Riley County Research Articles

Noninteger Dimension of Seasonal Land Surface Temperature (LST)

During the few last years, climate change, including global warming, which is attributed to human activities, and its long-term adverse effects on the planet’s functions have been identified as the most challenging discussion topics and have provoked significant concern and effort to find possible solutions. Since the warmth arising from the Earth’s landscapes affects the world’s weather and climate patterns, we decided to study the changes in Land Surface Temperature (LST) patterns in different seasons through nonlinear methods. Here, we particularly wanted to estimate the noninteger dimension and fractal structure of the Land Surface Temperature. For this study, the LST data were obtained during the daytime by a Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Depending on the time of the year data were collected, temperatures changed in different ranges. Since equatorial regions remain warm, and Antarctica and Greenland remain cold, and also because altitude affects temperature, we selected Riley County in the US state of Kansas, which does not belong to any of these location types, and we observed the seasonal changes in temperature in this county. According to our fractal analysis, the fractal dimension may provide a complexity index to characterize different LST datasets. The multifractal analysis confirmed that the LST data may define a self-organizing system that produces fractal patterns in the structure of data. Thus, the LST data may not only have a wide range of fractal dimensions, but also they are fractal. The results of the present study show that the Land Surface Temperature (LST) belongs to the class of fractal processes with a noninteger dimension. Moreover, self-organized behavior governing the structure of LST data may provide an underlying principle that might be a general outcome of human activities and may shape the Earth’s surface temperature. We explicitly acknowledge the important role of fractal geometry when analyzing and tracing settlement patterns and urbanization dynamics at various scales toward purposeful planning in the development of human settlement patterns.

Retrospective study in U.S. commercial sorghum breeding: III. Nitrogen internal efficiency

AbstractRetrospective studies are critical to investigate changes in physiological traits related to nitrogen (N) uptake and yield formation. N is a key yield‐limiting nutrient in sorghum (Sorghum bicolor L. Moench), as in most crops, so improving its N internal efficiency (NIE, yield to N uptake ratio) could increase productivity and sustainability. Understanding changes in N efficiency across time linked to carbon (C) economy can provide insights for future breeding targets. This study aims to characterize N and C dynamics (via studying changes in water‐soluble carbohydrates, WSC) of 20 commercial U.S. sorghum hybrids released from 1963 to 2017. Field trials were conducted during the 2018 and 2019 growing seasons in Riley County, KS. Seasonal changes in biomass accumulation, N uptake, and WSC were characterized during both vegetative and reproductive periods. Modern hybrids had greater NIE compared with those from the 1960s. Overall, beyond the yield gain documented for modern sorghum hybrids, the NIE increased at the expense of a reduction in grain N and, in minor proportion, due to increase in the N harvest index (NHI) at maturity for newer relative to older hybrids. Newer hybrids evidenced greater N remobilization from the stover to the grains during the reproductive period. This study demonstrates the physiological mechanisms for an increase in N and C utilization behind yield genetic gain for sorghum hybrids. Future yield gain in sorghum could be pursued by enhancing N uptake to sustain further genetic progress.

Leaf-Level Spectroscopy for Analysis of Invasive Pest Impact on Trees in a Stressed Environment: An Example Using Emerald Ash Borer (Agrilus planipennis Fairmaire) in Ash Trees (Fraxinus spp.), Kansas, USA

The most visible symptoms of emerald ash borer (EAB) (Argilus planipennis Fairmaire) infestation do not usually appear until six years after the borer’s arrival, by which time the prognosis is so grim that many communities have resorted to either heavy chemical use that only slows mortality, or clear-cutting the entire ash tree population. We utilized leaf-level spectroscopy for early detection of invasive pest-related stress, focusing on EAB as it reaches the edges of the geographic range for green and white ash trees (Fraxinus pennsylvanica and Fraxinus americana) in North America. Over the course of two full growing seasons, we sampled trees in three study areas with EAB infestation in Johnson County, Kansas, and two sample groups without infestation in Riley County, Kansas. Our method utilizes field spectrometer readings for reflectance, along with lab spectrophotometry for estimation of leaf chlorophyll and carotenoid content at several points during the growing season. Results show significant differences between pigment ratios and hyperspectral indicators between infested and non-infested ash trees, although the extent of the separation varies across the foliar season. This work has the potential to make stress diagnosis more effective, thereby improving response, and decreasing both chemical application and plant loss.

