leaves are 2 to 6 inches long and wide, with dense hairs on both surfaces. Leaf margins are toothed and leaves emit an unpleasant odor when crushed. Flowers are solitary, yellow, are 1/2 to 1 inch wide, and have 5 petals. Seeds are produced in a circular capsule fruit approximately 1 inch in diameter with a ring of spines around the upper edge. Each capsule has a 10 – 15 seedpods that produce 5 - 15 seeds each. Velvetleaf has a fibrous taproot.

Habitats

Velvetleaf grows along roadsides, ditches, hillside slopes, riverbanks, disturbed areas, and cultivated fields.

Impacts

Velvetleaf causes the most concern in row crops, mainly soy bean, corn and cotton where it outcompetes the strongest cultivated plants for water and soil nutrients. Yield reductions of 20-34% have been attributed to velvetleaf in corn. Velvetleaf is also known to have allelopathic affects on the seed germination and seedling root elongation of other plants. Laboratory studies show that velvetleaf extracts depressed the germination and growth of alfalfa, maize, radish, soybean, and turnip seedlings.

Biology and Ecology

Velvet leaf reproduced from seed and seedlings emerge in spring and early summer. Seeds germinate from soil depths of 2 inches. Seeds that germinate on the soil surface die. Once the seedling emerges, a tap root develops, allowing the seedling to become quickly established. The seedlings exhibit rapid growth upon emergence, often exceeding the crop heights by mid-growing season. Velvetleaf blooms from late summer through early fall. Flowers are short lived. Each plant can produce 700 – 17,000 seeds. Seeds exhibit dormancy and can survive in the soil for over 50 years. Seeds can also remain viable after passing through animal digestive tracks.

Management Approaches

Prevention of formation of a seed bank is essential for controlling velvetleaf.

Biological Control

Ten fungal species and six insects have been reported to affect velvetleaf plants. There are several organisms that are being studied for possible use as biocontrol agents, though none are currently available for release. The scentless plant bug (Niesthrea louisianica) caused a 98% seed reduction. In addition Fusarium lateritium and Colletotrichum coccodes are mycoherbicides being studied for velvetleaf suppression. Rhizobacteria have also been studied for control of seedlings. Several root nematdes (Heterodera marioni, Medoidogyne ssp.) parasitized velvetleaf under greenhouse. Velvetleaf is a wild host to tobacco budworm (Heliothis virescens) and bollworm (H. zea), which feed on the terminal shoots, young leaves and immature fruits. However, these insects are serious crop pests and cannot be encouraged for control of velvetleaf.

Mechanical and Cultural Control

Close mowing is effective if mowed prior to seed production. Velvetleaf becomes less of a problem in no-till systems because the seed germinates on the soil surface and the seedlings do not survive. Hoeing is successful if the velvetleaf plants are less than 1/4" in height. Because velvetleaf can emerge from a 2" depth in the soil profile, it is difficult to remove with a rotary hoe once it is established.

Chemical Control

There are reports of velvet leaf resistance to Photosystem II inhibitors (HRAC Groups C1, C2, & C3) in Maryland, Wisconsin, Minnesota, and Michigan. For more information on herbicide resistance in velvetleaf, please see http://www.weedscience.org/Summary/USpeciesCountry.asp?lstWeedID=1&FmCommonName=Go.

When using herbicides alternate products with different modes of action to aid in resistance management. Currently there are at least 211 products registered for use on velvet leaf representing 11 of the 27 herbicide groups (defined Modes of Action).

Examples of herbicides that can be used to manage velvet leaf

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
Sorghum
Carfentrazone-ethyl	Inhibition of protoporphyrinogen oxidase (PPO)
*Aim EW		0.5 ounces	Apply when velvetleaf is less than 18 inches tall.
Alfalfa
Imazethapyr ammonium salt	Inhibition of acetolacetate synthase ALS (acetohydroxyacid synthase AHAS)
*Pursuit		4-6 ounces	Apply when velvet leaf is 3- 4 inches tall.
Glyphosate	Inhibition of EPSP synthase
*Roundup Original Max		22-32 ounces	This product may be applied before, during or after planting crops listed in this section. Applications must be made prior to crop emergence. Apply when velvetleaf is 6-12 inches tall.
Grass Grown for Seed
Clopyralid; fluorxypyr	Action like indole acetic acid (synthetic auxins)
*Widematch		1 – 1.33 pints	Apply to established grasses in the spring from the tiller stage prior to early boot stage. New grass seed plantings may be treated from the 2 true leaf stage to just before early boot stage of growth. Applications in the boot stage and beyond can result in increased potential for injury. Do not apply to bentgrass unless injury can be tolerated. Apply when weeds are actively growing, but before weeds are 4 inches tall.
Wheat, Barley, and Oats
Clopyralid; fluorxypyr	Action like indole acetic acid (synthetic auxins)
*Widematch		1 Pint	Apply when velvetleaf is less than 4 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 images please visit IPM Bugwood. http://www.ipmimages.org/search/action.cfm?q=velvetleaf&Start=1&results=59