To maximize profitability, cotton (Gossypium hirsutum L.) producand As. Elms et al. (1997) reported that yield in an ers must attempt to control the quality of the crop while maximizing irrigated cotton field in Texas displayed spatial correlayield. The objective of this research was to measure the intrinsic variability present in cotton fiber yield and quality. The 0.5-ha experi-tion. These authors also noted that production of fruitmental site was located in a producer's field (Norfolk-Coxville soil ing sites and fruit retention was spatially correlated. association) in Florence, SC, for 2 yr (1996 and 1997). Soil (0-20 cm) Micronaire exhibited a moderate degree of spatial variand fiber samples (1-m row) were collected from a regular grid (129.2 ability, and strength showed the lowest degree of variby 45.6 m, 7.6-m interval). Soil properties determined included soil ability.
The emergence of Bayesian methodology has facilitated respondent-level conjoint models, and deriving utilities from choice experiments has become very popular among those modeling product line decisions or new product * Co-chairs. Author order is alphabetical.
ALLENBY ET AL.introductions. This review begins with a paradox of why experimental choices should mirror market behavior despite clear differences in content, structure and motivation. It then addresses ways to design the choice tasks so that they are more likely to reflect market choices. Finally, it examines ways to model the results of the choice experiments to better mirror both underlying decision processes and potential market choices.
With green sugarcane (interspecific hybrids of Saccharum spp.) harvesting, 6 to 24 Mg ha 21 of postharvest residue is deposited on the field surface covering the sugarcane stubble that must reemerge for several ratoon crops. The objectives of this research were to: (i) determine if postharvest residue possesses allelopathic, autotoxic, and hormetic properties; (ii) determine the interaction of soil type with possible autotoxic effects; and (iii) identify a reliable indicator species. Extract concentrations consisted of 0, 0.1, 10, 25, and 100% of the original solution of a 1:28 tissue to water extract. The higher concentrations of residue extracts exhibited autotoxicity by delaying early leaf development. The lower extract concentration of 10% increased sugarcane bud germination by 45% compared with the control, indicating hormetic effects. Allelopathic activity on tall morninglory (Ipomoea hederacea Jacq.) was more pronounced on a light soil; germination and radical length were reduced by all concentrations by an average of 42% and 8 mm, respectively, compared with the control. Seedling dry weights were reduced by an average of 10 mg by the 10, 25, and 100% extract concentrations relative to the control. On the heavy soil, only the 100% concentration reduced radical length and weight by 5 mm and 4 mg, respectively, relative to the control. Extract effects on oat (Avena nuda L.), rye (Secale cereale L.), and tomato (Lycopersicon esculentum Mill.) showed poor correlation with effects on sugarcane. Chemical analysis by gas chromatography/ mass spectrotometry indicated the extract contained benzoic acid. Further studies are needed to establish the impact of benzoic acid in natural settings.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.