Detection of Vesicular Stomatitis Virus Indiana from Insects Collected during the 2020 Outbreak in Kansas, USA.

Vesicular stomatitis (VS) is a reportable viral disease which affects horses, cattle, and pigs in the Americas. Outbreaks of vesicular stomatitis virus New Jersey serotype (VSV-NJ) in the United States typically occur on a 5–10-year cycle, usually affecting western and southwestern states. In 2019–2020, an outbreak of VSV Indiana serotype (VSV-IN) extended eastward into the states of Kansas and Missouri for the first time in several decades, leading to 101 confirmed premises in Kansas and 37 confirmed premises in Missouri. In order to investigate which vector species contributed to the outbreak in Kansas, we conducted insect surveillance at two farms that experienced confirmed VSV-positive cases, one each in Riley County and Franklin County. Centers for Disease Control and Prevention miniature light traps were used to collect biting flies on the premises. Two genera of known VSV vectors, Culicoides biting midges and Simulium black flies, were identified to species, pooled by species, sex, reproductive status, and collection site, and tested for the presence of VSV-IN RNA by RT-qPCR. In total, eight positive pools were detected from Culicoides sonorensis (1), Culicoides stellifer (3), Culicoides variipennis (1), and Simulium meridionale (3). The C. sonorensis- and C. variipennis-positive pools were from nulliparous individuals, possibly indicating transovarial or venereal transmission as the source of virus. This is the first report of VSV-IN in field caught C. stellifer and the first report of either serotype in S. meridionale near outbreak premises. These results improve our understanding of the role midges and black flies play in VSV epidemiology in the United States and broadens the scope of vector species for targeted surveillance and control.

Integrated pigweed (Amaranthus spp.) management in glufosinate-resistant soybean with a cover crop, narrow row widths, row-crop cultivation, and herbicide program

AbstractSuccessful pigweed management requires an integrated strategy to delay the development of resistance to any single control tactic. Field trials were implemented during 2017 and 2018 in three counties in Kansas on dryland (limited rainfall, nonirrigated), glufosinate-resistant soybean. The objective was to assess pigweed control with combinations of a winter wheat cover crop (CC), three soybean row widths (76, 38, and 19 cm), row-crop cultivation 2.5 weeks after planting (WAP), and an herbicide program to develop integrated pigweed management recommendations. All combinations of the four components were assessed by 16 treatments. All treatments with the herbicide program resulted in excellent (>97%) pigweed control and were analyzed separately from the other components. Treatments containing row-crop cultivation reduced pigweed density and biomass 3 and 8 WAP in all locations compared with the 76-cm row width plus no CC treatment. CC impacts were mixed. In Riley County, Palmer amaranth density and biomass were reduced; in Reno County, no additional Palmer amaranth control was observed; in Franklin County, the CC had greater waterhemp density and biomass compared with the treatments containing no CC. Narrow row widths achieved the most consistent results of all cultural components when data were pooled across locations: Decreasing row widths from 76 to 38 cm resulted in a 23% reduction in pigweed biomass 8 WAP and decreasing row width from 38 to 19 cm achieved a 15% reduction. Row-crop cultivation should be incorporated where possible as a mechanical option to manage pigweed, and narrow row widths should be used to suppress late-season pigweed growth when feasible. Inconsistent pigweed control from CC was achieved and should be given special consideration before implementation. The integral use of these components with an herbicide program as a system should be recommended to achieve the best pigweed control and reduce the risk of developing herbicide resistance.

