Two field experiments were carried out at El-Gemmeza Agric. Expt. Sta., El-Gharbia Governorate, Middle Delta, during 1997/1998 and 19981/1999 seasons to study the effect of some tillage systems including no-till (as a control), Chisel plowing (16-18 cm), moldboard plowing (18-20 cm), subsoiiing + chisel plowing and subsoiling + moldboard plowing and weed conlrol treatments (Arelon, Granstar, Grasp and unweeded check) on the growth and yield of wheat and on the spread of weeds in wheat plots. The results of the combined analysis of both seasons could be summarized as follows:
Bulk density and salinity of the soil were not significantly affected by tillage treatments in both seasons. Whereas, soil porosity % was affected by tillage treatments in the first season. The highest porosity % was recorded by subsoiling + moldboard plowing. Subsoiling + moldboard plowing significantly surpassed the 4 other systems, and Arelon was significantly superior to the other 2 herbicides in depressing weeds at 60, 90 and 120 days from sowing (DPS). The significant interaction indicated superiority of subsoiiing + moldboard plowing with Arelon in depressing weed infestation. Plant height and LAI at 60 snd at 120 DPS as well as dry matter accumulation at 120 DPS were significantly affected by tillage and weed control treatments as well as their interaction. The best treatment was that including subsoiling + moldbonrd plowing followed by moldboard plowing (alone). Arelon was the best herbicide affecting those traits. Combining Aielon with subsoiling + moldboard plowing recorded the maximum values for those traits. Subsoiling + moldboard plowing significantly surpassed the other 4 tillage systems in affecting all No. of spikes/m2, 1000-kernel weight, No. of spikelets/spike, spike length, No. of grains/spike, spike weight, grain weight/spike and yield of straw and grain/fad. Also, Arelon was the best herbicide. Combining subsoiling + moldboard plowing with Arelon recorded the highest values for those traits. |
