This investigation aimed to study the response of some corn varieties and
hybrids (Giza 2, T.C. 320,t.c. 310, D.C.215 and D.C. Tabba) to water stress [Irrigation
interval days such as 15 days(control), 21 days (low stress), 28 days (mid stress), and
35 days (sever stress)] during germination, growth and yield. For achieving this
objective lab. Experiment using osmotic pressure treatments by Menitol solution
caused 5,7,9,11 and 13atmospheres, and two field experiments were carried out. A
split-plot design with three replications was used, where irrigation treatments occupied
the main plots, meanwhile the sup-plots were devoted to the corn cultivars.
Lab. results indicated that corn cultivars vary significantly in germination velocity and
germination capacity. Intermediate osmotic pressures (5, 7 and 9 atmospheres) were
sometimes simulative, but high osmotic pressures (11 and 13 atmospheres)
decreased germination velocity and capacity. D.C. 215 and D.C. Tabba showed the
highest values of germination velocity and capacity under different osmotic pressure.
Field experiments indicated that increasing irrigation interval from 15 to 21 days was
not effective except in Giza 2 variety. However, significant decreased in yield and
other characters occurred at 28 and 35 days intervals. T.C. 320, T.C. 310, D.C. 215
and D.C. Tabba showed variable insignificant yield differences in both seasons. Giza
2 was significantly of lower yield than D.C. 215, D.C. Tabba (1998) and T.C.
310(1999). The results showed that new water regimes(21 days &28 days
withT.C.310) may be used to save about 50% of corn irrigation water but more detail
studies are needed for verification.