Table 3: Percent reduction in soybean yield caused by season-long interference by Palmer amaranth in field experiment.a,b

Palmer amaranth biotypeYield reduction

%
Individual Palmer amaranth biotypesc
 Emanuel (GR)24a
 Macon (GR)17b
 Wayne (GR) 16b
 Crisp (GS)24a
 Emanuel (GS)22a
 Johnston (GS)24a
Palmer amaranth biotypes grouped by response to glyphosated
 GR19z
 GS23y

a Data are pooled over five 30 cm distance increments from Palmer amaranth and runs (years) of the experiment. Abbreviations: GR, glyphosate resistant; GS, glyphosate susceptible.
b Means within a parameter and analysis followed by the same letter are not significantly different according to Fisher’s Protected LSD test at 𝑃 0 . 0 5 .
c Consists of six Palmer amaranth biotypes.
d Consists of a group of three glyphosate-resistant and a group of three glyphosate-susceptible Palmer amaranth biotypes.