The present study was carried out to verify the variation of short fiber content (SFC) and its importance. The instruments and/ or methods used to measure short fiber include High Volume Instrument (HVI), Fibrograph 630 and Suter-Webb array. Materials used in this study included the extra-long and long staple varieties with wide range of lint grades. The three measures of short fiber especially, Suter-Webb-SFC exhibited high variations for lint grades and low variations for cotton varieties. Suter-Webb short fiber shows higher values than the HVI and Fibrogragh short fiber. Results indicate that most of the fiber and yarn quality properties are strongly correlated with each of the three measures of short fiber content. Comparisons between the three measures indicate that they correlate well with each other. Highly significant regression model was developed to predict short fiber content from maturity percentage, fiber length, length uniformity and fiber strength. The closer normalized short fiber content (NSF) is to 1 (or 100%), the higher the agreement between SFC and predicted short fiber content (PSF).

A promising cotton inbred line characterized by high yielding ability, earliness in maturity and better fiber quality was developed via pedigree selection from the subsequent segregating generations of a cross between the two long-staple cvs.; Giza 89 and Giza 86 by the Cotton Breeding Section of the Cotton Research Institute. The purpose of this investigation aimed at assessment of the superiority of the physical and fine structural properties of the promising line derived from the cross (Giza 89 x Giza 86) over its parents. The results indicated that: -  The promising line surpassed its parents in upper half mean length, uniformity index, fiber strength, fiber elongation, micronaire value, maturity ratio, hair weight, dry fiber ribbon width, swollen fiber diameter, convolution number / cm., reversals number/ cm. and yarn strength. - There were highly significant positive correlations between upper half mean length, uniformity index, convolution number/cm., fiber bundle strength and yarn strength. - Highly significant negative correlations exhisted between dry fiber ribbon width, swollen fiber diameter, reversals number and bundle strength.   The promising line is now under propagation for growing as a commercial cultivar and would replace both parents in their growing areas.

Two pot experiments were carried out at the greenhouse of the Cotton Research Institute, Agric. Res. Cent., Giza, Egypt during 2015 and 2016 seasons to study the response of cotton plant to application of some nutrients to improve the performance of cotton plant under irrigation of saline water to increase growth, yield and yield components and fiber quality of Giza 90 cotton cultivar.  The experimental design was a split plot design with four replications. Main plots included saline water solutions treatments (control, 2000, 4000, 6000 and 8000 ppm), sub plot included four nutrients application (Potassium Humate, Algex, Poly Ethylene Glycol (PEG) 6000 and Potassein compared with control). The obtained results could be summarized as follows: Irrigation with saline  water over seasons significantly decreased plant height, number of fruiting branches/plant, number of open bolls /plant, boll weight, seed index, seed cotton yield per plant, fiber length, uniformity index, fiber strength and micronaire value,  while, lint % was significantly increased. Nutrients application had significant effect on growth parameters, yield and its components and fiber properties under study, All nutrients treatments gave the highest values of growth parameters, yield and its components and fiber properties as compared with the control in both seasons. In general, plants sprayed with PEG gave the highest averages of plant height, number of fruiting branches/plant. Potassium Humate gave  the highest averages of yield and its components and fiber properties followed by plants sprayed with Algex, while the plants sprayed with PEG as came the last in these respect in both seasons. Interaction between irrigation with slain water and nutrients application by salinity tolerance inducers had a significant effect on plant height, number of fruiting branches per plant,  boll weight,  number of open bolls /plant, seed index, seed cotton yield /plant and fiber quality under study in both seasons. Plants treated with foliar nutrients under salinity condation scored the highest average of growth parameters, yield and its components and fiber properties. Potassium Humate, Algex, PEG and Potassein applications to plants under normal and salinity conditions had positive effects on improving the performance of cotton plants, which increased plant growth and yield especially under salinity conditions.

Two field experiments were conducted at Sakha Research Station, Cotton Research Institute, Agricultural Research Center at Giza, Egypt during the two summer growing seasons ,2014 and 2015 The aim of the work was to study the effect of the combination among nano-fertilization ,mineral fertilization and organic fertilization on growth, yield and fiber technological properties of Egyptian cotton Giza 94 cultivar.                 The most important results can be summarized as follows: Response of cotton yield and lint properties to mineral N.P.K nano-fertilization the complex treatment contains half dose of both the nano-fertilizer and the bio-organic fertilizer gave the highest reading for plant height (cm), number of fruiting branches per plant, number of open bolls per plant, boll weight (gram), lint percentage, Seed index, Seed cotton yield (Kentar/fed.) , Lint cotton yield  (Kentar/fed.), fiber maturity ratio (MR), upper half mean (UHM)mm, fiber uniformity index (UI), fiber strength  (g/tex), and micronaire value flowed by the treatment 100% nano then the recommended dose of mineral fertilizer NPK. On the other hand, the lowest values for all the above traits, were recorded from the half does of NPK mineral fertilizer in 2014 and 2015 seasons, .While, There were no significant differences between the means of the fiber elongation % due to the treatments applied during the study in 2014 season .It's worthy to mention that, the percentage of fiber elongation had no constant trend due to fertilizer transactions applied on the adopted genotype during` 2015 season, meaning that nano-fertilizer is boosting the fiber elongation percent.

