n this work, the effects of a hydrogen peroxide (H2O2) pretreatment on the germination and early seedling growth of barley under salt (NaCl) and temperature (20º, 5º, 30º and 35ºC)conditions was studied. H2O2 enormously removed the germination-elaying and inhibiting effects of temperature increases. In addition, it was rather effective on alleviation of the
reductive effects of temperature increases on the parameters of growth such as the
percentages of coleoptile emergence, elongations of radicle, and coleoptile and fresh weights
(FWs) of the seedlings. H2O2 pretreatment became very successful in the overcoming of the germination-delaying and preventing effects of the increases in both salt and temperature
levels. It markedly alleviated the inhibitions of salt on seedling growth at all temperatures as
well. H
2
O
2
both removed the blockage of abscisic acid (ABA) on the germination and shortened
the time required for germination at 20ºC, an optimal temperature, by its influsion into the
seeds with pretreatment or its presence in the medium of germination. On the other hand,
H
2
O
2
relatively alleviated ABA inhibitions on the radicle elongations and FWs while it had no
effect on ABA suppression on the emergence percentage and elongation of the coleoptile