الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
SUMMARY AND CONCLUSION
The present study was carried out in the summer seasons of 2003 and 2004 to investigate the deterioration in fiber quality characters of Giza 70 cotton variety that led to a decline in area allocated for its production until it was finally removed from production. Experiments were grown at Agricultural Research Station, Faculty of Agriculture, Alexandria University in Abbis. The experiments included eight populations of Giza 70 variety representing seed lots collected from several ginning mills. The obtained results may be Summarized in the following:
5.1. First season 2003:
The eight populations were grown in a randomized complete block design of four replications. The most important results obtained from this experiment were:
1- There was evidence of mechanical mixing of Giza 70 seeds, collected from the different mills, with seeds of other varieties.
2- Analysis of variance showed significant variations for number of fruiting branches and number of bolls/ plant, boll weight, seed cotton yield/ faddan and lint percentage.
3- Population D had the highest number of fruiting branches/ plant and was significantly higher than populations F, G and H.
4- Population F had the significantly highest number of bolls/ plant (12.62) while population H gave the significantly lowest value (9.56).
5- Population B had the heaviest boll weight (2.85 g) and was significantly superior to all other populations.
6- Populations F and B had the highest seed cotton yield/ plant (31.9 and 32.37 g), respectively.
7- Populations B and H had the highest lint percentage (35.25 %) while population F exhibited the lowest lint percent (32.25 %).
8- Analysis of variance showed significant and highly significant differences with regard to mean length, uniformity ratio, fiber strength and short fiber index.
9- Population C was significantly inferior to all other populations in mean length (27.64 mm), uniformity ratio (85.56 %) and short fibers index (6.83).
10- High coefficient of variations were recorded for fiber quality traits especially short fibers index.
5.2. Second season 2004:
Twenty lines resulting from selfed seeds, in each population, were grown in a split-plot design of four replications, where populations were assigned to the main plots and lines were allocated to the subplots. Results obtained from that season may be summarized as follows:
5.2.1. Plant vegetative characters:
1- Significant and highly significant variations were detected for number of days to first boll opening, number of vegetative branches/ plant, height of first reproductive node and number of lobes/ leaf.
2- Populations B, C, E and G were significantly later in first boll opening compared to populations D and H.