This study was carried out to determine the effect of the combination of
three levels of available soil moisture stress (40.60 and 80% ASMD). three
maize cultivars (T.W.C. 310, Karnak and Giza 2) and three Icvcls of zinc
sulphate as foliar application (0.0.3% 0.6% ZnSO4) on growth characters. Three
field cxperimcnts were conducted at Sakha Agricultural Research Station. Kafr
El-Shcikh Governorate. Egypt in 1988, 1989 and 1990 seasons. The
ecperimcntal design was split-split plot with four replications. The results were
summarized as follows:
The average values of dry weight. leaf area/plant and leaf area index at
60,75 and 90 days from planung. the percentage of ears at 90 days after sowing.
chlorophyll a, carotenoids. crop growth rate, net assimilation rate, plant height.
ear height and stem diameter were significantly decreased by increasing soil
moisture depletion from 40 lo 80% in combined analysis over three seasons.
There was a significant delay of silking time by increasing soil moisture
T.W.C. 310 cultivar surpassed significantly Giza 2 and Karnak
cultivais in dry weight/plant at 60. 75 and 90 days from sowing. the percentage
of stem, leaf area/plant and leaf area index at 75 and 90 days after sowing. crop
growth rate, plant height. ear height and stem diameter. Karnak cultivar gave
the highest for the percentage of leaves at 75 and 90 days from so ،ng.
chlorophyll a and number of days to 50% silking. Gua 2 cultivar surpassed
significantly the other cultiv ars in the percentage of ears and stein/plant at 75
and 90 days from sosing time.
The mean ‘alijes of dr wcight aI 90 da>s from soing. leaf area/plant
and leaf area index at 60 and 75 da> after sowing and stem diameter
significantly increased by increasing hic lcvcl of tinc sulphate up to 01%.
whereas the number of days lo 50% silking significantl> decreased b>
application zinc sulphate as foliar up to 0.3%.
T.W.C 110 cultivar with irrigation at 40% depIction in available water
or with applied 0.1% ZnSO4 gave the highest percentage of stem. chloroph>ll a
and the ratio of chloroph>Il ab The interaction between atcr sirces. cultiars