Office of the Dean (CAFES) Scholarship Copyright (c) 2013 California Polytechnic State University All rights reserved. http://digitalcommons.calpoly.edu/cafes_dean Recent documents in Office of the Dean (CAFES) Scholarship en-us Wed, 01 May 2013 13:15:48 PDT 3600 Metabolic Heat: A New Way of Looking at How Controlled Atmospheres Kill Insects http://digitalcommons.calpoly.edu/cafes_dean/36 http://digitalcommons.calpoly.edu/cafes_dean/36 Wed, 07 May 2008 11:12:49 PDT The use of calorimetry as a tool to understand the effects of controlled atmospheres (CA) on insects is briefly reviewed. A variety of data are presented to illustrate the various types of information that calorimetry can make available to researchers. The use of a calorimeter connected to a mass spectrometer to determine the occurrence of anaerobic respiration is described and reported. We conclude that calorimetry is a useful tool to simplify the experimental options when developing new insecticidal CA treatments. It can also be used for development of other treatments such as fumigants.

]]> A. Carpenter et al. Review of Entomology & Pest Management, by Larry P. Pedigo, 4th Edition http://digitalcommons.calpoly.edu/cafes_dean/35 http://digitalcommons.calpoly.edu/cafes_dean/35 Wed, 07 May 2008 11:12:48 PDT Review of Entomology & Pest Management by Larry P. Pedigo, 4th edition, Prentice Hall, 2002, 742 pp., Hardbound. $78.75.

]]> Mark D. Shelton Iron Fertilization of Kentucky Bluegrass http://digitalcommons.calpoly.edu/cafes_dean/34 http://digitalcommons.calpoly.edu/cafes_dean/34 Tue, 06 May 2008 16:55:07 PDT Iron applications are sometimes used to enhance the color (darker green) of turfgrass stands even when iron is not deficient. A study was conducted to determine the feasibility of replacing a portion of the total yearly N applied to Kentucky bluegrass (Poa pratensis L.) with iron. Turfgrass response to iron chelate (Sequestrene 330) applications at 2.2 kg Fe ha-1 in combination with three liquid-applied N sources (urea, Formolene, and FLUF) at 25 kg N ha-1 was compared to turf response from applications of the N sources at 49 kg N ha-1. Iron was substituted for part of the N in either the first and second, second and third, or third application in a four application per year program. The study was conducted for three years, and the fertilized turf was rated for color weekly during the growing season. Depending on N source and frequency of Fe application, turf treated with N received higher color ratings compared to turf receiving Fe + N on 13 (Formolene + Fe in third application) to 36% (Fluf + Fe in first and second application) of the rating dates. Turf color was judged acceptable on 78 to 85% of the rating dates for turf treated with N and 62 to 85% of the rating dates for turf treated with Fe + N. The results indicate that it is feasible to substitute iron for a portion of the N in a urea or Formolene fertilization program but that caution should be used when replacing N from FLUF with iron.

]]> David J. Wehner et al. A Microecosystem for Fertilizer and Pesticide Fate Research http://digitalcommons.calpoly.edu/cafes_dean/33 http://digitalcommons.calpoly.edu/cafes_dean/33 Wed, 30 Apr 2008 15:04:04 PDT A microecosystem was designed to study the behavior of pesticides, fertilizers, or related compounds applied to plant stands. The system consists of three parts: a brass base that holds the plant growth media, a glass atmospheric chamber that rests on the base, and a set of analytical traps. The brass base is fitted with a porous ceramic plate so that tension can be applied to the water in the growing media. Air enters the bottom of the glass atmospheric chamber and exits through the top into appropriate trapping systems to recover volatilized pesticides, ammonia, or metabolized 14CO2 from labeled compounds. A port at the base of the chamber allows collection of leachate. The microecosystem was evaluated by applying N sources or a pesticide to intact turfgrass profiles and monitoring the fate of the applied compound. Leaching and volatilization losses of N ranged from 0 to 17% and 0.1 to 17% of the applied N, respectively, depending on N source, soil conditions, and whether tension was applied to the base of the system. Three weeks after the application of radiolabeled diazinon [O,O-diethyl-0-(2-isopropyl-4-methyl•6primidinyl) phosphorothiote] to a turf, 47% of the label remained in the form of the parent compound, 22% had been metabolized and lost as 14CO2, 1% had leached through the profile, 2% had been lost through volatilization, and 28% remained in the soil as a metabolite or in unextractable compounds. The microecosystem has proven to be an invaluable tool for turfgrass research and should be useful for fertilizer and pesticide fate studies with other crops.