Effects of Cover Crops and Phosphorus Fertilizer Management on Soil Health Parameters in a No-Till Corn-Soybean Cropping System in Riley County, Kansas

Effects of Cover Crops and Phosphorus Fertilizer Management on Soil Health Parameters in a No-Till Corn-Soybean Cropping System in Riley County, Kansas

Tardigrades of North America:Dactylobiotus kansaeBeasley, Miller and Shively, 2009 Confirmed to Still Exist after 50 Years

This is the second record of occurrence for the species Dactylobiotus kansaeBeasley, Miller and Shively, 2009. Originally collected in 1963 and originally identified as Macrobiotus hastatus Murray, 1907 by Beasley in 1967, the specimen identification was transferred to the new genus Murrayon in 1988 and finally described as Dactylobiotus kansae, a new species in 2009. For 50 years the species has not been reported again in any form. Now, based on a recent collection, the species has been confirmed to still exist in Oedogonium sp. algal in the type location, a small stream passing through the Kansas State University campus, in Riley County, Manhattan, Kansas, USA (North America).

Influence of Plant Growth Stage and Temperature on Glyphosate Efficacy in Common Lambsquarters (Chenopodium album)

AbstractPlant growth stage and temperature influence the activity of glyphosate on common lambsquarters. A biotype of common lambsquarters in Dickinson County, KS (DK) was not controlled upon treatment with glyphosate in the field. In a greenhouse dose–response study, the DK biotype expressed 1.5-fold less sensitivity to glyphosate compared to a known susceptible biotype from Riley County, KS (RL). Common lambsquarters plants were treated at different growth stages (5 to 7, 10 to 12, 15 to 17, or 19 to 21 cm tall) with glyphosate at a field rate (840 g ae ha–1), and, regardless of the biotype, plants were more susceptible to glyphosate when they were 5 to 7 cm tall. Common lambsquarters plants were treated with glyphosate (840 g ae ha–1) after growing at different temperatures (25/15, 32.5/22.5, or 40/30 C day/night), and regardless of the biotype, plants were more susceptible to glyphosate when grown at 25/15 C. The results suggest that the DK biotype exhibits reduced sensitivity to glyphosate compared to the RL biotype, and glyphosate applied at field rate would be more effective on smaller common lambsquarters plants and at cooler temperatures. Common lambsquarters seedlings tend to emerge when temperatures are cooler, early in the spring relative to other summer annual weeds. Therefore, plants should be identified and treated earlier in the growing season for best efficacy with glyphosate.

A field-based assessment tool for phosphorus losses in runoff in Kansas

Nonpoint P sources from the agricultural landscape are a significant environmental problem for surface water bodies because of the promotion of eutrophication. Many states have developed P assessment tools to help differentiate land uses and their potential for P losses to surface water. Kansas has developed such a P index (PI), and the purposes of this paper are to report on the calibration of that index against data collected from four runoff studies and to explore the modification of the PI as a means to improve the predictive capability of the PI. The PI includes soil test P, rate and application method for P from fertilizers and manure, soil erosion, runoff class, distance from surface water bodies, and irrigation erosion as inputs. As originally proposed, the PI was well correlated with soluble P (<i>r</i> = 0.93) and bioavailable P (<i>r</i> = 0.94) losses but was less correlated with total P (<i>r</i> = 0.79). By modification of the PI, the <i>r</i> values improved to 0.97 for bioavailable P, 0.95 for soluble P, and 0.89 for total P. Of the 90 plots at four different sites, plots from Neosho and Franklin-1 and Franklin-2 sites were ranked as having very low and low vulnerability to P loss (82%) whereas plots in the Riley County site were ranked as high and very high vulnerability to P loss (18%) due to manure applications. Therefore, for only the Riley site, P management strategies need to be modified to reduce P losses. Moreover, additional P applications are not warranted for this site. Using soil test P as a single factor to predict P losses in runoff for our sites produced results similar to using the modified PI.

