Utilization Efficiency of Growth Regulators in Wheat under Drought Stress and Sandy Soil Conditions

Abstract

Drought stress and nutrient status are highly important for plant growth and productivity. Two field experiments were conducted during two consecutive seasons (2017–2018 and 2018–2019) at El-Molak, Abo-Hammad, Sharkia, Egypt. This work was conducted under sandy soil conditions to evaluate the effects of foliar application with growth regulators (PGRs) such as cycocel (CCC), applied at 0, 500, or 1000 mg L−1, and/or salicylic acid (SA), applied at 0, 0.05, or 0.1 mM on the productivity as well as improving drought tolerance of three wheat cultivars, i.e., Gemmeiza 11, Misr 1, and Giza 171 under three irrigation intervals, i.e., 10, 15, and 20 days. Foliar spray was given at 35 and 50 days after planting (DAP). The obtained results showed that mean squares as a result of the main effect and first- and second-order interactions were significant (p ≤ 0.01) for all studied traits. The application of SA increased total chlorophyll content and flag leaf area (cm2) while the number of days to 50% heading was decreased; however, the number of spikes m−2, protein and proline contents were increased with the application of CCC. The cultivar Misr 1 outperformed the other cultivars in the most studied traits. Estimates of heritability in the broad sense (h2b) were, on average, higher in five physiological traits than other agronomic traits, and the highest estimate of h2b (95.1%) was shown by the number of days to 50% heading followed by protein content (91.90%). Among the interactions between irrigation and growth regulators, the I(10) × SA(0.1) recorded the highest flag leaf area (cm2), SPAD value, number of grains spike−1, 1000-grain weight (g), and grain yield (t ha−1). Among the interactions between irrigation and cultivars, the I(10) × Misr 1 recorded the highest flag leaf area (cm2), SPAD value, number of grains spike−1, and grain yield (t ha−1). Among the interactions among irrigation, growth regulators and cultivars, the I(10) × SA(0.1) × Misr 1 recorded the highest flag leaf area (cm2), number of grains spike−1, 1000-grain weight (g), and grain yield (t ha−1). Correlation coefficient between grain yield (t ha−1) and each of the number of days to 50% heading, flag leaf area, total chlorophyll content, number of spikes m−2, number of grains spike−1, and 1000-grain weight was positive and significant. Three main factors for the studied variables were created from the application of the factor analysis technique. Grain yield ha−1 (Y) can be predicted by the method of forwarding stepwise through applying the automatic linear regression analysis. Besides, the best prediction equation of grain yield ha−1 (Y) was formulated as: Ỷ = −14.36 + 0.11 number of grains spike−1 (NGS) + 0.09 1000-grain weight (THW) + 0.04 number of spike m−2 (NSm) + 0.03 days to 50% heading (DF) + 0.02 total chlorophyll content (TC) with adjusted-R2 (87.33%).

Application of Silica Nanoparticles in Combination with Two Bacterial Strains Improves the Growth, Antioxidant Capacity and Production of Barley Irrigated with Saline Water in Salt-Affected Soil

“…Moreover, the application of PGPR increased the excretion of indole acetic acid (IAA) and bacterial exopolysaccharide from soil microbes, which is one of the main steps in the improvement of soil properties. by reducing the concentration of Na + , which antagonistically increases the phytoavailability of other nutrients, mainly K + , Ca 2+ , and Mg 2+ [ 31 ]. The application of PGPR, directly and indirectly, boosts the growth and development of plants growing under salinity stress conditions.…”

Comparative Analysis of Plant Growth-Promoting Rhizobacteria (PGPR) and Chemical Fertilizers on Quantitative and Qualitative Characteristics of Rainfed Wheat

“…The potassium concentration of flag leaf and seed samples was determined according to Yoshida et al [20] using a flame photometer. The protein content of seeds was estimated after determining the concentration of nitrogen in the seeds and applying a coefficient of 6.25 [21].…”

Effect of Irrigation Intervals and Foliar Spray with Salicylic Acid on the production of Two Bread wheat cultivars in Newly Reclaimed Land

“…Many researchers reported that shorter irrigation intervals improved the growth and yield traits of wheat crops (Shah et al, 2016;Ragheb et al, 2017;Ahmed and Mustafa, 2018;Walsh et al, 2020;Munsif et al, 2022). Increasing irrigation period was followed by a significant decrease in all studied traits except for protein under sandy soils conditions, which leads to rapid loss of water and nutrients, and exposes plants to drought stress, thus an increase in protein content of wheat plants (El-Saadony et al, 2021). Moreover, Awad et al (2015) illustrated that drought stress led to number of grains spike -1 by 28.58 and 28.74%, grain weight plant -1 by 17.97 and 39.60%, 1000-grain weight by 36.97 and 7.95%, and grain yield by 35.56 and 39.38%, in comparison to full irrigation treatment in both seasons, respectively.…”