]]> B. E. Branham et al. The Fate of Diazinon Applied to Thatched Turf http://digitalcommons.calpoly.edu/cafes_dean/32 http://digitalcommons.calpoly.edu/cafes_dean/32 Wed, 30 Apr 2008 15:04:01 PDT Diazinon (0,0-diethyl-0-(2-isopropyl-6-methyl-4-primidinyl) phosphorothioate) is widely used to control turfgrass insect pests. Poor control of soil-inhabiting insects has been found where diazinon has been applied to thatched turfgrass stands. The purpose of this study was to evaluate the environmental fate of diazinon applied to turfgrass stands. A microecosystem was used to follow the fate of radiolabeled diazinon surface applied to Kentucky bluegrass (Poa pratensis L.) turfs, with or without a thatch layer, growing on Flanigan silt loam (fine, montmorillonitic, mesic Aquic Argiudoll) irrigated daily or every 4 days. Loss of diazinon by volatilization, leaching, and degradation accompanied by release of 14CO2 or incorporation of label into soil compounds was measured. The most degradation of parent compound occurred on turf containing a thatch layer irrigated daily where only 7% of the applied diazinon remained after 3 weeks. Between 32 and 47% of the parent compound remained in either turf with thatch irrigated every 4 days or turfs without thatch. The majority of the diazinon (96%) remained in the top 10 mm of the turf profile regardless of whether this was thatch or soil. In the presence of thatch, there was an accelerated rate of diazinon degradation as measured by release of 14CO2 from the two position on the pyrmidine ring. Increasing irrigation frequency on the thatched turf did not cause an increase in leaching but did increase diazinon breakdown. The results of the study suggest that where thatch is present, reduced control of insects is due both to a failure of the insecticide to move through the thatch and an increased rate of degradation.

]]> B. E. Branham et al. Navel Orangeworm (Lepidoptera: Pyralidae) Development in Sunburned Walnuts http://digitalcommons.calpoly.edu/cafes_dean/31 http://digitalcommons.calpoly.edu/cafes_dean/31 Wed, 30 Apr 2008 11:25:02 PDT Navel orangeworrns, Amyelois transitella (Walker), completed development in sunburned walnuts late in the growing season, but moths did not emerge until after harvest. Sunburned walnuts were not attractive to ovipositing moths until considerable hull damage occurred. Only sunburned walnuts with undamaged kernels were suitable for larval development. Navel orangeworrn infestation levels up to 38% were recorded in sunburned walnut samples from the San Joaquin Valley, CA. Nut hull tissue damaged by sunburn was not selected over undamaged hull tissue for moth oviposition. Mean kernel temperatures of sunburned walnuts were higher than both undamaged walnuts and ambient air temperature. Premature hullsplit occurred in sunburned walnuts of both early and later maturity varieties. These data suggest that, although sunburned walnuts contribute to the seasonal buildup of navel orangeworms, the late development of navel orangeworms in these nuts reduces the incidence of infestation in hullsplit, new crop nuts.

]]> Mark D. Shelton et al. Beekeeping Laboratory Manual http://digitalcommons.calpoly.edu/cafes_dean/30 http://digitalcommons.calpoly.edu/cafes_dean/30 Wed, 30 Apr 2008 11:25:01 PDT Beekeeping Laboratory Manual: FRSC 123.

]]> Mark D. Shelton et al. Denitrification Losses from Kentucky Bluegrass Sod http://digitalcommons.calpoly.edu/cafes_dean/29 http://digitalcommons.calpoly.edu/cafes_dean/29 Wed, 30 Apr 2008 10:56:33 PDT Denitrification may represent an important mechanism in the fate of N applied to turf. Denitrification losses were directly measured from fertilized 'Baron' Kentucky bluegrass (Poa pratensis L.) sod samples sealed in acrylic chambers using the acetylene inhibition technique. Losses were correlated with soil texture, percent soil saturation (SAT), and temperature. Losses from turf on a Hadley silt loam soil and Hadley silt soil (both coarse-silty, mixed, nonacid, mesic Typic Udifluvents) incubated at 22°C did not exceed 0.4 and 0.1%, respectively, of the applied potassium nitrate fertilizer (4.5 g N m-2) when soil water levels were less than 75% saturated. Soil saturation increased denitrification losses from the silt loam and silt soils to 2.2 and 5.4% of the applied N, respectively. The relationship between percent soil saturation and denitrification loss was quadratic and highly significant for both soils. The equations are: milligrams of N2O – N m-210 d-1 = 1432.50 – 38.96 (percent SAT silt soil) + 0.26 (percent silt soil)2 or 130.80 -5.40 (percent SAT silt loam soil) + 0.05 (SAT silt loam soil)2. A linear relationship [milligrams of N2O m-2 10 d-1 = 0.49(°C) – 9.70] existed between denitrification losses and soil temperatures between 22 and 30°C in the silt soil at 75% of soil saturation. Soil temperatures of 30°C or greater coupled with saturated soil conditions resulted in the greatest losses, equivalent to 44.6 and 92.6% of the applied N to the silt loam and silt soils, respectively. Denitrification losses did not increase at soil temperatures above 30°C. These results indicate that denitrification loss from fertilizers applied to turfgrasses may not be a serious problem unless the soils are saturated and at higher soil temperatures.