(U–Th)/He dating of kimberlites—A case study from north-eastern Kansas

Dating kimberlite intrusive rocks by radiogenic isotope geochronology often is a difficult task, complicated by both the lack of dateable minerals within kimberlite as well as significant sample alteration that can degrade samples and alter parent–daughter ratios. This study presents a new geochronologic tool for timing the emplacement of kimberlites using the (U–Th)/He system to date the cooling of common kimberlite phenocrystic and xenocrystic minerals. To demonstrate the use of this technique, new apatite, titanite, zircon, magnetite and garnet (U–Th)/He ages constrain the timing of emplacement for the Stockdale, Tuttle, Baldwin Creek, Bala, and Leonardville kimberlite pipes, located in Riley County, Kansas. Zircon from the Tuttle pipe and titanite from the Stockdale pipe yield (U–Th)/He ages of 108.6 ± 9.6 Ma and 106.4 ± 3.1 Ma, respectively. These data are consistent with new Tuttle kimberlite Rb–Sr analyses of phlogopite megacrysts that give a five point isochron age of 106.6 ± 1.0 Ma. Similarly, an apatite (U–Th)/He age of 85.3 ± 2.3 Ma from the Baldwin Creek kimberlite is in agreement with a Rb–Sr phlogopite age of 88.4 ± 2.7 Ma. These dates demonstrate that (U–Th)/He thermochronometry provides reliable timing constraints on the cooling of common kimberlite xenocrystic phases, thereby timing kimberlite emplacement. In addition to the use of more commonly used apatite and zircon (U–Th)/He thermochronometers, we produced reliable emplacement ages of 103.0 ± 7.5 Ma for the Bala kimberlite using (U–Th)/He dating of phenocrystic magnetite and an age of 98.8 ± 8.9 Ma for the Tuttle kimberlite using (U–Th)/He dating of megacrystic garnet. In contrast, kimberlitic apatite (U–Th)/He ages from the Stockdale, Bala, Tuttle, and Leonardville kimberlites yield ages ranging from 67.3 ± 4.4 Ma to 64.3 ± 5.6 Ma, suggesting a local, possibly hydrothermal reheating event resulting in resetting of the apatite (U–Th)/He clock in latest Cretaceous to earliest Tertiary time. Additional (U–Th)/He analyses of apatite from nearby sandstone and basement rocks suggest regional cooling below ~ 70 °C at ~ 165 Ma. These (U–Th)/He and Rb–Sr age data imply that the kimberlites were emplaced over a period of time from ~ 85–110 Ma with several pipes subjected to local reheating at ~ 65 Ma.

The status of the crab spider genus Tmarus in Kansas

The first record of the crab spider genus Tmarus Simon 1875 (Araneae: Thomisidae) in Kansas was the discovery of an immature female Tmarus angulatus (Walckenaer 1837) in Manhattan, Riley County (Scheffer 1904). Other studies have reported the presence of this species in scattered locations in the eastern third of the state (Fitch 1963, Guarisco et al. 2003). Recent field work has uncovered the presence of Tmarus rubromaculatus Keyserling 1880 in the vicinity of Pittsburg, Crawford County, within the Cherokee Lowlands Physiographic Province of southeastern Kansas.

Effects of Different Burn Regimes on Tallgrass Prairie Herpetofaunal Species Diversity and Community Composition in the Flint Hills, Kansas

The Flint Hills region of Kansas is the largest contiguous area of tallgrass prairie remaining today. Historically, the tallgrass prairie burned every 2–3 yr on average, but current land managers have altered burn regimes, resulting in a range of habitats from annually burned to long-term unburned. We used drift fence/funnel trap arrays and coverboards to estimate species richness, evenness, and diversity of herpetofauna within three different burn regimes: annual, 4-yr, and long-term unburned at Konza Prairie Biological Station, Riley County, Kansas. During the spring and fall of 2003–2004, 315 individuals from 20 species were captured across all burn regimes. Herpetofaunal species richness, evenness, and diversity estimates were not different between the three burn treatments. However, because of species-specific responses to individual burn regimes, community composition was significantly different between the habitats (χ2 = 158.19, df = 20, P < 0.001). Four species exhibited preferences among burn regimes, which differed significantly from independent assortment, with Eumeces obsoletus and Phrynosoma cornutum preferring annual burn treatments, Scincella lateralis preferring 4-yr burn treatments, and Diadophis punctatus preferring long-term unburned treatments. Species-specific responses were likely because of changes in vegetation structure and microhabitat (temperature and moisture content) created through different frequencies of fire disturbances. Maximizing large-scale herpetofaunal diversity across the Flint Hills' rangelands could be accomplished by creating a large number of small scale habitat types through a mosaic style burning plan.

