Efficacy of Herbicides When Spray Solution Application Is Delayed

Table 2

Visible estimates of common ragweed control by lactofen and Palmer amaranth control by atrazine, imazethapyr, and 2,4-D 4 weeks after application at the manufacturer’s suggested weed size and 4 and 8 days after this weed size using spray solutions mixed the day of application or 4 or 8 days prior to application^a.

Timing of application after optimum weed size	Timing of solution preparation prior to application	Visible control
		Common ragweed	Palmer amaranth
		Lactofen	Atrazine	Imazethapyr	2,4-D
Days	Days	%
0	0	97^a	85^a	87^a	92^a
4	0	93^b	79^ab	85^a	89^a
4	4	95^ab	87^a	83^ab	88^a
8	0	97^a	68^b	77^b	77^b
8	8	97^a	68^b	74^b	75^b

aMeans within a weed species and herbicide combination followed by the same letter are not different at 𝑃≤0.05.
The letters (a, b, c, ab, and bc) following the means in the table are used to differentiate between the numbers in terms of statistical differences. Numbers may be different numerically, but if they have the same letter, they are not statistically different because of variation in the biological system.