Table 1. Mean squares from the analysis of variance of turfgrass quality (TQ), normalized difference vegetation index (NDVI),photochemical efficiency (Fv/Fm), shoot electrolyte leakage (ShEL), and root viability (RV) in creeping bentgrass treated with different levels of nitrogen under heat stress.

Day	Source	df	TQ	NDVI	Fv/Fm	ShEL	RV
1	Block	3	0.0040	0.0004	0.0012*
	Nitrogen	3	0.9740**	0.0069*	0.0002
	Error	9	0.0323	0.0012	0.0002
	R2		0.9099	0.6679	0.6952
15	Block	3	0.0990	0.0003	0.0057
	Nitrogen	3	0.1823	0.0006	0.0019
	Error	9	0.0867	0.0007	0.0096
	R2		0.5194	0.6301	0.7256
36	Block	3	0.0523	0.0032	0.0180
	Nitrogen	3	0.0612	0.0059	0.0069
	Error	9	0.0162	0.0043	0.0091
	R2		0.7223	0.4157	0.4787
50	Block	3	0.4769	0.0022	0.0067	33.1975	0.0058
	Nitrogen	3	2.2256**	0.0596**	0.0511**	841.0742**	0.0275**
	Error	9	0.2241	0.0022	0.0029	59.1975	0.0025
	R2		0.8502	0.9342	0.9067	0.8794	0.8626

**, * mean significant level at p<0.01 and 0.05, respectively.