Browsing by Subject "Growth factors"
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Item Evaluation of seed applied plant growth regulators on cotton germination, emergence, and growth(Texas Tech University, 1998-12) Becker, William DavidSeveral PGRs, each with numerous formulations, are registered for use in cotton as foliar, seed treatment, or in-furrow applications. Manufacturers of these PGRs purport beneficial plant responses, which include more rapid germination and emergence, increased root and shoot development, increased ability to withstand various stresses, as well as increased yields. Research investigating the effects of PGRs on early season growth of cotton has shown inconsistent results. Fungicides and insecticides are routinely applied to cottonseed prior to planting because of the convenience this method of application affords. This same convenience might prove beneficial for PGR applications, but research investigating the effects of seed applied PGRs has also shown inconsistent results. Thus, the objective of this study was to investigate the effects of several commercially available plant growth regulators on germination, emergence, and early season growth of cotton when applied as seed treatments at 0.5x, 1 .0x, and 2.0x the manufacturer's recommended rates.Item Influence of Ethrel on Phenological Development in Mesquite(Texas Tech University, 1972-12) Parsons, David LNot Available.Item Use of IsoVitaleX[superscript tm] enrichment for the growth of Haemophilus somnus(Texas Tech University, 1981-05) Asmussen, Maurice DwayneThe effect of IsoVitaleX on the growth of ten strains of Haemophilus somnus was studied. A six to ten-fold increase in growth was observed as measured turbidimetrically when IsoVitaleX was added to a basal medium of brain-heart infusion broth to a final concentration of 1% (volume/volume). Thiamine pyrophosphate, a constituent component of IsoVitaleX, was found to be the growth promoting factor and would completely substitute for IsoVitaleX. An equal concentration (2.2 yM) of thiamine monophosphate promoted growth equal to that of thiamine pyrophosphate. Thiamine was nonstimulatory for all ten strains tested. When alkaline, thermal treated, brain-heart infusion broth was used as the basal medium, seven of the ten strains had an absolute requirement for thiamine monophosphate or thiamine pyrophosphate. The three remaining strains showed minimal growth when thiamine was added to this basal medium. However excellent growth was observed when thiamine monophosphate or thiamine pyrophosphate was utilized. Factor X (hemin) was found to further enhance the growth when concentrations of 5-10 yg/ml were coupled with thiamine pyrophosphate. No increase in growth was observed when factor V (nicotinamide adenine dinucleotide) was coupled with thiamine pyrophosphate. This is the first report of a growth factor requirement for Haemophilus somnus.