A field experiment was conducted during two successive seasons
of 2003/2004 and 2004/2005 at Giza Agric. Res. Station. The study
aimed to identify the most effective coefficient of daily pan
evaporation records (selected from 1.4, 1.2, 1.0 and 0.8) in scheduling
the irrigation for some wheat cultivars namely Sids 1, Gemmeiza 7,
Sakha 93 and Giza 168, in order to maximize crop and water
productivity. The obtained results could be summarized as follows.
1- The growth characters of plant height and leaf area index were
significantly influenced due to the adopted irrigation regimes and
generally, tended to increase as the coefficient of pan evaporation
records increased. In addition, Gemmeiza 7 cultivar surpassed the
other tested wheat cultivars to increase such characters.
2- No of grains/spike and 1000-grain weight traits exhibited similar trends
since scheduling irrigation according to 1.2 pan evaporation
coefficient(PEC) resulted higher figures for such characters.
Gemmeiza 7 surpassed the other tested wheat cultivars to increase
such traits. The trait of No. of spikes/m2 exhibited different trend since
higher values were recorded under 1.0 and 1.2 PEC in the first and
second seasons, respectively. Sids 1 and Gemmeiza 7 cultivars were
superior to produce the highest No. of spikes/m2 in the first and
second seasons, respectively.
3- Straw yield seemed to increase with increasing the value of PEC and
Gemmeiza 7 cultivar is still superior to increase such trait more than
the other tested wheat cultivars. The highest grain yield was obtained
as irrigation was practiced according to 1.2 PEC and tended to reduce
under the other assessed PEC treatments and this finding was true in
the two seasons.
4- All of agronomic, yield and yield components traits were significantly
influenced as the adopted irrigation regimes interacted with the wheat
cultivars under study.
5- Number of applied irrigations and water consumptive use (CU) were
increased as the value of PEC increased. Moreover, CU for wheat crop < br />was significantly differed due to wheat cultivars, and Sids 1 consumed
more water than the other tested wheat cultivars.
6- The lowest water use efficiency (WUE) was recorded under 1.4 PEC,
comparable to the other tested PEC values. Values of PEC i.e. 1.2, 1.0
and 0.8 exhibited similar WUE values in first season, while in the
second season, WUE tended to decrease as PEC value decreased.
Gemmeiza 7 surpassed the other tested wheat cultivars to produce
more grain yield per the consumed water unit, and this was true in the
two seasons of study.