Figure legends
Figure 1. Illustration of the grass treatment used in the field
experiment from the top-view (left) and a cross-section (right), modeled
after (Emily Green-Tracewicz et al., 2011) as modified by (Schambow et
al., 2019). Sugar beet was planted into the center ring, and was allowed
to grow using the full depth (35 cm) of the 21-liter pail. Grass roots
were constrained to the top 7.5 cm and outer 9 cm of the pail, and were
isolated from the sugar beet roots using plastic. Grass was clipped as
needed to minimize any direct shading of the sugar beet plant in the
center. For the soil treatment, the design was the same, except no grass
was planted into the potting media in the outer ring. Drawing by Jessica
Perry.
Figure 2. Typical sugar beet growth porgession during the
growing season. Growing degree days (GDD) calculated using the
parameters described in Equation 1. The 240, 480, 720, 920, and 1200 GDD
correspond to approximately 15, 30, 45, 75 days after planting sugar
beet. Drawing by Jessica Perry.
Figure 3. Relationship between duration of weed presence and
number of sugar beet leaf angle at ~700 growing degree
days (GDD; ~45 days after planting) (A and B), number of
leaves at harvest (C and D), and leaf area (E and F) in a field study
conducted from 2015 to 2019, Laramie WY. Black lines show the fixed
effects predictions, colored lines correspond to individual years.
Panels on the left (A, C, and E) included treatments in which weeds were
present at sugar beet emergence until removed later in the growing
season. The dotted line in figure C and E indicate a break in the linear
trend in the absence of the weed-free treatment. Panels on the right (B,
D, and F) included treatments in which weeds were added at various times
during the season and allowed to remain until harvest. Regression
equations are from the linear mixed-effects model. P-values in
parenthesis are for the reduced model that did not include the
season-long weed-free treatment.
Figure 4. Sugar beet shoot growth in the weed-free (left) and
weedy (right) at 41 days (648 growing degree days) in the field
experiment in 2016, Laramie WY.
Figure 5. Relationship between sugar beet leaf position and
leaf width (A), leaf area (B), petiole length (C), leaf length (D), and
petiole proportion of total leaf length (E) at harvest in a greenhouse
study conducted from Nov 11, 2018, to Feb 5, 2019, Laramie WY. Leaf pair
1 indicates the oldest leaf pair. Bars and shaded area indicate 95%
confidence intervals.
Figure 6. Relationship between duration of weed presence and
sugar beet leaf biomass (A and B) and root biomass (C and D) in a field
study conducted from 2015 to 2019, Laramie WY. Black lines show the
fixed effects predictions, colored lines correspond to individual years.
Panels on the left (A, C) included treatments in which weeds were
present at sugar beet emergence until removed later in the growing
season. The dotted line A indicates a break in the linear trend in the
absence of the weed-free treatment. Panels on the right (B, D) included
treatments in which weeds were added at various times during the season
and allowed to remain until harvest. Regression equations are from the
linear mixed-effects model. P-values in parenthesis are for the reduced
model that did not include the season-long weed-free treatment.