The objectives of the study were to investigate the genetic behavior of some biological and economical traits of 14 okra populations collected from Dakahlia Governorate, which underwent two cycles of inbreeding with selection. Selection of individual plants based on earliness, high number of pods, and minimum neck/pod ratio was carried out in all generations. The results showed that the means and ranges of all studied traits for all families became smaller in the S2 generation than those in the S0 generation. Highly significant variations were observed among populations for all the studied traits. The mean performance clearly indicated the agronomic superiority of some families over the others. Family 9 followed by family 12 showed the earliest flowering plants and the highest yield per plant. Phenotypic variances were higher than the corresponding genotypic variances indicating predominance of environmental effects on the expression of these characters. The magnitude of phenotypic and genotypic coefficients of variation varied from one trait to another. High broad-sense heritability coupled with high genetic advance as percent of mean were shown by the different traits, especially, plant height, number of branches per plant, number of pods per plant, pod length, neck/pod ratio and plant yield. This implicates that these traits were under the control of additive genetic effects, and could be effectively improved through selection. Plant yield had positive and highly significant correlation at genotypic and phenotypic level with number of pods per plant, plant height and neck/pod ratio.

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Two field trials were carried out during two consecutive winter seasons of 2009/10 and 2010/2011 at Baramon Experimental Farm, Dakahlia Governorate to investigate the effect of three planting dates (1 st Nov., 15 th Nov. and 1 st Dec.) and three plant spacing (50, 60 and 70 cm) on cabbage cv. Brunswick. The trials were laid out in a split-plot design with three replicates. Results indicated that the earliest planting date (1 st of November) significantly promoted vegetative growth characters, i.e. plant weight, number and weight of outer leaves. Moreover, the earliest planting date increased average head weight, total and marketable yield. Head quality attributes, i.e. head equatorial and polar diameters, head volume, head density and dry matter content were increased when planting at the earliest planting date, compared to the later planting dates. The wider plant spacing (70 cm within row) exhibited the largest values of plant weight, number and weight of outer leaves. The wider plant spacing produced heads with larger dimensions, volume and density. Otherwise, the closer plant spacing (50 cm within row) produced larger total and marketable yield in relation to that yield produced by wider spacing. The interaction effects among the experimental factors were significant at both seasons of this investigation for plant weight, total yield and dry matter content, whereas no significant interaction was found for other studied characters.

The aim of this study is to evaluate a set of inbred lines and their hybrids and to determinate the phenotypic and genotypic parameters. In addition, identify the heterosis and combining ability for the studied traits in order to determine the best combinations and the ideal improvement strategy for hybrid production in squash. The experimental study was conducted at El-Baramoon Research Station, Horticulture Research Institute during the two summer season of 2016 and 2017. Six inbred lines selected from Eskandrani cultivar and fifteen F 1 hybrids were evaluated for different traits. Significant differences were observed among the hybrids and their parents for all studied traits. Based on mid-parent heterosis, the hybrid (P 5 x P 6) gave the highest value for early yield per plant (98.51 %) followed by the hybrid (P 1 x P 4) (90.24%) for the same trait. While heterosis over better parent, the hybrid (P 1 x P 6) gave the highest value for early yield per plant (78.95 %) followed by the hybrid (P 5 x P 6) (73.91 %) for the same trait. Furthermore, the highest mid-parent hertrosis for total yield per plant was obtained by the hybrid P 4 x P 6 (75.0%) followed by P 5 x P 6 (60.38%) and P 4 x P 5 (59.65%). Otherwise, the largest heterosis over better parent for total yield per plant were expressed by P 4 x P 6 (61.77%) followed by P 4 x P 5 (46.77%) and P 5 x P 6 (37.10%), respectively. General combining ability (GCA) was significant or highly significant for all traits except for early yield per plant and shape index, specific combining ability was highly significant for all traits except for number of node female flower and early yield per plant. The estimated GCA/SCA mean squares revealed that the additive gene effects were the major effect in the inheritance of all studied traits, except for early yield per plant and vitamin C. Also, GCA estimates were larger than their corresponding estimates of SCA for most of the studied traits. The result illustrated that both additive and non-additive gene actions were positive for all studied traits. Heritability in broad sense ranged from 72.95 to 99.46 % for number of node female flower and total soluble solids, respectively. Also, heritability in narrow sense ranged from 28.49 to 81.94 % for number of leaves per plant and fruit shape index. The parent P 1 , P 2 and P 3 could be recommended as good combiners for average fruit weight, vitamin C, number of fruits per plant and total yield per plant whereas the P 5 and P 6 as promising parents for plant height, leaf area, number of leaves per plant , days to anthesis of female flowers, number of node of female flower and total soluble solids.

Due to the increased water shortage and frequent drought in Egypt, it is essential to develop droughttolerant plants. Therefore, five drought tolerance lines of okra were used to develop superior hybrids under drought conditions, using a half-diallel mating design to produce fifteen hybrids. There were significant differences among the hybrids and their parents in mean squares for all studied traits. The hybrids (P 2 XP 6 ), (P 2 XP 3 ), (P 1 XP 2 ) and (P 2 XP 4 ) exhibited the maximum mid-parents (MP) and better parent (BP) heterosis for total yield/plant.The mean squares for general (GCA) and specific combining abilities (SCA) were significant for studied traits, which indicates the importance of additive and non-additive gene actions in the inheritance of the studied traits in okra.The magnitudes of additive genetic variance (σ 2 A) were larger than their corresponding non-additive genetic variance (σ 2 D) for plant height, number of branches per plant, number of days to 50% flowering, pod length and total yield/plant. This revealed the major effect of additive inheritance for these traits.Genetic analysis illustrated that broad sense heritability (h 2 bs %) values were larger than their corresponding heritability in narrow sense(h 2 ns %) for all studied characters.As for the correlations between yield component traits, there were significant and positive genotypic correlation (r g ) among total yield/plant and plant height, average pod weight and number of pods/plant. Overall, these crosses are promising hybrids with high yielding ability, and could be commercially recommended to improve economical traits in okra under drought conditions.