Peter Reid

Effects of the okra leaf, nectariless, frego bract and glabrous conditions on yield and quality of cotton lines

SummaryEffects on yield and quality associated with the glabrous leaf, frego bract, okra leaf and nectariless genes (singly and combined) were studied under two insecticide spray regimes (heavy and light) in field experiments repeated over three seasons. Under the heavy spray regime there were few consistent differences between mutant genotypes and the normal except for low yields associated with the glabrous leaf, nectariless, frego bract genotype and the okra leaf genotype. Under the light spray regime, genotypes containing the okra leaf gene and/or the nectariless genes were associated with higher yields than the normal and genotypes containing glabrous leaf and/or frego bract genes were associated with lower yields. Positive epistatic interactions occurred in a number of instances including the okra leaf gene in the glabrous hair, normal bract background under heavy spraying, and with all backgrounds under light spraying, and for glabrous leaf in both the okra normal and okra frego backgrounds under heavy spraying. Nectariless also interacted positively with the normal leaf, normal hair, normal bract background under light spraying. Pronounced negative epistatic interactions only occurred in the light spray regime, and included glabrous leaf in all backgrounds, and frego bract in all backgrounds except the normal leaf, normal hair. The mutant genes had only minor effects on lint quality. The implications of the results for breeding and pest management are diseussed.

Progress towards magnetotelluric time lapse monitoring of enhanced geothermal system fluids

Realization of enhanced geothermal systems (EGS) prescribes the need for novel technology to monitor fluid inclusion at depth. Magnetotellurics (MT) is a relatively cheap method that is sensitive to electrical conductivity contrasts as a function of depth. It is proposed that MT can be employed to monitor areal extent of an EGS reservoir by collecting measurements before, during and after fluids are injected. 3D forward modeling suggests changes in the MT response will be small, on the order of a few degrees in phase. Repeatability of the MT response is important and it is shown that most stations are with in a few percent. Presented are 3D forward models, repeatability confidence from apparent resistivity and phase as well as phase tensor analysis.