Carrion Beetles (Coleoptera: Silphidae) of the Konza Prairie Biological Station

Pitfall traps were used to determine diversity, seasonality, and numbers of burying beetles on the Konza Prairie Biological Station (KPBS) during the summers of 1997 and 1998. Traps were baited with either beef liver (1997) or whole mouse carcasses (1997 and 1998); significantly more carrion beetles were found in traps baited with carcasses. A total of 1003 carrion beetles, representing 8 species, were trapped over the course of 1556 trap nights. One of these species, Necrophila americana Linneaus, had not previously been recorded in Riley County. One additional species was found at sites where pitfall trap bait was discarded, bringing the total number of KPBS silphid species to 9. Bait age was an important determinant in attracting silphids to pitfall traps, as numbers of beetles in the trap continued to increase with bait age up to 6 days. Grassland topography (upland vs. lowland trap sites) significantly affected the numbers of carrion beetles trapped. Grassland burn history did not affect number of carrion beetles trapped, but did seem to influence species diversity.

Kinematics, mechanics, and potential earthquake hazards for faults in Pottawatomie County, Kansas, USA

Many stable continental regions have subregions with poorly defined earthquake hazards. Analysis of minor structures (folds and faults) in these subregions can improve our understanding of the tectonics and earthquake hazards. Detailed structural mapping in Pottawatomie County has revealed a suite consisting of two uplifted blocks aligned along a northeast trend and surrounded by faults. The first uplift is located southwest of the second. The northwest and southeast sides of these uplifts are bounded by northeast-trending right-lateral faults. To the east, both uplifts are bounded by north-trending reverse faults, and the first uplift is bounded by a north-trending high-angle fault to the west. The structural suite occurs above a basement fault that is part of a series of north–northeast-trending faults that delineate the Humboldt Fault Zone of eastern Kansas, an integral part of the Midcontinent Rift System. The favored kinematic model is a contractional stepover (push-up) between echelon strike-slip faults. Mechanical modeling using the boundary element method supports the interpretation of the uplifts as contractional stepovers and indicates that an approximately east–northeast maximum compressive stress trajectory is responsible for the formation of the structural suite. This stress trajectory suggests potential activity during the Laramide Orogeny, which agrees with the age of kimberlite emplacement in adjacent Riley County. The current stress field in Kansas has a N85°W maximum compressive stress trajectory that could potentially produce earthquakes along the basement faults. Several epicenters of seismic events (<M2.0) are located within 10 km of the structural suite. One epicenter is coincident with the northwest boundary of the uplift. This structural suite, a contractional stepover between echelon northeast-trending right-lateral faults, is similar to that mapped in the New Madrid Seismic Zone, and both areas currently feature roughly east–west maximum compressive stress trajectory. Based on these similarities, the faults in Pottawatomie County have the potential for seismicity. The results demonstrate that mechanical analysis of minor structural features can improve our knowledge of local earthquake hazards.

‘More mighty than the waves of the sea’: toilers, tariffs, and the income tax movement, 1880–1913

Social movements are at once the symptoms and the instruments of social progress. Ignore them and statesmanship is irrelevant; fail to use them and it is weak. Walter Lippmann In the spring of 18...

First Report of Uromyces striatus on White Sweetclover in Kansas.

