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Hop cone tip blight : a new disease in the Pacific NorthwestBienapfl, John C. 24 September 2003 (has links)
A necrosis at the tip of cones was observed on hop (Humulus lupulus), cultivar
"Nugget", grown in Oregon in the early 1990's. Fusarium sambucinum and F.
avenaceum were recovered from symptomatic cones in 1998 and preliminary
inoculation experiments suggested both Fusarium species could cause hop cone
necrosis. Studies were carried out to (1) examine pathogenicity and demonstrate
Koch's postulates for hop cone tip blight using isolates of F. avenaceum and F.
sambucinum obtained from hop cones; (2) examine isolates of F. avenaceum and F.
sambucinum derived from other diseased plant hosts, and other Fusarium species
derived from hop cones, for ability to cause cone necrosis; and (3) survey commercial
fields to determine Fusarium populations on 'Nugget' cone parts. Isolates ofF.
avenaceum and F. sambucinum recovered from diseased hop cones were used for
pathogenicity experiments. In addition, cone inoculations were done with single
isolates of F. avenaceum and F. sambucinum from diseased sweet corn roots, one
isolate of F. sambucinum recovered from a diseased potato tuber, individual isolates of
F. equiseti and F. oxysporum from hop cones. Cones of two hop cultivars, 'Nugget'
and 'Willamette', were collected from three different farms on three sampling dates
and inoculated with spore suspensions of hop-derived F. avenaceum and F.
sambucinum at concentrations of 10��, 1O���, and 10��� conidia/ml to examine dosage
effects. Necrosis was evaluated 2, 4, 6, and 8 days after inoculation. Percent cone
necrosis decreased as inoculum concentration of either F. avenaceum or F.
sambucinum decreased, and was lowest on water-treated cones, for all three sampling
dates. The respective Fusarium species were recovered from symptomatic cones.
Cone necrosis developed following cone inoculation with F. avenaceum or F.
sambucinum from potato or corn. Hop cones inoculated with F. equiseti or F.
oxysporum also developed necrosis, but at relatively lower levels compared to the
other Fusarium species used for inoculations. For the surveys in commercial hop
fields, burr and cone material were collected on five different dates. Fusarium
sambucinum was recovered most frequently, but F. avenaceum was also found. Both
Fusarium species were recovered from asymptomatic burr and cone materials
throughout the growing season. In general, Fusarium species, F. equiseti, F.
oxysporum, F. culmorum, F. solani, plus F. avenaceum and F. sambucinum were
found more frequently early in the season on stigmatic tissue, and Fusarium recovery
decreased as the season progressed. Fusarium prolferatum and F. monilforme were
recovered rarely. / Graduation date: 2004
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Biological control of Tetranychus urticae Koch in hops by phytoseiid mites : feasibility, spatial aspects of interactions, and managementStrong, Willard Billings, 1959- 27 April 1995 (has links)
Graduation date: 1995
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Verticillium wilt, nematodes, and soil fertility interactions in hop yardsBarth, Alexander W. 25 July 1990 (has links)
Verticillium wilt of 'Willamette' hops (Humulus
lupulus) was investigated to identifY the causal organism,
to determine the incidence of the disease, and to explore
the possibility of interactions with soil fertility and/or
nematodes. In the first year of a three year study,
sampling of yards followed a "searching for extremes
approach". Selection of yards was based on a preliminary
survey of all (35) hop growers in the Willamette Valley.
Participating growers (10) were asked to identify one "good"
and one "not-so-good" yard. Each of the 20 specified yards
was subdivided into 4 plots; two representing a "good" and
two representing a "not-so-good" area.
In all 80 plots, data were collected to determine
incidence of vascular colonization by Verticillium and stem
necrosis in vines; soil and root parasitic nematode
populations; concentrations of nitrate-N, ammonium-N, P, K,
Ca, Mg, and pH in the soil surface, and nitrate-N, ammonium-
N , and K in the subsoil; concentrations of total-P, K, and
Zn in the leaves; and concentrations of nitrate-N,
phosphate-P, and K in the petioles.
The causal agents of the wilt were Verticillium dahliae
in 13 yards and V. albo-atrum in one yard. Recovery of the
pathogen within a yard ranged from 0 to 50% of sampled
vines, while stem necrosis ranged from 0 to 68%. The
frequency of infection was not significantly different among
plots or yards, which suggests that the disease is present
in all hop growing districts in Oregon.
