Abstract: |
ater deficit is a decisive challenge that tremendously affects maize physiological functions
and productivity. Hence, it is crucial to ameliorate its tolerance to drought stress, in particular
under abrupt climate change and a growing population. The present study aimed to explore the
influence of exogenously sprayed moringa seed extract (Moringa oleifera) and α-tocopherol on physiobiochemical, morphological, and yield attributes of six diverse maize hybrids under three irrigation
levels in poor-fertility sandy soil. The applied irrigation regimes were based on estimated crop
evapotranspiration (ET) using the FAO Penman–Monteith equation. A split–split plot arrangement
with a randomized complete block design and three replicates was applied for different treatments.
Irrigation levels (100% ET, 75% ET and 50% ET) were established in the main plots, while foliar
applications (moringa extract and α-tocopherol) were located in subplots and the assessed hybrids (SC162, SC166, SC167, SC168, SC176, and SC178) in subsubplots. Mild (75% ET) and severe
(50% ET) drought stress gradually reduced the gas exchange, photosynthetic efficiency, water relations, and yield traits compared with well-watered conditions (100% ET). However, foliar application
of moringa seed extract or α-tocopherol was effective in reinforcing maize tolerance to drought stress
by enhancing the accumulation of osmoprotectants, improving antioxidant enzymes, and decreasing
levels of peroxidation of membrane lipids and electrolyte leakage compared to untreated control.
These positive impacts were reflected in boosting yield traits and crop water productivity under
water deficit conditions. The physiological and agronomic performance of the assessed maize hybrids
considerably varied under water deficit conditions. The hybrids SC168, SC176, and SC178 exhibited
the best performance under mild and severe drought conditions compared with the other hybrids.
Consequently, the integration of exogenously applied moringa seed extract or α-tocopherol with
tolerant maize hybrids such as SC168, SC176, and SC178 is an efficient approach to ameliorating
drought tolerance under water-scarce conditions in arid environments
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