Question

A researcher wanted to test the impact of four different herbicides on the ability to control weeds in turf grass. The number of weeds/m² were counted after treatment with the herbicides. Below is the data, summary statistics, and the resulting ANOVA.

ANOVA: Two-factor without replication

	Block 1	Block 2		Block 3		Block 4
Herbicide A	20	20		20		21
Herbicide B	8	9		10		3
Herbicide C	22	20		22		19
Anova: Two-Factor Without Replication
SUMMARY		Count	Sum		Average	Variance
Herbicide A		4	81		20.25	4.92
Herbicide B		4	30		7.50	1.67
Herbicide C		4	83		20.75	8.92
Block 1		3	53		17.67	102.33
Block 2		3	46		15.33	44.33
Block 3		3	47		15.67	60.33
Block 4		3	48		16	37
ANOVA
Source of Variation		SS	df		MS	F	P-value		F crit
Rows		451.17	2		225.58	36.75	0.00		5.14
Columns		9.67	3		3.22	0.52	0.68		4.76
Error		36.83	6		6.14
Total		497.67	11

What is the value for the LSD (0.05) for comparison of herbicide treatments?

a. LSD= 5.14 SQRT 2(222.58)/4

B. LSD= 2.447 SQRT 2(225.58)/4

C. LSD= 5.14 SQRT 2(6.14)/4

D. LSD= 2.447 SWRT 2(6.14)/4

Answer 1

For = 0.05, df Error = 6, = 2.447

For herbicide treatments, n1 = n2 = 4

MS Error = 6.14

Thus,

The answer is,

D. LSD= 2.447 SWRT 2(6.14)/4