The present investigation was carried out at the Experimental Farm of the Faculty of Agriculture at Fayoum, Cario University at Dalla, Fayoum Governorate during the two seasons 2000/2001 and 2001/2002. The aim of this investigation was to study the effect of organic manure and number of berseem cuts on cotton yield and its components and fiber traits. The obtained results indicate that only plant height at harvest, number of fruiting branches / plant and the height of the 1st fruiting branch were significantly affected by organic manure (O.M.) application. On the other hand, organic manure did not affect significantly the seed cotton yield, yield components and fiber quality traits. Cotton planting dates affected significantly all studied vegetative growth, seed cotton yield, yield components and fiber quality traits. Early planting date (1st week of March) showed significant superiority over the other two planting dates (1st week of April & May) in number of fruiting branches/ plant, number of days to 1st flower appearance and 1st boll opening, number and weight of open bolls/ plant in the 1st& 2nd pickings, seed cotton yield, lint percentages and studied fiber quality traits. The decreases in the total seed cotton yield attributed to the late planting dates (1st week of April & May) amounted 26.4 and 84.8% and 30.6 and 84.1% of  March planting with the treatments of 10 and 20 m3/ fad organic manure, respectively.

This study was conducted at Sids Experimental Research Station, Beni Suief Governorate, starting from year 2000 to study the effect of rotation dura-tion (every year, 2- year rotation and 3- year rota-tion) and nitrogen fertilizer rates; 45, 60 and 75 kg N/ fed on growth, yield components and yield of cotton, as well as associated weeds. A split plot design was used with four replicates. The data indicated that crop rotation had significant effect on plant height, number of fruiting branches/ plant, number of open bolls, seed cotton yield/ plant and seed cotton yield/ fed. Seed cotton yield/ fed was increased by 10.99 and 23.62 % when 2-year and 3-year rotations were applied, compared to 1-year rotation (average of both seasons). In-creasing N- fertilization up to 60 kg N/ fed caused significant increases in all studied traits. The best estimate of yield (Y) plotted against N rate (X) for annually rotated cotton was the linear equation of Y =2.44 + 0.074x (R2 =0.81). Two years rotation showed a quadratic association with increasing the N rate, R2 = 0.86 and 0.88, respectively. The high-est values of total fresh weeds were 2.85 and 2.60 kg/ m2 (broad and grassy weeds) when 1-year ro-tation was applied, while the lowest values were 1.50 and 1.35 kg/ m2 when 3-year rotation was applied in the first and second season, respective-ly.

Seven cotton genotypes involving cvs. Giza 70, Giza, 77, Giza 86 and Giza 83 and the exotic varieties; Pima S7 and SeaIsland, as well as, the American Upland variety Tamcot C.E., were crossed in a diallel pattern, excluding reciprocals, in 2000 season to produce 21 F1 hybrids. Parents and F1­­'swere evaluated in 2001 season for eight economic traits. Mean squares due to genotypes were highly significant for all traits, revealing the presence of sufficient variability in the population. Significant desired negative mid and better parent heterosis were found for fiber-to-seed attachment force and days to flowering. Significant positive heterosis was also observed for yield and its components. The variances due to general combining ability (GCA) and specific combining ability, (SCA) were significant for all studied traits, indicating the importance of both additive and non additive gene action in the inheritance of these characters. The GCA/SCA ratio was found to be greater than unity, indicating predominance of additive and additive x additive types of gene action in the inheritance of these traits. Based on GCA effects, the Upland variety Tamcot C.E. proved to be the best general combiner for earliness, boll weight, seed index, seed cotton yield and lint cotton yield/ plant. Giza 83 seemed to be good combiner for fiber-to-seed attachment force, Giza 86 for lint percentage and Pima S7 for number of bolls per plant.

The study investigated the influence of traditional nitrogen, phosphorus and potassium (NPK) mineral fertilizers and nano-fertilizers on yield, and its attributes, and fiber characters of two Egyptian cotton varieties Giza 94 and Giza 96. The design of the experiment was a split- plot with four replicates. Results indicated that Giza 94 cultivar surpassed Giza 96 in agronomic characteristics, although Giza 96 exhibited the highest fiber reading. Nano-chitosan (NPK)-fertilization significantly improved the mean value of boll weight, seed yield, lint yield, lint percentage, upper half mean (UHM), fiber uniformity index, fiber tenacity, and Micronaire value in both seasons. Conversely, the most minimal values for the aforementioned characteristics were recorded with the control NPK fertilizer over the two seasons.

A pot experiment was carried out in summer season of 2006 to evaluate the different concentrations effect of foliar application of methanol and pink pigmented facultative methelotrophic bacteria (PPFM) on some growth parameters and yield of cotton plant. Data showed that, the highest growth rate value was obtained with PPFM isolates from wheat with 1% methanol. The growth rate of PPFM isolates decreased with increasing the methanol concentration. Foliar applications with 20% methanol with PPFM 3 or 4 spraying times gave the significantly highest values of cotton growth and yield parameters. Such two potent treatments increased  leaf area index (LAI) by 51.4 and 55.8 %; number of fruiting branches / plant by 53.1 and 58.0 %; number of total bolls / plant by 38.1 and 43.0 %; seed cotton weight / boll by 37.1 and 48.2 % and seed cotton yield / plant by 46.1 and 50.8, respectively than the control.

Rapid estimations of diameter minus lumen(D-L), and outer perimeter of cotton fibers (P) inmicrons, as a biological fineness of Egyptian cottoncould be calculated with satisfactory levels ofaccuracy from hair weight (H.W) in m/tex andmaturity ratio )MR) obtained from Micromat data(new F/MT instrument), using the following equations:2Circularity x 3.14 x 1.52Hs (Standard finenessDiameter (microns) or Final format (D) (microns) = 1.205 HsorCircularit y × 1.524 x 3.14 x HsPerimeter (microns) or Final format (P) (microns) = 3.7853 HsResults of the current study suggested thatmore attention should be focused on meaning andmeasurements of the three values of biologicalfineness (i.e.) diameter (D), perimeter (P) (microns)and standard fineness (Hs) m/tex. whichcan be derived from the data obtained from Micromatinstrument.