No abstract

The toxicity of benzothiazole derivatives obtained from 2-cyanomethyl benzothiazole against cotton leafworm Spodoptera littoralis 2nd and 4th instar larvae has been documented. The main objective of this research was to formulate two previously reported chromen derivatives and test their biological activity against cotton leafworm S. littoralis 2nd and 4th instar larvae under laboratory conditions. According to the standard method, two chromen derivatives with two distinct substituents (salicylaldehyde and 2-hydroxy-1-naphthaldehyde) were synthesized. Their physical and chemical properties were evaluated, and both were formulated as 10 and 9.5 percent dustable powder formulations. Both formulae were then evaluated in the laboratory on cotton leafworm S. littoralis 2nd and 4th instar larvae for mortality and developmental effect percentage. Formulation (F2) was more efficient than formulation (F3) in both cases and for both stages. Furthermore, when comparing the developmental effects on the 2nd and 4th instar larvae, the 4th instar larvae demonstrated marked tolerance. Both stages were unable to complete their life cycle. Histopathological analysis of samples from the affected stages was performed to assess the mode of action of these formulations on 4th instar larvae at their LC50 values. Experimental data showed that Formulation (F3) resulted in epidermal cells separated from the cuticular layer, necrosis, ruptured columnar cells with pyknotic nuclei, disrupted basement membrane, and weak epicuticle necrosis and separation. In comparison, formulation (F2) revealed a midgut with vacuoles, damaged columnar, muscle cell necrosis, and a ruined peritrophic matrix. Thus, the cotton leafworm S. littoralis could be combated with the newly prepared formulations (F2) and (F3).

Sakha107 was released in 2016 as a high yielding cultivar, good grain quality and short stature with earliness under water shortage in Egypt. Sakha107 was developed from single crossing between Giza 177 and BL1. The cross had initiated in 2000, as F1 then was forward to F2-F5 segregating populations and advanced up to 2006 to reach stability, uniformity and homozygosis up to F6. The promising line GZ8710-3-2-1-1 exceeded all selected lines and was evaluated from 2007 to 2016 in multi-location yield trials, regional, final, verification, DUS, VCU experiments and demonstration yield trials. Sakha 107 cultivar have good agronomical traits i.e., good root system, seedling vigor, tillering ability, short stature, earliness duration 123 day, erect leaves, high leaf area index, high reproductive tillers, large panicles, short grain shape, high grain yield 9.45 and 6.5 t ha -1 under both normal and drought conditions ,respectively and straw yield with high harvest index 42.0 % as well as milling, chemicals, cooking characteristics, and resistance to the major diseases such as blast, brown spot, false smut, white tip nematode and Bakanae, in addition to high genetic potential for productivity where the productivity in the demonstration field was 4.3 t/fed and 3.7 t/fed for adjacent field in different governorates during the periods 2017 to 2019 seasons . It is an outstanding new cultivar to released and recommended for cultivation in the various rice-producing regions, mainly in areas that are exposed to declining water irrigation and resources in Egypt.