الفهرس 
Effect of boll age on fiber fineness and maturityOnly 14 pages are availabe for public view
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Abstract
The present study was carried out to investigate: 1) fiber fineness and maturity of uncollapsed and collapsed fibers, 2) studying the effect of boll age, measuring method and growing season on fiber fineness and maturity, 3) Estimation of fiber fineness parameters via HVI data, 4) the relationship of fiber fineness and maturity with other fiber quality properties. Fifteen Egyptian cotton varieties and promising crosses representing all the Egyptian cotton categories were grown in Giza Reseach Station during 2006 and 2007 seasons. Fibers taken from green bolls of different five ages were used to determine fiber fineness and maturity of uncollapsed fibers. Causticaire method was used to determine fiber fineness and maturity of the swollen fibers. Cross-section image analysis technique and dry fiber microscope testing were used for measuring fiber fineness and maturity of collapsed fibers.
Combined analysis indicated that fiber diameter of uncollapsed fibers (green boll data) ranged in the studied cottons from 15.32µ in Giza45 to 19.69 µ in Giza80 while the swollen fiber diameter (Causticaire method) ranged from 14.63 in Giza45 to 18.12 µ in Giza80. Swollen fiber diameter was 2.76 – 8.53% lower than the fresh fiber diameter. Growing season did not affect fiber diameter while affected significantly fiber maturity.
Degree of thickening of uncollapsed fibers ranged from 77.26 in Giza45 to 89% in Giza80 while degree of thickening of the swollen fibers were 0.18 – 3.78% lower than those obtained from green boll data.
Boll age showed little effect on fiber diameter while affected significantly fiber maturity. Cellulose deposition was rapid in 30 and 40 days boll ages while it was very slow until boll opening.
Cross-section area and perimeter of collapsed fiber obtained from image analysis ranged from 132.70µ2 and 40.55µ in Giza45 to 222.80 µ2 and 54.80µ in Giza80.
The estimated fiber perimeter obtained from HVI data was about 2-3 µ higher than actual perimeter of the fiber cross-section of the ELS and Delta (LS) cottons while being 0.5-1.5 µ lower in Upper and Middle Egypt (LS) cottons.
Uncollapsed and collapsed fiber diameter, perimeter and cross-section area showed negative relationship with Upper half mean length (UHM), Uniformity index (UI) and fiber strength while positive relationship with micronaire value, maturity ratio and fiber elongation, however it did no show significant relationship with other fiber quality properties.