Maize is considered one of the most imperative cereal crops worldwide. In this work, high throughput silica nanoparticles (SiO₂-NPs) were prepared via the sol–gel technique. SiO₂-NPs were attained in a powder form followed by full analysis using the advanced tools (UV-vis, HR-TEM, SEM, XRD and zeta potential). To this end, SiO₂-NPs were applied as both nanofertilizer and pesticide against four common pests that infect the stored maize and cause severe damage to crops. As for nanofertilizers, the response of maize hybrid to mineral NPK, “Nitrogen (N), Phosphorus (P), and Potassium (K)” (0% = untreated, 50% of recommended dose and 100%), with different combinations of SiO₂-NPs; (0, 2.5, 5, 10 g/kg soil) was evaluated. Afterward, post-harvest, grains were stored and fumigated with different concentrations of SiO₂-NPs (0.0031, 0.0063. 0.25, 0.5, 1.0, 2.0, 2.5, 5, 10 g/kg) in order to identify LC₅₀ and mortality % of four common insects, namely Sitophilus oryzae, Rhizopertha dominica, Tribolium castaneum, and Orizaephilus surinamenisis. The results revealed that, using the recommended dose of 100%, mineral NPK showed the greatest mean values of plant height, chlorophyll content, yield, its components, and protein (%). By feeding the soil with SiO₂-NPs up to 10 g/kg, the best growth and yield enhancement of maize crop is noticed. Mineral NPK interacted with SiO₂-NPs, whereas the application of mineral NPK at the rate of 50% with 10 g/kg SiO₂-NPs, increased the highest mean values of agronomic characters. Therefore, SiO₂-NPs can be applied as a growth promoter, and in the meantime, as strong unconventional pesticides for crops during storage, with a very small and safe dose.

In Egypt, water shortage has become a key limiting factor for agriculture. Water-deficit stress causes different morphological, physiological, and biochemical impacts on plants. Two field experiments were carried out at Etay El-Baroud Station, El-Beheira Governorate, Agriculture Research Center (ARC), Egypt, to evaluate the effect of potassium silicate (K-silicate) of maize productivity and water use efficiency (WUE). A split-plot system in the four replications was used under three irrigation intervals during the 2017 and 2018 seasons. Whereas 10, 15, and 20 days irrigation intervals were allocated in main plots, while the three foliar application treatments of K-silicate (one spray at 40 days after sowing; two sprays at 40 and 60 days; and three sprays at 40, 60, and 80 days, and a control (water spray) were distributed in the subplots. All the treatments were distributed in 4 replicates. The results indicated that irrigation every 15 days gave the highest yield in both components and quality. The highly significant of (WUE) under irrigation every 20 days. Foliar spraying of K-silicate three times resulted in the highest yield. Even under water-deficit stress, irrigation every fifteen days combined with foliar application of K-silicate three times achieved the highest values of grain yield and its components. These results show that K-silicate treatment can increase WUE and produce high grain yield requiring less irrigation.

Worldwide, maize (Zea maysL.) is considered an important food and fodder crop. Compost as a soil amendment and potassium (K) could enhance the maize yield. Therefore, two field experiments were carried out in the two seasons 2017 and 2018 to study the effects of compost at three levels and four forms of potassium fertilization on the yellow maize hybrid ‘PioneerSC30N11’ yield components. To conduct the field trials, a split plot system in three replications was established. Three compost levels (0, 5 and 10 ton/ha) were in the main plots, and four potassium forms (untreated, nano-potassium fertilizer, humic acid and potassium sulfate) were in the subplots. Plot size was 10.50 m², with 5 ridges with 3 m length and 0.7 m width. The results indicated that the application of compost (as organic manure) and the potassium forms significantly affected the plant height, ear length, grains number/rows, grains number/ear, 100- grain weight, straw and biological yields, grain protein and K contents in both seasons. Increasing the compost from 5 to 10 ton/ha increased the yield, its components, protein and K contents. The foliar application of nano-potassium followed by humic acid increased all the studied characteristics. The interaction between compost manure (10 ton/ha) and nano-potassium (500 cm³/ha) or humic acid (10 ton/ha) recorded the highest mean values for all parameters during both harvest seasons.

Abiotic stresses are the most major limitation to crop production, causing yield losses up to 50%, and consider the major challenges for production of crops. Thus, an experiment was conducted to determine how sugar beet would respond to soil application of K-humate rates and foliar application of biostimulants under salt stress. Split-plot design in three replicates was used in both seasons, where K-humate rates fertigation (control, 12, and 24 kg ha⁻¹) allocated in the main plots, and different foliar application of BS arranged within the subplot (i.e., (1) water spray, (2) salicylic acid (SA) at the rate of 100 mg L⁻¹, (3) fulvic acid (FA) at the rate of 1.2 kg ha⁻¹, (4) hydroxyproline (HP) 1000 mg L⁻¹, (5) SA at 100 mg L⁻¹ + FA at 1.2 kg ha⁻¹, (6) SA at 100 mg/L + HP at 1000 mg L⁻¹, (7) FA at 1.2 kg ha⁻¹ + HP at 1000 mg L⁻¹, (8) SA 100 mg L⁻¹ + FA 1.2 kg ha⁻¹ + HP 1000 mg L⁻¹) in the two seasons. The finding results revealed that soil application of K-humate, foliar application of BS, and their interaction significantly affected yield, growth, and quality characteristics of sugar beet under soil salinity, furthermore with soil application of K-humate at the rate of 24 kg ha⁻¹ with foliar spray of FA + HP recorded the highest of growth traits, top, root, sucrose %, sugar yields/ha⁻¹ and the lowest values of Na content in the juice and quality of sugar beet under the study conditions, Alexandria, Egypt.

The current study aimed to investigate biofortification of maize grown under different irrigation intervals, i.e. 15, 20 and 25 days (hereinafter referred to as IR15, IR20 and IR25, respectively), using foliar application treatments (silicon (Si), zinc (Zn), silver nanoparticles (AgNPs), Si + Zn, Si + AgNPs, Zn + AgNPs and Si + Zn + AgNPs) in two growing seasons, 2020 and 2021. A split-plot design with four replications was used, where irrigation intervals and foliar treatments were assigned in main plots and subplots, respectively. IR15 received a total of 7925 m³/ha irrigation water divided over seven irrigations, while IR20 received 5690 m³/ha divided over five irrigations and IR25 received 4564 m³/ha divided over four irrigations. The highest yield and grain quality were observed in plants irrigated at 15-day intervals. Spraying the canopy with Si, Zn and AgNPs, either individually or in combination, reduced the negative impact of water stress caused by longer irrigation intervals on plant growth, yield, yield components and grain protein content. In IR15 + AgNPs + Zn, most of the studied parameters, except for proline content, showed a high positive impact, especially on 100-kernel weight (KW). In contrast, IR25 + Si + AgNPs + Zn showed the highest positive effects on proline and protein contents but a negative impact on the harvest index. Collectively, IR15 + Si + AgNPs + Zn resulted in the highest values of all studied parameters, followed by IR15 + Si + AgNPs and IR15 + Si + Zn. In conclusion, our results suggest that an irrigation interval of 15 days combined with application of Si, Zn and AgNPs has the potential to improve yield and quality of maize under water deficit stress.