Two field experiments were carried out at the Experimental Station of
the National Research Centre, Shalakan Kalubia Governorate during the two
seasons of 1998/99 and 1999/2000 to study the effect of sowing dates and
plant distance on associated weeds, growth characters, yield and its
components of Rapeseed plants (Brassica napus var. Pactol). The main
results were: The highest depressing effect at 75 days after sowing on annual
broad-leaved and total weeds were recorded by sowing date on is" Dec.
while Nov. is" and Nov. so" were the most effective treatments for
decreasing fresh weight of perennial and grassy weeds, respectively. At 105
days all data revealed that Nov. so" reflected the same significant response
to decreasing the fresh weight of broad-leaved, grassy and perennial weeds. For plant distance results show that fresh weight of associated weeds
of oil seed rape were significantly affected. Furthermore, sowing under plant
distance 10 cm between hills characterized by its inferiority significant values
for the fresh weight of associated weeds compared with the other two
distances 20 and 30 cm between hills at 75 and 105 days after sowing. In
addition, progressive increase in the distances from 10 to 20 and up to 30 cm
harvested the higher values from the fresh weight of associated weeds along
the growth period of plants. The interaction between sowing dates and plant
distance on annual grasses, perennial and total weeds significantly
responded at 105 days after sowing. The associated weeds caused its lowest
values under sowing date on oec.is" and plant distance 10 cm. All growth characters of rapeseed plants, had a significant response
to sowing dates along the growth period of plants. Vegetative growth
characters of oilseed rape plants give an evidence that plant height, number
of leaves/plant, leaves dry weight/plant, LA at 75 days after sowing and plant
height at 105 days increased significantly with Dec. is" sowing date. While
SLW at 75 days and number of leaves, number of branches/ plant, leaves,
stem, and total dry weights/plant, SLW, LA and LAI at 105 days responded
significantly on Nov. so" sowing date. Data indicated that plant density revealed significant effect on number and dry weight of leaves/plant, SLW, LA and LAI at 75 days, as well as number of branches/plant leaves dry weight, SLW and LAI at 105 days after sowing. The highest values of number, dry weight of leaves/plant and LAI at 75 days after sowing and number of branches, total dry weight/plant, LA and LAI at 105 days obtained from 10 cm between hills. The effect of interaction between sowing data on Nov. so" and plant distance 20 cm caused significant effect on SLW but 10 cm distance between hills had superior effect on LA and LAI under sowing date Nov. so" at 105 days after sowing. Data revealed that cultivating oil seed rape on Nov. so" was the most effective treatment to collecting the greatest significant values from each of number of pods, weight of pods, seeds weight/plant, oil %, seed and oil yield/fed. While is" Dec. sowing date produced the highest value of pod weight. Sowing oil seed rape at plant distance 10 cm between plants gave the highest significant values from weight of pod, seeds weight/pod, seed yield and oil yield/fed, while the distance 20 cm produced significant increases in seed oil %. On the contrary, significant superiority was found in number of pods, weight of pods and weight of seeds/plant at the plant distance 30 cm between plants. Data illustrated that interaction between sowing date Nov. so" and plant distance 30 cm gave maximum values from number of pods, weight of pods and weight of seeds/plant. With respect to the sowing date Dec. is" and plant distance 10 cm harvested the greatest values of seed yield and oil yield/fed.