Soil nematode populations ranged from 0 to 3000
juveniles/100 g of dry soil. Heterodera humili (hop-cyst
nematode) was the predominant parasitic nematode, while
Pratylenchus (root-lesion nematode) and Paratylenchus (pin
nematode) were recovered only occasionally. Densities of
nematodes extracted from roots ranged from 0 to 2000
juveniles/g of moist root material and were primarily H.
humili. A significant association between nematode
populations and Verticillium incidence was not detected.
Soil nutrient concentrations exhibited a high degree of
variability among yards. The nitrate-N content, measured to
a depth of 36" (90 cm) for individual hop yards, ranged
between 65 (73) and 417 lb/A (468 kg/ha) with a mean value
of 270 lb/A (302 kg/ha). Concentrations of ammonium-N were
determined to be approximately one-fourth of the nitrate
concentrations. Phosphorus and potassium concentrations
ranged from 55 to 155 ppm and 118 to 799 ppm, respectively,
in the surface soil. For the same depth, soil pH ranged
from 5.15 to 6.78.
Petiole concentrations of nitrate-N and potassium
ranged from 0.16 to 1.3% and from 1.26 to 6.84%,
respectively. While it is believed that the duration of the
sampling period may have been responsible for the wide range
in nitrate-N values, petiole potassium concentrations are
thought to reflect the potassium content in the soil. The
concentrations of K in petioles increased steadily with
increasing soil test values up to 350 ppm K.
Soil and tissue nutrient concentrations found within
and among hop yards did not correlate significantly with the
incidence of Verticillium wilt. However, petiole nitrate-N
concentrations were significantly higher (p < 0.05) in plots
infected with Verticillium (0.73%) as compared to noninfected
plots (0.56%). / Graduation date: 1991
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Skirtingų apynių veislių (Humulus lupulus L.) eterinių aliejų analizė / Different varieties of hops (Humulus lupulus L.) essential oils analysisDzikas, Paulius 05 June 2008 (has links)
Darbe buvo koncentruojamasi ties eterinių aliejų tyrimais. Šie tyrimai yra aktualūs, nes nustatoma vis daugiau naudingų savybių, kurias turi junginiai esantys eteriniuose aliejuose. Kai kurie junginiai veikia įvairius neurotransmitorius, kai kurie virusus, o kai kurie netgi genus. Dėl šių priežasčių buvo atliekamas įvairių apynių ekstraktų tyrimas. Buvo tiriamos daugiau nei 20 veislių ekstraktų iš kurių žaliavos buvo gaminami trijų tipų ekstraktai: superkritinių skysčių pagalba gautas apynių spurgų ekstraktas, vandens distiliacijos būdu gautas ekstraktas ir apynių stiebų superkritinių skysčių ekstrakcijos pagalba gauti ekstraktai. Gautų ekstraktų komponenčių detekcija ir atpažinimas buvo vykdomas Shimadzu QP2010 DC-MS su autoinjektoriumi. / The composition of essential oil in hops depends mainly on hop variety and less on growing, processing and storage conditions. They can be used in medicine, brew and etc.. Essential oils can effect some neurotransmitors, viruses, gene, metabolism in many ways. That’s way is so important to research essential oils of hops. The research was concentrated on determination of components of essential oils were extract in two ways. We analized not only coins of hops, but also tried to detect essential oils in stem. Determination of compounds were execute using Shimadzu QP2010 GC-MS system with autoinjector. After that results of analysis were processed with statistical program. Assay didn’t surprised, but to reach good reliability hops needed not only researches of essential oils, but also and other material you can found in them.
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Human bitterness detection thresholds of hop acids in beer and honey /Kolpin, Kathryn M. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 80-84). Also available on the World Wide Web.
