Table 4: Effect of weed competition period on aboveground crop biomass production in aerobic rice variety AERON 1 at different growth stages in both seasons (off-season 2010 and main season 2010/2011 (g/m2)).

Weed competition period Off-season 2010Main season 2010/2011
Panicle initiation stageHeading stageHarvestPanicle initiation stageHeading stageHarvest

Weedy until 2 WAS191.77a364.35b660.71ab201.89a328.23ab669.60b
Weedy until 4 WAS83.20c293.42c631.00b81.40c306.60b652.00b
Weedy until 6 WAS80.32c215.00d443.53d76.00c241.14c431.30d
Weedy until 8 WAS77.43c119.42f235.42e75.28c111.00e205.55e
Weedy check77.59c108.29f169.00f75.67c91.59e130.49f
Weed-free until 2 WAS165.30b158.00e247.48e151.35b169.47d253.67e
Weed-free until 4 WAS208.57a302.66c553.00c185.48a302.62b589.07c
Weed-free until 6 WAS208.98a364.7b664.36ab197.73a336.67ab654.23b
Weed-free until 8 WAS210.10a381.85ab673.00ab204.16a353.72a687.58ab
Weed-free check209.00a406.00a679.45a202.31a359.87a729.33a

Within a column for each factor, means sharing same alphabets are not significantly different at 𝑃 = 0 . 0 5 probability level according to least significant difference test.
WAS = weeks after seeding.