Partial growth analysis of soybeans stressed by simulated green coverworm defoliation and velvetleaf competition.

Reference Report for IND84042146

Title:	Partial growth analysis of soybeans stressed by simulated green coverworm defoliation and velvetleaf competition.
Authors:	Higgins, R.A., Pedigo, L.P., Staniforth, D.W., Anderson, I.C.
Source:	Crop Sci. 1984, 24(2):289-293
Abstract:	Dry weight accumulation and allocation by soybean [Glycine max (L.) Merr. ‘Amsoy 71’] under selected combinations of competition with velvetleaf [Abutilon theophrasti (Medic.)] and simulated defoliation by the green cloverworm [GCW, Plathypena scabra (F.)] were evaluated with traditional growth analysis techniques in a 2-year field study. Discernible effects of weed-stress were restricted to soybeans grown in weed-proximate locations for 42 days or more after emergence. In general, weed-proximate soybeans stressed season-long by velvetleaf exhibited smaller dry weights, mean crop growth rates (CGR), and mean relative growth rates (RGR) than those in plots where velvetleaf competition was terminated within 5.5 weeks of emergence. In. cremental defoliation, equivalent in phenology and intensity to 120 GCW larvae/m of row did not substantially influence reproductive dry weights or reproductive growth rates within 75 days of soybean emergence. However, leaf and stem components were sometimes reduced within this period. Velvetleaf competition and simulated GCW defoliation did not interact significantly in this study.

Funded by the USDA-ARS. Developed by the USDA-ARS SoyBase and Legume Clade Database group at the Iowa State University, Ames, IA

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