Field Guide 
Weed Management Prickly Sida
Prickly Sida (Sida spinosa)
Crop Impacts: Soybeans and corn
About Prickly Sida:
Prickly Sida is considered a broadleaved herb. It is a summer annual plant, which develops very quickly once it has germinated. Prickly Sida is native to southern North America and has become an invader weed on people’s properties all around the world.
Family: Mallow family (Mavaceae)
Prickly Sida Scouting and Prevention:
Prickly Sida has a stem that is covered with very fine, white hairs. It branches occasionally and stands between 1 and 2 feet tall. They have decently sized leaves that are about 2 inches long and 1 inch across, alternating along the stem. They are ovate-oblong, with slightly gadded margins, covered in fine hairs. The Prickly Sida weed also produces little yellow flowers with 5 petals on them.
Common locations
- - Soybean fields
- - Agronomic crops
- - Pastures
Prevention
Pre-emergent herbicides such as simazine spread on corn crops works well, along with products containing atrazine. For control of Prickly Sida in soybean fields that provide over 94% control would be Valor XLT or Canopy DF plus 2,4-D. Products such as Sencor and Scepter also give excellent resistance against Prickly Sida.
Prickly Sida Control:
Cultural Control
Hoeing, hand pulling and mulching when the weather gets warm keeps the Prickly Sida from becoming a major problem. If there is an area where there is a heavy infestation, mowing before the seeds are set can be effective in getting rid of Prickly Sida. Low mowing will make it very difficult for Prickly Sida to recover, reducing the numbers of plants over time.
Chemical Control
Post-emergent herbicides work well for a broadleafed weed like Prickly Sida. Basagran plus 2,4-D provides good control on small plants; however, it is important to know that the control may be inconsistent. For post-emergent control on corn fields, dicamba, 2,4-D lightning and lgnite provide good control. As for control in soybean fields, application of glyphosate provides approximately 70 to 90% control of Prickly Sida.
Latin / Alternative Prickly Sida names:
- - Sida spinosa
- - Prickly fanpetals
- - Prickly sida
- - Teaweed
- - Indiana mallow
Additional Prickly Sida Resources
http://plants.usda.gov/core/profile?symbol=SISP
https://oak.ppws.vt.edu/~flessner/weedguide/sidsp.htm
http://www.illinoiswildflowers.info/weeds/plants/prickly_sida.htm
http://ipm.ncsu.edu/soybeans/weeds/weed_manage/weed_management7.html
http://www.karensgardentips.com/growing-garden-plants/weeds-growing-garden-plants/weeds-and-their-control-prickly-sida-sida-spinosa/
http://www.ppdl.purdue.edu/ppdl/weeklypics/3-14-11.html