Rust was observed on leaves and stems of Melilotus alba Medik. plants in Riley County, Kansas, in November 1999. Rust reoccurred during the summers of 2000 and 2001. Uredinia were orange to reddish brown and predominately hypophyllous. Infected leaves wilted and abscised prematurely. Urediniospores were one-celled, globoid or broadly ellipsoid, and measured 20 to 25 × 18 to 22 μm. Walls were 1.0 to 1.2 μm thick, echinulate, and with three to five (mostly four) pores. Pores were equatorial, or nearly so, in approximately one half of the spores examined and scattered in the other half. Telia occurred in the fall, were sparse, amphigenous, exposed, and much darker than uredinia. Teliospores were single-celled, ovoid, subglobose or ellipsoidal, and measured 18 to 25 × 15 to 21 μm. Wall thickness was 1.3 to 2 μm. Walls had ridges approximately 1 μm wide, 2 μm apart, and arranged in a longitudinal pattern as shown in photographs of Uromyces striatus (2). Pedicels were hyaline, fragile, and short. Pathogenicity tests were conducted in growth chambers (4) with monouredinial isolate K-SC-R1 from M. alba. Pots containing plants of 80 USDA Plant Introduction (PI) core accessions representing 18 Melilotus spp. were evaluated. Total accessions tested per species were: 22 M. alba, 2 M. altissimus, 3 M. dentata, 2 M. elegans, 1 M. hirsutus, 4 M. indica, 2 M. infestus, 2 M. italica, 25 M. officinalis, 2 M. polonicus, 2 M. segetalis, 2 M. siculus, 2 M. speciosus, 2 M. spicatus, 1 M. suaveolens,2 M. sulcatus, 2 M. tauricus, and 2 M. wolgicus. Various amounts of rust developed on plants of 79 accessions; no plants of M. indica PI 234674 exhibited signs of rust. A host range study of an isolate of U. striatus from alfalfa (4) included these 18 Melilotus species; 10 were hosts. Therefore, the reactions of Medicago accessions to isolate K-SC-R1 were evaluated. These included nine alfalfa germ plasm sources representing the diversity in North American alfalfas and the cvs. Saranac and Moapa 69, which are commonly used susceptible controls in alfalfa rust evaluations. No rust resulted on any entry of Medicago sativa subsp. sativa. A few scattered, small, open uredinia occurred on plants of Medicago sativa subsp. falcata ('WISFAL' PI 560533). Of 11 Medicago lupulina PI accessions inoculated, rust resulted only on a few plants of PI 269926. All M. alba plants included as susceptible controls in all tests became heavily rusted. The causal fungus fits U. striatus Schroet. as described by uredinologists who disregard urediniospore pore position in this species. For example, illustrations of U. striatus urediniospores by Savulescu (3) show scattered pores, however, descriptions of U. striatus Schroet. in North America (1,2) specify equatorial pores. To my knowledge, this is the first report of scattered pores in U. striatus urediniospores in the United States. However, an examination of urediniospores from heavily rusted alfalfa plants collected in 2001 near Manhattan, KS and from isolate KR1 (4) also revealed urediniospores with variously distributed pores. U. striatus was reported on M. alba in Florida in 2001.

New Kimberlite Discoveries in Kansas: Magnetic Expression and Structural Setting

A total of 13 kimberlites have been located in a two-county area in northeastern Kansas along the NNE-trending trace of the Proterozoic Midcontinent Rift System, an aborted rift extending from the Lake Superior region southwestward into Oklahoma.The Kansas Geological Survey drilled three new kimberlites in 1999. They are the Baldwin Creek and Tuttle kimberlites located in Riley County and the Antioch kimberlite in Marshall County. They were discovered as part of a systematic ground follow-up of private aeromagnetic data (200–400-m-line spacing) collected by Cominco American Inc. in the early 1980's and donated to the Kansas Geological Survey in 1999. Six exposed kimberlites were discovered prior to 1970 and another four in the early 1980's, one of which is exposed at the surface.Cross-cutting major tectonic elements in NE Kansas are ideal for accommodating the intrusion of kimberlites. The major structural elements are regional NNE-trending, high-angle normal and reverse faults associated with the 1.10 Ga Midcontinent Rift System, and regional, older, high-angle normal and reverse, NW-SE striking, cross-cutting faults which offset portions of the rift. The presence of the rift is identified in regional gravity and magnetic data sets and evidenced in core and cuttings recovered from drill holes that penetrate Precambrian basement. Sedimentary rocks up to about 800 m (3,040 ft) thick and ranging in age from Ordovician to Permian overlie the Proterozoic basement.Ground magnetic surveys were conducted to model the kimberlites and to define targets for drilling and core recovery. These detailed ground magnetic data show that final emplacement of the kimberlite bodies is controlled by N40°W-striking structures, rather than the NNE-trending structures. Modeling of the magnetic anomalies shows that the contacts between the kimberlite bodies and the country rock are steeply dipping.The kimberlites are believed to be Late Cretaceous in age (about 90 my) and range in character from crater and diatreme facies in Riley County to possible hypabyssal facies in Marshall County. The three new kimberlites are buried under a shallow soil cover ranging in thickness up to 8 m (26 ft).