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Effects of hops β-acid extract (Humulus lupulus L.) on cattle performance and fermentation by ruminal microbesAxman, Justin January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / James S. Drouillard / Hops β-acid extract was fed to 80 heifers (389 ± 23.6 kg initial BW) to assess impact on feedlot performance and ruminal fermentation. Heifers were randomly assigned to individual pens and fed once daily for 147 d. Treatments were a control (no additive); 33 mg monensin (Elanco Animal Health, Greenfield, IN)/kg diet DM; and 10, 25, 50 mg β-acid extract of hops (DSM Nutritional Products, France)/kg diet DM. Ruminal fluid was collected on d 44 and 86 by rumenocentesis for analyses of VFA, lactate, and NH[subscript]3 concentrations. Cattle were harvested at a commercial abattoir on d 147. Hops β-acids decreased propionate (P = 0.01) concentrations and increased caproate (P = 0.05), A:P (P = 0.04), and ammonia concentrations (P = 0.03) compared to monensin. Growth performance of heifers fed β-acid or monensin was not different than that of heifers fed the control diet. Additionally, two in vitro studies were conducted to evaluate effects of hops β-acid extract on starch fermentation by mixed microbial populations from the bovine rumen. In trial 1, 2 treatments were assigned in triplicate to fermentation bottle, fitted with Ankom[superscript]RF1 Gas Production System modules (Ankom[superscript]RF Technology, Macedon, NY) using starch as substrate (Difco Soluble Starch; Dickinson and Company, Sparks, MD) and either 0 or 33 mg hops β-acid extract (10.99% active hops beadlet; DSM Nutritional Products, France)/kg substrate. Gas production was measured over 30 h. Terminal pH, IVDMD, and VFA and lactate were measured after 30 h of fermentation. Gas production increased in response to β-acid (P ≤ 0.05). Terminal pH, IVDMD, VFA, and lactate were unaffected by addition of β-acid extract (P ≤ 0.05). In trial 2, pH, VFA concentrations, and IVDMD were measured at 6-h intervals during a 30-h incubation period using 36 fermentation tubes. There was no effect of hops β-acid on in vitro fermentation (P > 0.05). In conclusion, under the conditions of these experiments, hops β-
acid extracts hops had little impact on feedlot performance, though there are indications of an impact on ruminal fermentation.
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The Effect of Alcohol and Bitterness Levels on Brewing Yeast ViabilityBryant, Nichole Elizabeth 01 March 2019 (has links)
Two of the most popular beer styles within the craft brewing industry are India Pale Ales (IPA’s) and those with high alcohol by volume (ABV). Production of these styles requires high gravity fermentation and high amounts of bittering hops in order to reach the required values for ABV and International Bitterness units (IBU) respectively. The aim of this study was to determine the impact of high gravity fermentation and high IBU levels on yeast viability and repitching cycles.
An initial experiment on high gravity fermentations was done in order to assess the effects this variable had alone. Successive five day fermentations employing serial re-pitching were performed on worts with low (10 °P), medium (14 °P), and high (18 °P) gravity levels. The minimum viability for repitching established for this study was 85%. Once the viability of a sample fell below this minimum, it would not be suitable for repitching. It was found that increasing gravity level led to lower viabilities at the end of the fermentation period. Viability decreased further as fermentation generation increased for the high gravity samples. Yeast harvested from low gravity fermentations could be repitched up to eight times. Medium and high gravity fermentations could be repitched up to five times.
This study was repeated at single gravity levels with low (25), medium (50) and high (75) IBU levels. A loss in viability with increased IBU levels over serial re-pitching cycles in the low gravity wort (10 ºP) was observed. It was found that at the low gravity level, yeast could be repitched eight times at the low IBU level, five times at the medium IBU level, and four times at the high IBU level.
When the experiment was repeated with medium and high gravity worts, the results indicated that the compound effects of increased gravity and IBU levels significantly reduced yeast viability throughout re-pitching cycles and thus limits the number of times that this yeast could be reused when compared to low gravity and low IBU fermentations. Medium gravity fermentations could be repitched three times at the low IBU level and twice at the medium and high IBU levels. High gravity fermentations could be repitched three times at all IBU levels.
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Stanovení biologicky aktivních látek ve chmelu metodou LC/HR-MS / Determination of biologically active compounds in hops by LC/HR-MS methodJandovská, Vladimíra January 2016 (has links)
This thesis describes development and optimalization of method for identification of polyphenols compounds present in hops (Humulus lupulus L.) that have potential antimicrobial activity. Within extraction of compounds from hop, minced hop cones were applied in a growth medium, where compounds diffused into the medium and created an inhibition zone after inoculated with Streptococcus aureus. The method combining extraction with acetone a salting out using QuEChERS principles was optimized for extraction of compounds from solid growth medium. The analysis was carried out using LC/HR-MS with a quadrupole-orbitrap hybrid mass analyzer. The MS method was developed as a screening method with a subsequent fragmentation of compound of interest on the base of inclusion mass list. The compounds extracted from inhibition zone were identified either by searching against a database or their structures have been elucidated on the basis of their fragmentation spectra.
