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 levels of zinc
sulphate as foliar application (0.0.3% 0.6% ZnSO4) on growth characters. Three
field experiments were conducted at Sakha Agricultural Research Station. Kafr
El-Sheikh Governorate. Egypt in 1988, 1989 and 1990 seasons. The
experimental design was split-split plot with four replications. The results were
sununarized as follows:
The average values of dry weight, leaf area/plant and leaf area index at
60,75 and 90 days from planting, 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 to 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 signilicantly Giza 2 and Karnak
cultivars in diy 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 sowing,
chlorophyll a and number of days to 50% silking. Giza 2 cultivar surpassed
significantly the other cultivars in the percentage of ears and stem/plant at 75
and 90 days from sowing time.
The mean values of dry weight at 90 days from sowing. leaf area/plant
ana ieaf area index at 60 and 75 day after sowing and stem diameter
significantly increased by increasing the level of zinc sulphate up to 0.3%.
‘hereas the number of days to 50% silking significantly decreased by
ipplication zinc sulphate as foliar up to 0.3%.
r.w.c 310 cultivar with irrigation at 40% depletion in available water
wnn applied 0.3% ZnSO4 gave the highest percentage of stem. chlorophyll a
d the ratio of chlorophyll a+b The interaction between water strees.