الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
SUMMARY AND CONCLUSION
Cotton in Egypt ranked first in relation to fiber crops and efforts are exerted to
increase cotton production and quality through agricultural policies and breeding new
varieties.
It is well known that the productivity of any variety is the outcome of the
interaction between the genetical constitution and environmental conditions. For this
reason, cotton should be grown under suitable environmental conditions to achieve
the highest yield and the best quality.
Therefore, 30 field experiments were conducted during the three successive
seasons 1992 , 1993 and 1994 at ten different regions :-
- Upper Egypt (Sohag, Assuit, El-Minia and EI-Faiyum).
- Southern and Middle Delta (Dakahlia, EI-Gharbia and sharkeih.
- Northern Delta (Kafer El-Sheikh, El-Beheira and Damaitta), to evaluate 15
cotton genotypes of which twelve are the commercial varieties namely, dendera, Giza
45, Giza70, Giza 75, Giza76, Giza 77, Giza 80”Giza 81, Giza 83, Giza 84, Giza 85
and Giza 86, in addition to the three promising strains (Giza 75 x Rus. 6022), (Giza
77 x Giza 45A ) and (Giza 77 x Giza 45B) .
Varieties and strains all together were grown following the routine adapted in the
experimental stations. A complete randomized blocks design with four replications in
each of the 30 environments (combination of ten locations in three years).
Variance components and different stability estimates over location and years were
calculated for seed cotton yield and yield components, in addition to fiber property
traits.
The resuhs obtained could be summarized as follows :-
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I .1. Effect of cotton variety :-
I • 1. A • Varietal effect on the yield and yield components :-
Results obtained revealed that yield and yield component characters were
highly significantlyaffected by cotton variety.
1- Mean seed and lint cotton yields showed that Giza 85 and the promising strain
Giza 75 x Rus. 6022 had the highest values, while Giza 45 gave the lowest
yields.
2- Regarding boll weight and seed index, Giza 75 and Giza 85 gave the highest
values for these traits, while Giza 80 and Giza 83 had the highest values for lint
percentage and lint index. On the other hand, Giza 45 and the promising strain
Giza 77 x Giza 45A had the lowest values for lint percentage and lint index.
L 1. B. Varietal effect on the fiber properties :-
The results demonstrated that all the studied fiber properties were significantly
affected by variety .
Mean values of the micronaire reading were lowest for Giza 45 and Giza 77 x
Giza 45A.
As for fiber strength and fiber length, it was clear that Giza 70, Giza 45 and
Giza 77 x Giza 45B had the highest values.
L 2 • Effect of the years :-
L 2 : A Seasonal effect on the yield and yield components :-
Results revealed that the climatic conditions during the second year (1993)
affected favorably all characters under study in comparison with the other two
years of 1992 and 1993. The differences among the three years were
significant for all characters, except number of bolls per plant and lint
percentage .
L 2. B. Seasonal effect on the fiber properties :-
Results revealed that the climatic conditions during the second year (1993)
were more favomable than those in the other two years (1992 and 1994) in
affecting the two characters micronaire reading and 50 %span length only.
The differences were significant among the three years in all characters, except
fiber strength trait.
L3. Effect of the location :-
I .J. • A • location effect on the yield and yield components :-
The ten locations differed significantly concerning seed cotton yield, lint yield
and lint percentage. EI-Faiyum governorate favourably affected seed cotton
yield, lint yield, boll weight, number of bolls per plant and seed index as
compared with the other locations. While, El-Beheira was better than EIFaiyum
for lint index trait. El-Dakahlia governorate favourably affected lint
percentage. On the other hand, El-Minia and Assuit governorates were lower
than other locations tested in all characters studied.
I • 3, • B • location effect on the fiber properties :-
The ten location differed significantly concerning fiber properties, except the
micronaire reading. EI-Faiyum and Sohag governorates favourably affected
fiber strength and fiber length (2.5 % and 50 % span length) and recorded the
highest values as compared with the other locations, while the lowest values
were observed in El-Mioia and Sharkeih locations.
L 4 • Effect of the interaction between cotton varieties and yean :-
Significant interaction effects were detected for seed and lint cotton yields,
number of boDs per plant, lint percentage, lint index, seed index and all fiber
property traits under study.
These results give evidence that the varieties differed in their responses to the
environmental conditions from one year to another.
This means that the superiority of a certain variety depends on the conditions
prevailing dwing the growing season.
I • 5 • Effect of the interaction between cotton varieties and locations r-
Significant effects for genotype x location were found except, with boll weight
and lint index which were not significantly affected with this interaction.
