Weed of the month: Prickly sida

  • wom-prickly-sidaCommon name: Teaweed
  • Scientific name: Sida spinosa
  • Grass or broadleaf: Summer annual broadleaf
  • Native to the eastern two-thirds of the United States and prevalent across the South
  • One of the most troublesome weeds in peanuts, cotton and soybeans in the Southern states1
  • Emerges as temperatures warm in early spring, continuing through September, and can grow to 3 feet in height
  • Can produce approximately 1,000 seeds in a single weed
  • Can reduce yield potential by as much as 10 percent2

A fact that may surprise you

  • The common name of prickly sida is teaweed because the weed’s leaves look a lot like the leaves of a tea plant.

Fast facts from David Hillger, Enlist field specialist, Dow AgroSciences

To correctly identify prickly sida when scouting, look for the following plant-distinguishing features:

  • The seedling’s cotyledons are heart-shaped and covered with small hairs.
  • Leaves are small, ¾ to 2 inches long, oval-shaped with toothed margins and are alternately positioned on branched stems.
  • Prickly sida flowers are pale yellow with five petals.
  • Stems have small, blunt spines at the leaf and branch bases.
  • A member of the mallow family, prickly sida is related to velvetleaf and cotton.

Resistance statistics*

  • According to TakeActionOnWeeds.com, herbicide-resistant prickly sida has been documented in Georgia.
  • Since the early 1990s, prickly sida has shown resistance to ALS inhibitors (Group 2).

*Resistance confirmation does not necessarily include all weeds and may vary among different areas of each state.

Prickly sida control/management tips:

Hillger says:

  • Plant soybeans early in narrow rows with high seeding rates.
  • Apply a preplant burndown followed by a soil-applied preemergence herbicide.
  • Use a postemergence herbicide treatment to control prickly sida before they get too large for adequate control.
  • Prickly sida experiences increased germination during high temperatures.

General tips to manage herbicide-resistant weeds

Growers in the Midwest and Midsouth face some of the most difficult-to-control weed species. Taking the following steps during the season can help manage weed resistance issues:

  • Develop an integrated weed management plan that delivers multiple modes of action throughout the season. With resistance increasing, the Enlist weed control system allows growers to use multiple postemergence modes of action, including glufosinate, glyphosate and a new 2,4-D in soybeans and FOPs, glyphosate and a new 2,4-D in corn.
  • Use full rates of herbicides during applications. Do not use partial rates or trim back for any reason, including cost.
  • Spray when weeds are small. Although it can be challenging because of weather and other factors, this is the ideal application timing.
  • Scout fields regularly to identify weeds when they are small and easy to control.

Dow AgroSciences weed control solutions:

Corn
SureStart® II herbicide
Resicore® herbicide
Keystone® NXT herbicide
Keystone® LA NXT herbicide 

FulTime® NXT herbicide
Surpass® NXT herbicide 
Durango® DMA® herbicide
Duramax® herbicide
Enlist Duo® herbicide, as part of the Enlist weed control system

Soybeans
Sonic® herbicide
Surveil® herbicide
Durango® DMA® herbicide
Duramax® herbicide
Enlist Duo® herbicide, as part of the Enlist weed control system

Additional information:
More information can be found online at:
Prickly Sida (Teaweed) Management in Soybeans — United Soybean Board

1Virginia Tech Weed Identification Guide. 2016. Prickly Sida or Teaweed: Sida spinosa.
https://oak.ppws.vt.edu/~flessner/weedguide/sidsp.htm

2United Soybean Board. 2016. Prickly Sida (Teaweed) Management in Soybeans.
http://unitedsoybean.org/wp-content/uploads/54403_01-FactSheet_PricklySida_LR.pdf

®™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. FulTime NXT, Keystone LA NXT and Keystone NXT are federally Restricted Use Pesticides. Duramax, Durango DMA, Enlist Duo, FulTime NXT, Keystone LA NXT, Keystone NXT, Resicore, Sonic, SureStart II, Surpass NXT and Surveil are not registered for sale or use in all states. FulTime NXT, Keystone LA NXT, Keystone NXT, Resicore, SureStart II and Surpass NXT are not available for sale, distribution or use in Nassau and Suffolk counties in the state of New York. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions. ©2016 Dow AgroSciences LLC