New Records of a Porcupine and Armadillo in Riley County, Kansas

On 16 October 1997, a female porcupine (Erethizon dorsatum) was collected on Kansas State Highway 18 near Ogden (sec. 6, T11S, R7E). Wear on teeth and degree of fusion in bones indicated that she was approximately 1.5 years old (Dodge, 1982). We removed and inspected the reproductive tract and noted an enlarged uterus, suggesting she was approaching estrus at time of death. No follicles or corpora lutea of pregnancy were observed, indicating she had not bred. These observations suggest that a breeding population may occur in Riley County and surrounding areas. Although porcupines are reported to occur throughout most of Kansas (Bee and others, 1981), eastern Kansas represents their eastern range limit in the central United States (Dodge, 1982; Pitts, LeValley, and Klinger, 1987). Kaufman and Kaufman (1994) reported two observations of porcupines in Riley County. Additionally a few porcupines had been observed in the wooded areas on the northern parts of Fort Riley in Riley County (Pitts, LeValley, and Klinger, 1987). A porcupine also was observed in the mid1990's by H. Abel (Conservation Division, Fort Riley Military Reservation, personal communication) near Milford Reservoir along the Riley County border. The specimen we obtained in 1997 is the first collected from Riley County. In Kansas, porcupines inhabit forests and riparian communities, and most specimens collected in Kansas seem to be associated with major river sys-

First Report of Powdery Mildew Caused by an Oidium sp. on White Sweetclover in Kansas.

Powdery mildew was observed on plants of white sweetclover (Melilotus alba Medik.) in Riley County, Kansas, in 1995, 1996, and 1997 but was not examined closely until 1997. White, effuse to dense, amphigenous mycelia bearing Oidium conidia were obvious by mid June. Effuse growth occurred on petioles and stems. Invaded leaflets wilted and dropped, sometimes leaving a green petiole. Signs and symptoms diminished during the warmer periods of July and August, reoccurred in September, and remained prominent until the foliage froze in November. However, on 1 December, viable, newly produced conidia were collected from scant hyphal growth on protected leaves at the base of a few plants. A sexual state was not found. Characteristics of the conidial state fit those of Erysiphe pisi (1). Powdery mildew was never observed on plants of yellow sweetclover (M. officinalis (L.) Lam.) growing among the mildewed plants of white sweetclover. This is the first report of powdery mildew on M. alba in Kansas. Reference: (1) H. J. Boesewinkel. Bot. Rev. 46:167, 1980.

Combining Ability for Protein Degradability in Alfalfa

The protein in alfalfa (Medicago sativa L.) forage is degraded extensively and quickly by ruminant animals, and N may be lost through NH3 formation. Recent research has indicated that the degradability of forage protein varies among plants. The objective of this study was to determine the relative importance of additive and nonadditive genetic effects for protein degradability traits in an alfalfa population derived from major germplasm sources. Eight alfalfa plants were intercrossed in a half‐diallel to produce 28 crossed progenies. Three replications of the crosses and parental clones were transplanted and grown in Riley County, Kansas. Protein percentages were estimated with microKjedahl, and protein degradability was estimated by degradation with the proteolytic enzyme ficin prior to microKjedahl digestion. Specific (nonadditive genetic effects) and general (additive genetic effects) combining abilities were determined for crude and soluble protein, buffer‐insoluble and undegradable insoluble protein, and the proportion of undegradable protein/total insoluble protein. Data for each variable on two harvest dates in 1993 and 1994 were used in a combined analysis. Harvest date within years was a significant source of variability for all traits. A significant genotype effect was detected for all traits except undegradable insoluble protein. General combining ability effects were significant for the remaining traits, but specific combining ability effects were significant only for soluble protein. The relative ratios of additive to nonadditive effects were 0.86 for crude protein, 0.70 for soluble protein, 0.74 for insoluble protein, and 0.80 for proportion of undegradable insoluble protein/insoluble protein. The results indicate that genetic effects for alfalfa protein degradability exist and are mostly additive. Recurrent selection procedures should be effective in reducing protein degradability in alfalfa.