1. from the resuhs of seed and lint cotton yields, it is apparent that for producing
the highest seed and lint cotton yields, it is recommendable to grow Gina 80
variety at Upper Egypt (Sohag and Assuit), Gina 85 and Gina 83 at Middle
Egypt (El-Minia and El-Faiyum), the promising strain Giza 75 x Rus. 6022 at
South and Middle Delta (El-Gharbia and EI-Sharkeih) and to grow Giza 83,
Gina 86 and Giza 75 x Rus. 6022 genotypes to get the highest yield at North
Deha (Dakahlia, Damiatta, EI-Beheira and Kafer EI-Sheikh).
2. High mean seed cotton yield and yield components exhibited by the long staple
genotypes are due to their genetic constitution in addition to their high
adaptability for wide environmental conditions at several locations and it could
be recommended that they are to be included in the breeding programs aiming
to improve yield and its components. On the other hand, the extra-long staple
genotypes were less adapted for wide environmental conditions thus, these
genotypes have to be grown in the North Delta regions as the environment
conditions are more suitable for producing the best fiber properties, because
Extra-long staple genotypes produce higher fiber strength and longest fiber
length than the long-staple ones, mainly due to genetic differences between
them
I • 6. Effect of the interaction between locations and years :_
This interaction had highly significant effect on all yield and its components
and fiber properties traits under study.
from the resuhs of the interaction between location and years, it could be seen
that the different traits changed in these means from location to another and
from year to another, but generally it can be seen that Sobag in 1992 was the
best environment for fiber properties, while EI-Faiyum at the same year gave
the best yield.
I • 7 • Effect of the interaction between cotton varieties. locations and years:-
This second order interaction affected significantly all traits of yield and its
components. The effect was highly significant for all fiber property traits
except, fiber length (2.5 % and 50 % span length), which were insignificantly
affected.
The results show the important role of each of (genotypes, locations, years,
locations x years interaction, as well as genotypes x environment interaction)
that affect seed cotton yield and yield components and also fiber property
traits ..
Therefore, it seems necessary to continue evaluating cotton genotypes, old or
newly produced, by growing them at several locations over an adequate
number of years before recommending any variety for a certain location.
n.Varian” component’ and beritabjlilv :_
I . High heritability values were reached for seed cotton and lint cotton yields,
being 89.55 % and 94.05 %, respectively.
2 High heritability values of95.71 %.85.58 %. 99.22 %.99.06 % and 93.92 %
were also reached for boll weight, number of bolls per plant, lint percentage,
lint index and seed index traits, respectively.
3 There was an essential amount of genetic variance for each trait hence, the
broad sense heritabilty estimates were high for all traits. Genetic coefficient of
variability ranged from 4.37 % for seed index to 17.28 % for lint yield, these
values indicated the environmental effects on all traits studied.
4 The high heritability values for fiber properties were 97.89 %. 97.82 %,
99.26 %and 97.84 %for micronaire reading, fiber strength, 2.5 % span length
and 50 % span length, respectively.
5 . Genetic coefficient of variability ranged from 5.24 % (for 50 % span length) to
8.92 % (for micronaire reading). These values indicated that environment
effects on all traits studied were considerable.
m • r...enptynje; ’tahUin for djffercut &CU0types :-
1. Adaptability estimates indicated that Giza 45, Giza 76, Giza 70, Giza 77 and
Giza 77 x Giza 45A which yielded below average mean yield over
environments are poorly adapted to all environments. However, the genotypes
Giza 75 x Rus. 6022, Giza 85, Giza 83, Giza 86, Giza 75, Giza 84 and Giza 80
which were above average mean yielding ability had general adaptability or
well adapted to all environments. The remaining genotypes (Dendera, Giza 81
and the promising strain Giza 77 x Giza 45B) which were not significantly
different from the average mean performance of all cultivars had average
stability.
2 - The several stability estimates used, indicated that for selection for stability with
the objective of incorporating this important trait in the Egyptian cotton
germplasm, the following genotypes may be considered as breeding stocks for
specific traits :-
Seed cotton yield
Lint cotton yield
Boll weight and seed index
Number of opening bolls per plant
Lint percentage
Lint index
Giza 75 x Rus. 6022.
Giza 84.
Giza 80 and Giza 86.
Giza 86.
Giza 86 , Giza 81 , Giza 77.
and Giza 77 x Giza 45B.
Giza 86 and Giza 85.
3- Only extra-long staple met the performance response and stability characteristics
of ideal genotypes for all fiber property measurements. Therefore, the extralong
staple genotypes may be used as a breeding stock for incorporating in any
crosses with the objective for selection for stable :fiber properties (micronaire
reading, :fiber strength and :fiber length).