The Field experiments were conducted out during the two
successive winter seasons of 2012/2013 and 2013/2014 at the
Experimental Farm (Demo) of the Faculty of Agriculture, at Fayoum
University, Egypt .The aim of these experiments was to evaluate yield
and yield components of some wheat cultivars under different Sowing
Dates and different irrigation intervals . The experiment was laid out
in split - split plot design with four replicates and comprised of three
dates of Sowing, namely 1st November, 15th November and 30th
November in main plots and three irrigation intervals, namely, I1
Irrigation every 21 days, I2 Irrigation every 28 days, I3 Irrigation every
35 days, in sub- plots and three wheat cultivars namely, Sakha 93,
Sakha 94, and Sids 12 in sub-sub-plots. The results of wheat cultivars,
irrigation intervals and different sowing dates mostly showed
significant differences (P < 0.05) for yield and yield components. The
cultivar Sids 12 scored the first rank in all characters. Irrigation
intervals showed significant differences on all characters except
number of spikelets/spike and irrigation every 28 days recorded the
highest values in most characters followed by every 35days. The
sowing dates shown significant effect on all traits except harvest index
and the highest values were obtained when cultivars sown in 15th
November in most characters. The results indicated that crop planted
on November 15, produced higher grains yield as compared to late and
early planting. This indicated that late sowing shortest the development
phases of wheat and adversely affected the grains development and
thus the grain yield. On the other hand, The interactions effect between
sowing date and irrigation intervals, sowing date and wheat cultivar,
irrigation intervals and wheat cultivar and sowing date x irrigation
intervals x wheat variety remained significant on all traits except the
interaction between irrigation intervals and wheat variety on spike
length, weight of grain/spike, seed index and harvest index. Generally,
Sids12 under sowing on 30th November and irrigation every 28days
followed by the same variety when sowing on 15th November and
irrigation every 35days surpassed on the other tested treatments in
grain yield/fed. (2.97 and 2.93 t/fed.) respectively.