Document Type
Article
Publication Date
1-2005
Abstract
Do weeds that emerge later in the season justify additional control costs'? If crop yield is not reduced or few or no seeds arc added to the soil seed hank, then no control may he needed. Eight weed species were sown in corn (Zea mays L.) and soybean I Glycine max (L.) Mcrr.l (i) before crop emergence, (ii) at crop emergence, (iii) at V-1, and (iv) at V-2 stages of crop growth in 2002 and 2003. Weed seed was sown close to the crop row and thinned to 1.3 plants m 2• Weed growth and fecundity were influenced by species, time of planting, and year. Only barnyarclgrass (Echinochloa crus-galli L.), rcclroot pigwced (Amaranthus retniflexus L.), and vclvetlcaf (Abutilon theophrasti L.) survived to produce seed. Plants from the pre-emergence seeding had the largest canopy and produced the most seeds. Harnyardgrass had maximum canopy cover in early .July in corn and late .Inly in soybean hut only produced seed in corn. Rcclroot pigweecl and vclvctleaf had maximum canopy cover in late August or midSeptember, and some plants from most seeding elates survived and produced seed in both corn and soybean. However, plants that grew from seed sown at V-1 and V-2 crnp grnwth stages did not reduce yield or biomass of adjacent crop plants, had low fecundity, and may not warrant treatment. Control may be necessary, however, to prevent yield losses if weeds arc present at high densities or to prevent establishment of uncommon species.
Publication Title
Agronomy Journal
Volume
97
Issue
1
First Page
294
Last Page
302
Format
application/pdf
Publisher
American Society of Agronomy
Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S.
Recommended Citation
Clay, S. A.; Kleinjan, J.; Clay, D. E.; Forcella, F.; and Batchelor, W., "Growth and Fecundity of Several Weed Species in Corn and Soybean" (2005). Agronomy, Horticulture and Plant Science Faculty Publications. 189.
https://openprairie.sdstate.edu/plant_faculty_pubs/189