A crude acetone extract and oil of ripe fruits from Melia azedarach L. were evaluated against the 2 nd and 4 th instar larvae of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae). Both oil and extract exhibited highly signifi cant growth inhibition at all concentrations tested, while the oil of M. azedarach recorded higher insecticidal activity against both instars than the crude extract. GC-MS analysis of the oil revealed the presence of linoleic acid methyl ester, oleic acid methyl ester, and free oleic acid as the main components in addition to hexadecanol, palmitic acid, methyl esters of stearic acid and myristic acid. Fatty acids and their esters were not only the main constituents of essential oil from the ripe fruits of M. azedarach, but also mainly responsible for the insecticidal and growth inhibition activity against S. littoralis.

Powdery mildew disease, caused by Erysiphe cichoracearum, is considered one of the most severe pathogenic threats of sunflower worldwide. This study discusses how to improve the effect of biocontrol agents, as a more economic and ecofriendlier alternative to fungicides, by mixing different bioagents (Trichoderma harzianum and Bacillus subtilis) with different antioxidants (ascorbic acid and salicylic acid), either individually or combined. They were applied to sunflower during two successive seasons to determine their effectiveness in promoting growth and inducing resistance in sunflower against powdery mildew disease under field conditions. Results show that all treatments reduced the severity of powdery mildew disease significantly compared with control. A synergistic effect was noticed when combining T. harzianum and salicylic acid led to a significant decrease in powdery mildew disease severity in sunflower in comparison to control. In general, the results suggested that the integration of antioxidants with bioagents showed a better response to control powdery mildew disease than single treatments. Applied treatments in the field significantly increased all of the studied growth parameters, plant length, fresh and dry weight. All treatments showed a remarkable increase in physiological aspects (enzymes activity and total phenol content).

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Toxicity and reduction in larval body weight studies were performed to determine the activity of linoleic acid against the 2 nd and 4 th instar larvae of Spodoptera littoralis. The tested fatty acid showed high significant toxic effect on the two instars, with LC 50 values of 4.78 and 9.11 g/100 mL, respectively. Linoleic acid resulted in significant larval weight reduction. The percentage of larval body weight reduction against the 4 th instar was higher than that of the 2 nd instar larvae.

Herein, we declare on the biosynthesis of synthesised silver nanoparticles utilizing the aqueous extract of Origanum Marjorana by reducing 1 mM silver nitrate at room temperature. AgNPs were characterized by using some common techniques such as an ultra violet spectrophotometer, Fourier transforms infrared spectroscopy, X-ray diffraction, and transmission electron microscopy. Morphologically, AgNPs demonstrated a spherical shape with an average particle size distribution of 63-85 nm. FT-IR studies showed the presence of bioactive useful bunches such as phenolic compounds, amines, and aromatic rings are found to be the capping, stabilizing specialists and required for the reduction of silver ions of AgNPs. The measurement of toxicity of AgNPs and the plant extract of O. marjorana against Earias insulana was also discussed. After the treatment of synthesized nanoparticles for two successive seasons, general reduction percentages on the infestation of the green boll caused by E. insulana larvae in the second season was more by 60.4% than the first season which was 44.73%. Synthesized AgNPs treatment was considered more effective than plant extract for controlling E. insulana. General reduction percentages in the infestation of the green boll caused by E. insulana larvae in the first season associated with the treatments with AgNPs and plant extract were 44.73 and 37.53% while the second season record 60.4 and 51.82%; respectively.