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Role vakuolárních proteinů při vývoji kvasinkových kolonií / Vacuolar proteins in development of yeast coloniesTrubitsyna, Yana January 2019 (has links)
The laboratory strains of yeast Saccharomyces Cerevisiae form colonies which can differentiate into two main cell subpopulations. U and L cells demonstrate different morphology, metabolism and stress-resistance. It was also proved that some of metabolic pathways in U cells are a similar to ones in tumor cells. The unique metabolism is activated in U cells; the TORC1 is active in these cells together with autophagy and glycogen accumulation, which are characteristic for cells with inactivated TORC1. CORVET and HOPS complexes together with vacuolar ATPase are involved in processes related to vacuolar fusion and trafficking. Also, these complexes contribute to the regulation of TORC1 activity. Vam6p is a subunit of HOPS complex and it is also involved in regulation of TORC1 acting as GEF for Gtr1p GTPase, which activates TORC1. The aim of this study was to outline whether selected subunits of mentioned complexes affect TORC1 activity in U cells. Further aim was to confirm the effect of Vam6p on selected proteins production. These proteins were chosen based on results of proteomic analysis performed in our laboratory. In order to investigate possible effects of proteins of interest absence on colonies' morphology, strains deleted in selected genes were prepared (VPS3, VPS8, VPS33, VPS41, VPH2, VAC7 a...
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Effects of storage conditions on alpha acid degradation of Indiana Grown Hops (Humulus lupulus)Geraldine Madalitso Tembo (9754958) 14 December 2020 (has links)
<p>Hop
(<i>Humulus lupulus</i> L) belongs to the
Cannabaceae family and is well-known to be a dioecious, perennial climbing
plant. The common hop is native to temperate climates, but due to its
widespread commercial use in the brewing industry, hop plants are grown
worldwide. The bittering components in hops, especially the a-acids, provide a
pleasant bitterness and characteristic flavors to beer. On their own, a-acids do not
contribute much to beer bitterness but do so after they are converted to iso-a-acids during the
kettle boil step in brewing. b-acids in hops are not as
important as a-acids,
since they only supply about a third of the bittering power as a-acids but are
mostly responsible for hops’ antimicrobial properties. The goal of this study
was to investigate the effects of storage conditions on the degradation rate of
hop constituents. Pelletized hops from two varieties grown in Knightstown, IN
were studied: Cascade (typically used as aroma hops) and Chinook (mostly used
as bittering hops). The impact of storage conditions on hop chemical
constituents, hop storage index (HSI), and color parameters was evaluated at
three storage temperatures (4℃, 25℃, 35<sup>o</sup>C) with hop pellets exposed
to two different gases in headspace (nitrogen or air) for a duration of up to
168 days (4℃ and 25℃) and 70 days (35℃). Hop acids content was determined by
UV/Vis spectrophotometry and HPLC-DAD. Results showed that increased storage
temperature decreased the a-acid concentration in hops. At 4°C and 25°C the loss in a-acids was (14.5 –
23.4%) whereas at 35°C there was a greater
loss in a-acids.
The a-acid
loss between nitrogen flushed and air exposed pellets was not significantly
different (p>0.05) except for Chinook pellets stored at 35°C. b-acids remained
mostly stable for the duration of the study; however, at 35℃ the loss of b-acids over time
became significant for both varieties. HIS values increased over time for both
varieties at 4 and 25<sup>o</sup>C, however, those values remained below the
recommended 0.40 value. At 35<sup>o</sup>C, the HSI values indicated unsuitable
hops for brewing at the end of the study for both varieties. The color
parameters L* and b* remained constant after 168 days at 4 and 25<sup>o</sup>C,
while the a* value and the hue angle showed a significant decrease with time
and increasing temperature. At the conclusion of the study it was demonstrated
that the loss in a-acids
from Cascade pellets at 35℃ was lower than the loss in Chinook, suggesting that
at high temperature the a-acids in cascade were more
stable than those in Chinook.</p>
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