Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Effect of an upper temperature threshold on heat unit calculations, defoliation timing, lint yield, and fiber quality in cotton.
Effect of an Upper Temperature Threshold on Heat Unit Calculations, Defoliation Timing, Lint Yield, and Fiber Quality in Cotton
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Effect of an upper temperature threshold on heat unit calculations, defoliation timing, lint yield, and fiber quality in cotton.
Effect of an Upper Temperature Threshold on Heat Unit Calculations, Defoliation Timing, Lint Yield, and Fiber Quality in Cotton
Author: Daniel D. FrommePublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Crop managers need to determine the most profitable time to defoliate cotton (Gossypium hirsutum L.) in a high rainfall environment such as the coastal region of Texas. In cotton production, delaying defoliation exposes open bolls to a higher probability of rainfall, and thus, reduces lint yield and fiber quality. Premature defoliation, however, has detrimental affects on lint yield and fiber quality. A more recent method to determine defoliation is based on heat-unit (HU or DD15) accumulation after physiological cutout or five nodes above white flower (NAWF=5). Results have been inconsistent across a wide range of field environments when utilizing HU accumulation past cutout; therefore, adoption of this method has been limited. Many regions of the Cotton Belt have maximum day time temperatures during the growing season that are above optimum for maximum growth. Field studies were conducted for three consecutive growing seasons in the Brazos River Valley and Upper Gulf Coast regions of Texas. The purpose of this research was to identify an upper temperature threshold (UTT) for calculating degree days for defoliation timing. The experimental design consisted of a split-plot design with four replications. The main plots consisted of three upper temperature thresholds (32°C, 35°C, and no upper limit) and the subplots were five HU timings (361, 417, 472, 528, and 583) accumulated from date of cutout. Utilizing an UTT to calculate daily HU failed to explain differences in the optimum time to defoliate based on accumulated HU from cutout for the upper thresholds investigated. Accumulated HU had a significant impact, however, on defoliation timing. Comparison of the two locations showed that maximum lint yield was obtained at 472 HU and 52% open boll at Wharton County versus a maximum of 528 HU and 62% open boll for the Burleson County location. Employing the NACB=4 method to time defoliation at both locations would have resulted in premature application of harvest aids and reduced lint yields. No differences were observed in adjusted gross income values at Wharton County among the 417, 472, 528, and 583 HU treatments. For Burleson County, adjusted gross income peaked in value at 528 HU.
Effect of Cotton Defoliation on Yield and Quality
Author: Effect of Cotton Defoliation on Yield and Quality
Author: Heat Unit Accumulation to Determine Boll Maturity and the Impact Upon Fiber Properties and Lint Yield of Cotton
Author: Ty Kelly WittenSummary Proceedings of the Beltwide Cotton Production-Mechanization Conference
Author: Agronomy Abstracts
Author: Dissertation Abstracts International
Author: Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 580
Book Description
Effects of Different Application Dates of Defoliants and Desicccants on Fiber Quality, Spinning Performance, Seed Grade and Yield of High Plains Cotton
Author: Texas Technological College, Lubbock. Textile Research LaboratoriesPublisher:
ISBN:
Category : Cotton
Languages : en
Pages : 140
Book Description
Nodes Above White Flower and Heat Units as Indicators of Harvest Aid Timing
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The timing of harvest aid application on cotton (Gossypium hirsutum L.) is critical, and poses potential problems when mistimed. The consequences of premature harvest aid application could result in reduced profit to the grower through the need for additional applications, reduced lint yield, poor fiber quality, and/or delayed harvest. A delayed application of harvest aid materials may also reduce lint yield and fiber quality if late season inclement weather patterns are established. Currently, there are many methods utilized for determining application of harvest aid materials. One method utilizes accumulated heat units, or growing degree days (HUor DD60's), following plant physiological maturity. Physiological maturity (cutout) is identified as nodes above white flower equals 5 (NAWF=5). This method triggers the application of harvest aid chemicals when 850 HU have been accumulated beyond cutout. Due to differing environmental and edaphic characteristics across the CottonBelt, application of harvest aid chemicals at this time may be premature in terms of optimizing lint yield and fiber quality. A two-year study was established to determine the proper timing of harvest aid application for picker harvested cotton in south central Texas. The design utilized a split-plot with four replications. The main plots consisted of three nodal positions (NAWF=3, 4, and 5), and the subplots were five HU accumulations (650, 750, 850, 950,and 1050) that corresponded to each of the nodal positions. In both years, lint yields increased with an increase in HU accumulation. Greater yields were achieved when HUaccumulation was initiated after NAWF = 4. This two-year study indicates that harvest aid applications made at NAWF = 4 plus 1050 HU would optimize yield potential for picker harvested cotton in south central Texas.