Aspects of Velvetleaf (Abutilon Theophrasti Medik.), Jimsonweed (Datura Stramonium L.) and Common Cocklebur (Xanthium Strumarium L.) Interference With Soybeans

Velvetleaf (Abutilon theophrasti Medik.), jimsonweed (Datura stramonium L.) and cocklebur (Xanthium strumarium L.) are broadleaf weeds common in midwest soybean fields. Cocklebur causes greater yield reductions than velvetleaf and jimsonweed at equivalent densities. Cocklebur has a greater proportion of its leaves below the top of the soybean canopy where velvetleaf and jimsonweed have few to no leaves. Competititve effects of cocklebur may involve shading within the soybean canopy and space exclusion caused by its lower leaf canopy. Field and laboratory experiments were conducted to determine the causes for differences in leaf canopy of weeds below the top of the soybean canopy, to determine the importance of space exclusion and shading by weed leaves within the soybean canopy on soybean yield and other parameters, and to determine the cause for the apparent shade-tolerance exhibited by cocklebur.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Agronomy

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

1987

Author dc:creator

• Regnier, Emilie Elisabeth

• Agriculture, Agronomy

Identifier

(UMI)AAI8711860

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71632