THE PRESENT work was conducted to study the effects of late planting on the performance of Egyptian cottons, sensitivity to environments and gene action controlled earliness, lint yield/plant, lint % and lint index. A half diallel crosses of eight Egyptian cottons varieties were evaluated under normal and late plantings. The reduction % in lint yield/plant was 23.21 and 23.87% for the parents and F1 hybrids; respectively. The results of stress susceptibility index of LY/P indicated that six parents were tolerant for LY/P to late planting. Sixteen out of the 28 hybrids showed tolerance in LY/P to late planting. The diallel analysis revealed significant (p ≤ 0.01) items; ‘’a’’ and ‘’b’’, indicating that both additive and dominance effects of genes were involved in the inheritance of the five studied traits. The genetic parameter indicating that ‘’H1’’ tended to be more than the additive parameter ‘’D’’ under late planting. The regression analysis of Wr/Vr indicated the presence of non-allelic interaction in the inheritance of lint yield/plant under late planting. However, the additive–dominance model was adequate in the inheritance of days to first flower under normal and late plantings. The ‘’b2’’’ item and KD/KR indicated unequal distribution of dominance and recessive genes in the parents for all traits. The non-additive effects of genes were reflected in the departure of narrow form broad sense heritability. Therefore, pedigree and recurrent selection breeding methods could be effective to isolate lines adapted to late planting.

This study examined the relationships of some agronomic traits associated with achene yield and oil content in selected S1 per se families of Giza 102 sunflower cultivar. And to employ the cluster and principle component (PC) analyses to identify and classify superior S1 families based on the genetic distances. The current work was carried out at Shandaweel Agric. Res. St., ARC, Sohag, during two successive summer seasons, 2016 and 2017. 23 S1 per se families and Giza 102 were evaluated for days to 50% flowering (DF), days to maturity (DM), plant height (PH) in cm, stem diameter (SD) in cm, head diameter (HD), 100-seed weight (SI) in g, achene yield per plant (AY) in g plant-1, achene yield per plot (ACP) in g plot -1 and oil content (%). Achene yield/plot showed highest positive correlation coefficients with achene yield/plant followed by seed index, head diameter and stalk diameter at genotypic and phenotypic levels. Three main components (PC1, PC2 and PC3) have been extracted that accounted for 78.65 % of the variability. The portion of each three components was 38.09, 28.23 and 12.33% of total variance, respectively. Achene yield/plant and achene yield/plot have the highest weight in PC1 and S1 families can be grouped by utilizing these two components. Head diameter, SI and SD were associated positively with PC1. Days to flowering, DM and PH were correlated to PC2, while oil content was associated with PC3. The 23 S1 families and Giza 102 were clustered into mainly three clusters. Cluster I was characterized by the highest mean value for achene yield/plot, achene yield/plant, head diameter, stalk diameter and seed index. The research concluded that the S1 families i. e. 15, 9, 5, 18, 14, 22 and 23 could be selected for simultaneous improvement for yield and earliness in sunflower.

Additive main effects and multiplicative interactions (AMMI) model anal-yses were performed to assess and quantify the magnitude of genotype by envi-ronment interaction (GEI) for number of days to heading (DH) and grain yield (GY/P) stability of sixteen promising bread wheat (Triticum aestivum L.) geno-types. Field experiments under recommended (N) and late (L) sowing date in newly reclaimed soil were conducted in the Agricultural Research Station at Ar-ab-Elawamer, Assiut, Egypt for three consecutive seasons (2016/2017, 2017/2018 and 2018/2019). The combined ANOVA showed highly significant differences among genotypes and among environments for both traits, while GEI was highly significant for DH and not significant for GY/P. Results of AMMI analysis indicated that the first three AMMI (PC1, PC2 and PC3) were highly significant for DH and AMMI1 was only significant in case of GY/P. In addition, the environments showed high contributions to the total sum of squares (TSS) and explained 84.7 and 85.3% for days to heading and grain yield/plot, respec-tively. While, the genotypes captured 10.4 and 6.8% of the TSS for the same traits, respectively. Although that the GEI showed low contribution to the total SS, but its magnitude (7.9%) was larger than that for genotypes in case of GY/P. The AMMI stability value discriminated genotypes G3, G7, G9, G12 and G14. G3 were the most promising stable and adapted genotypes according to grain yield performance over environments.