Interactions of Nitrogen Source and Rate and Weed Removal Timing Relative to Nitrogen Content in Corn and Weeds and Corn Grain Yield

Table 2

Palmer amaranth density as impacted by the interaction of environment and N source and environment and average weed height at timing of weed removal.

Treatment factor	2011		2012
	Clayton	Rocky Mount	Clayton	Rocky Mount
	Number/0.25 m^2
Nitrogen source
Urea ammonium nitrate	70	18	96	1
Sulfur-coated urea	57	21	156	0
Composted poultry litter	104	17	157	0
Average weed height at timing of removal (cm)
8	100	19	95	0
16	55	18	85	0

Means within a treatment factor and combination of location and year followed by the same letter are not significantly different according to Fisher’s protected LSD test at .
Data are pooled over N rates and average weed height at timing of removal.
Data are pooled over N sources and N rates.