Ten yellow maize inbred lines were derived from different sources were evaluated in this study to estimate combining ability, type of gene action and superiority % of the F1 , s over commercial check hybrids. In 2019 grown season, all possible combinations between these lines were done in a half diallel (Griffing's 1956, method 4, model 1) to give 45 crosses at Sids Agricultural Research Station. In 2020 season, 45 crosses along two commercial hybrids; SC. 168 and SC. 3444 were evaluated in replicated trails conducted at three locations; Sakha, Sids and Nubaria Agricultural Research Stations. Data were recorded for days to 50% silking, plant height, ear height, ear position%, late wilt resistant % and grain yield. The results showed significant differences between the three locations for all the studied traits except LWR % and GY traits, indicating that the three locations differed in the environmental conditions. Mean squares of genotypes and their interactions with locations were significant or highly significant for all the studied traits. The results showed that the general combining ability and specific combining ability variances were significant or highly significant for all the studied traits, indicating that both additive and non-additive gene action were important in the inheritance of these traits. The parental lines Sd. 3180 and Sd. 21 had a good GCA effects for all the studied traits. The crosses Sk. 1 x Sd. 15 and Gm. 6052 x Gz. 658 showed desirable values of SCA effects and superiority% over check for yield.

Background Spodoptera littoralis is mostly controlled by the use of synthetic insecticides. Nonetheless, the use of these insecticides causes a slew of issues. On this pest, the antifeedant activity of Melaleuca alternifolia essential oil (EO) and its two principal components was investigated. Results The gas chromatography–mass spectrometry (GC/MS) analysis revealed that the M. alternifolia EO was composed of eleven compounds. Terpinen-4-ol (40.1%) and γ-terpinene (21.9%) were chosen as the major constituents. In terms of antifeedant efficacy, treatment with M. alternifolia EO and these components reduced leaf consumption and the efficiency of food conversion in larvae in a concentration-dependent manner. When compared to untreated larvae, weight, growth, and pupation percentage were all significantly lower. Conclusions The findings show that M. alternifolia EO and its components, terpinen-4-ol and γ-terpinene can be effectively combined for cotton leafworm management.

Article History

The 6 adjuvants when tested alone revealed remarkable toxicity against the tested aphids particularly Egyptol which exhibited the highest efficacy in this respect. However, Nestapon, Span 20 and Hamadol OD/600 came closely in rank while Especrin and Tween 20 were of little effect in this concern. Combinations of diflubenzuron and adjuvants at the rates evaluated revealed in general effectiveness against the cabbage aphids varied between synergism, independent and antagonism. Only combinations of diflubenzuron/Especrin showed significantly the highest synergistic action whereas other combinations of IGR/adjuvants such as Nestapon and Tween 20 exhibited highly pronounced antagonism. Zusammenfassung Über den Einfluß verschiedener Förderungssubstanzen (Adjuvants) auf die Wirkung von Diflubenzuron gegen die Kohlblattlaus Brevicoryne brassicae (L.) Die isolierte Anwendung von 6 getesteten Adjuvants hatte bei den Blattläusen bereits einen beachtlichen Vergiftungseffekt, wobei Egyptol am stärksten wirkte. Ihm nahe kamen Nestapon, Span 20 und Hamadol OD/600, während Especrin und Tween 20 nur geringen Einfluß ausübten. Bei Kombinationen von Adjuvants plus Diflubenzuron kam es zu Wirkungen, die zwischen Synergismus, Unabhängigkeit und Antagonismus variierten. Einen signifikant hohen Synergismus zeigte nur die Kombination von Diflubenzuron und Especrin, während andere Kombinationen wie Diflubenzuron mit Nestapon oder Tween 20 eine erhebliche antagonistische Wirkung erkennen ließen.