Growth, Yield and Yield Components of American Cotton (Gossypium hirsutum L.) As Affected by Cultivars and Nitrogen Fertilizer
Nitrogen stress in upland cotton addresses significant and visible shortfalls in plant growth. It is an important element both in nature and agricultural conditions, for cotton plant growth and development. To evaluate the response of different yield and yield component of high yielding upland cotton cultivars to various split applications of nitrogen fertilizer, a two season field research was conducted during 2007 and 2008. Different experimental treatments were comprised on cotton leaf curl virus (CLCV) resistant high yielding cotton cultivars i.e. CIM-496, CIM-506, CIM-534 along with different nitrogen rate of Zero, 60, 110 and 160 kg ha -1 . However, cultivar CIM-534 produced significantly the highest plants, nodes per plant and flowering buds plant -1 . While, CIM-496 showed better potential in relation to leaf area index, crop growth rate, relative growth rate and net assimilation rate (physiological), dry biomass and number of bolls m -2 (reproductive) and seed cotton, cotton seed (yield) parameters during both the seasons. On increasing N rates, vegetative characteristics of cotton like plant height, nodes plant -1 and number of flowering buds per plant significantly gave better response with each cultivar. Advanced cotton cultivars produced significantly higher total dry biomass (TDM), bolls m -2 , seed cotton, cotton seed and GOT % age on each increment in applied nitrogen. The nitrogen fertilizer rate i.e. 160 kg ha -1 proved to be the optimum for the highest cotton yield and yield components. Further fibre characteristics such as staple length, uniformity ratio and maturity ratio significantly influenced by different cultivars.
Interactive Effects of Carbon Dioxide and Nitrogen Nutrition on Cotton Growth, Development, Yield, and Fiber Quality
The consequences of elevated carbon dioxide concentrations ([CO 2 ]) and N nutrition on cotton (Gossypium hirsutum L.) growth, development, yield, and fiber quality were determined. Cotton cultivar NuCOTN 33B was grown in sunlit controlled environment chambers at three levels of [CO 2 ] (180, 360, and 720 μmol mol -1 ) and two levels of N [continuous N throughout the plant growth period (N+) and N withheld from flowering to harvest (N-)]. Leaf N concentration decreased with increasing [CO 2 ] under both N treatments. These low leaf N concentrations did not decrease the effect of elevated [CO 2 ] in producing higher lint yields at both N treatments, the response being highest for plants grown at elevated [CO 2 ] and N+ conditions. Fiber quality was not significantly affected by [CO 2 ], but the leaf N concentrations, which varied with [CO 2 ], had either a positive or a negative influence on most of the fiber quality parameters. Leaf N during boll maturation period had significant positive correlations with mean fiber length (r 2 = 0.63), fine fiber fraction (r 2 = 0.67), and immature fiber fraction (r 2 = 0.65) and negative correlations with mean fiber diameter (r 2 = 0.61), short fiber content (r 2 = 0.50), fiber cross-sectional area (r 2 = 0.76), average circularity (r 2 = 0.74), and micronafis (r 2 = 0.65). It is inferred that future elevated [CO 2 ] will not have any deleterious effects on fiber quality and yield if N is optimum. The developed algorithms, if incorporated into process-level crop model, will be useful to optimize cotton production and fiber quality.
Instrumentation and Automated Photometric Titration Procedure for Total Acidity Determination in Red Wine Employing a Multicommuted Flow System
An automated procedure for photometric titration of red wine and associated instrumentation is described. The procedure was based on the flow-batch approach implemented employing multicommutation. The photometric detection was carried out using a homemade LED-based photometer. The mixing device, LED, and photodetector were attached to the titration chamber in order to form a compact and small-sized unit. The flow system comprised an automatic injector and three-way solenoid valves, which were controlled by a microcomputer through an electronic interface card. The software, written in Quick BASIC 4.5, was designed with abilities to accomplish all steps of the titration procedure including data acquisition and real-time processing to decide about the course of titration in the following step and so forth, until the titration endpoint was reached. The usefulness of the proposed titration system was demonstrated by analyzing red wine samples. When results were compared with those obtained using the AOAC reference method, no significant difference was observed at the 95% confidence level. A relative standard deviation of ca  2% (n=9 ) was obtained when processing a typical red wine sample containing 7.3 gl -1 total acidity expressed as tartaric acid.