ARC Home I SJAR Home I About SJAR I Article Order Info. I Contribution to SJAR
Sudan Journal of Agricultural Research
Biological studies of Amaranthus viridis L. and Sinapis
arvensis L
Mukhtar A.M., Eltahir S. A., Siraj O.M. and Hamada A. A
Abstract:
A study was conducted to investigate some biological aspects of the weed
species Amaranthus viridis L. and Sinapis arvensis L.
Seeds were sown in field plots on 3 November 2003 at Dongla area,
Northern State. At flowering plant height, root length and days to 50%
flowering were recorded. At maturity number of seeds/plant was counted.
Laboratory experiments included the effects of constant temperature (5 -
45°C) and alternating temperature of 30/20 °C, simulated drought (0 to
-15 bar) and sowing depth (0 - 5 cm) on seed germination and seedling
emergence. Germination of both species commenced within 24 h, rapidly
increased after 3 days and reached a maximum with 3 – 9 days. Both
species are annual herbs 90 -92 cm high, with 22 - 30 cm root length,
reached 50% flowering within 52 – 54 days and completed their life span
after 99 -101 days. A. viridis produced 1050000 seeds/plant,
while that for S. arvensis produced only 650. Seed germination of
both species, was inhibited at 5 and 45 °C. Germination of A. viridis
occurred at 15 °C, while that for S. arvensis commenced at 10 °C.
The optimum temperature for germination of A. viridis was at 30
or 30/20 °C, while that for S. arvensis was 20 °C. The maximum
temperature in both species was 40°C. Germination decreased with
increased osmotic pressure. In A. viridis seeds it took place at –3 and
–6 bar, while that of S. arvensis was displayed up to –12 bar.
Germination was considerable (94-99%) at sowing depths of 0 - 2 cm,
moderate (70-88%) at 3 cm depth and was significantly reduced at 4 and 5
cm depth. Seedlings failed to emerge at 4 or 5 cm depth. Maximum
emergence was attained at 0 - 0.50 cm depth. Emergence of A. viridis
was generally higher than S. arvensis.
Keywords:
Sudan Journal of Agricultural Research Vol. 8 (2007) PP. 9-16
