Two field experiments were carried out at farm in Abo Hussein Village, Abo Kebeer district, Sharkia Governorate, during the two successive winter seasons of 2005/2006 and 2006/2007 to study the response of sole and relay intercropping wheat (Triticum aestivum vulgare L.) to the effect of the times of two last irrigations and ridge width as well as their interaction on yield and its attributes of wheat.
The obtained results could be summarized as follows:
The highest values of all studied characters were resulted from giving fourth and fifth irrigations of sole or relay intercropping wheat at 15th April and 1st May, respectively, excluding number of spikes/m2 of sole wheat in the second season, number of spikelets/spike of relay intercropping wheat in the second season and straw yield/fed of sole wheat in both seasons.
Sowing both sole and relay intercropping wheat on wide ridges (100 cm) produced the highest values of plant height and grain yield of relay intercropping wheat in both seasons, number of spikes/m2 and straw yield/fed of sole wheat in both seasons, spike length, number of spikelets/spike, number of grains/spike and 1000 – grain weight of sole and relay intercropping wheat in both seasons..
The highest values of land equivalent ratio (LER) and area time equivalent ratio (ATER) were resulted from performing fourth and fifth irrigations of wheat at 15th April and 1st May and sowing cotton on 15th April in both seasons. Sowing both wheat and cotton on ridges with width of 80 cm was the most favorable treatment that produced the highest average of LER and ATER in the first season. Whereas, in the second season sowing both wheat and cotton on ridges with width of 90 cm produced the highest average of LER and ATER.
The interaction between studied factors had insignificant effect on all studied characters in both growing season, except number of grains/spike of sole wheat in the first season only.
Results of this study show that yields and its attributes of sole or relay intercropping wheat grown under the environmental conditions of Sharkia district can be maximized due to carrying out fourth and fifth irrigations at 15th April and 1st May, respectively and sowing on ridges with width of 100 cm.