Critical Period of Weed Control in Aerobic Rice

Table 3

Effect of duration of weed competition on density and dry weight of weeds in both seasons (off-season 2010 and main season 2010/2011).

Weed competition period	Off-season 2010		Main season 2010/2011
	Density (no./m^2)	Dry matter (g/m^2)	Density (no./m^2)	Dry matter (g/m^2)
Weedy until 2 WAS	879.67c	155.33de	950.33c	188.33e
Weedy until 4 WAS	1073.33b	215.00cd	1128.00b	239.0de
Weedy until 6 WAS	1241.00a	520.33a	1311.00a	548.33a
Weedy until 8 WAS	979.67b	503.00a	1033.33bc	532.33a
Weedy check	471.00d	390.00b	520.67d	431.67b
Weed-free until 2 WAS	473.00d	342.00b	506.00d	364.67c
Weed-free until 4 WAS	380.67d	256.67c	421.33d	286.0d
Weed-free until 6 WAS	206.00e	164.33de	224.33e	181.67e
Weed-free until 8 WAS	102.33f	107.33e	123.67e	101.33f

Data for weedy treatments were taken at the time of weed removal, whereas data for weed-free treatments were taken at the time of rice harvest.
Within a column for each factor, means sharing same alphabets are not significantly different at 𝑃=0.05 probability level according to least significant difference test.
WAS = weeks after seeding.