]]> C. F. Mancino et al. Heat Tolerance Screening of Field-Grown Cultivars of Kentucky Bluegrass and Perennial Ryegrass http://digitalcommons.calpoly.edu/cafes_dean/28 http://digitalcommons.calpoly.edu/cafes_dean/28 Wed, 30 Apr 2008 09:30:40 PDT The quality of cool-season turfgrasses frequently declines during periods of high temperature stress. Simple tests are needed to rapidly identify heat tolerant germplasm for incorporation into breeding programs. Facilitative screening tests have been devised, however, in the few studies that have been performed only immature and greenhouse or growth chamber-grown plants have been evaluated. To be of practical value, results of screening tests, employing plants grown under artificial conditions, should correlate closely with results of tests involving field grown plants. The objective of this research was to evaluate the heat tolerance of several cultivars of Kentucky bluegrass (Poa pratensis L.) and perennial ryegrass (Lolium perenne L.) grown in the field under four different regimes of N fertilization (0, 98,148, or 196 kg ha-1 yr-1) in a Typic Hapludults, fine silty, mixed mesic soil for comparison with published results in which greenhouse and growth chamber-grown material was used. On six sampling dates, plants representing all cultivar and N combinations were exposed to 42, 44, and 46°C by immersion in a water bath. Heat tolerance of the cultivars was compared using the mean percent recovery weight for the three temperatures. The Kentucky bluegrass cvs. Sydsport, Vantage, and Pennstar were more heat tolerant than the perennial ryegrass cvs. Pennfine, Citation, and Caravelle. When data were averaged over 2 years, it was shown that Sydsport was significantly more heat tolerant than all other genera and cultivars tested. Pennfine had higher recovery weights than the other two ryegrasses on four of six sampling dates. When data were averaged, however, no significant heat tolerance differences among the ryegrasses were discerned. The results from the screening of field grown material followed the same trends as published results using greenhouse or growth chamber-grown samples. This investigation therefore provides strong evidence that laboratory screening tests may be used to identify accurately and rapidly heat tolerant cultivars of Kentucky bluegrass and possibly perennial ryegrass. The overall heat tolerance of the cultivars on each sampling date correlated with the amount of precipitation (r= -0.91) and the average high temperature (r=0.93) for the period just prior to and during sampling. The moderate N fertility regimes imposed had little effect on the heat tolerance of the grasses.

]]> D. D. Minner et al. Phenology of the Western Cherry Fruit Fly (Diptera: Tephritidae) in Utah and Washington http://digitalcommons.calpoly.edu/cafes_dean/27 http://digitalcommons.calpoly.edu/cafes_dean/27 Fri, 25 Apr 2008 15:27:11 PDT The flight period of the western cherry fruit fly, Rhagoletis indifferens Curran, was investigated in Utah tart cherry, Prunus cerasus L., orchards from 1983 to 1989 and in Washington sweet cherry, Prunus avium L., orchards between 1982 and 1988. In Utah, flies were first detected on 31 May 1989, but the average time of first detection was 9 June across nine site-years. In Washington, the first fly was detected on 23 May 1988, with an average first detection time of 1 June in the three site-years. On a degree-day (DD) scale (lower threshold of 5°C and no upper threshold), detection of the first fly averaged 573 ± 19.0 DD (x̄ ± SEM) in Utah and 592 ± 42.1 DD in Washington. A degree-day model using the combined data for Utah and Washington consistently predicted emergence for all but one Utah site without synchronization of the model based on capture of the first fly.

]]> Vincent P. Jones et al. Perceptions of Agriculture and Natural Resource M.S. Graduates Regarding Program Quality and Learning Outcomes Attainment http://digitalcommons.calpoly.edu/cafes_dean/26 http://digitalcommons.calpoly.edu/cafes_dean/26 Fri, 25 Apr 2008 15:27:09 PDT Master's degree recipients from the College of Agriculture, Food and Environmental Sciences (CAFES) at Cal Poly State University were surveyed to assess 1) their satisfaction with the M.S. program, and 2) the extent to which key learning outcomes were attained. Emphasis was placed on the graduate's perception of the value of their thesis or creative project experience in developing technical competency and skills in communication, critical thinking, problem-solving, leadership, and decision making.

CAFES M.S. alumni were generally positive in their perception of the graduate program, though written comments indicated dissatisfaction with various program aspects among some graduates. Most respondents felt their professionally related skills (e.g. communication, leadership, problem-solving, etc.) were enhanced by their graduate school experience.

Students who completed a thesis reported significantly higher levels of skill development in writing, analytical methods, and research competency, compared to non-thesis students. Further, the educational value and challenge of a written thesis were considered significantly greater by students than for creative projects or internships.

Most respondents were satisfied with faculty mentoring and considered the M.S. program helpful in career advancement.

]]> Mark D. Shelton et al. Occurrence of Farming Practices in Idaho: With Special Reference to Remote Sensing http://digitalcommons.calpoly.edu/cafes_dean/25 http://digitalcommons.calpoly.edu/cafes_dean/25 Fri, 25 Apr 2008 15:27:08 PDT This survey of information was initiated and compiled because of the needs of remote sensing interpreters to identify crops throughout the year on various types of remote sensing imagery. A fairly comprehensive guide to what crops grow in a county and the specific cropping practices has been developed.

]]> Mark D. Shelton et al. Introduction to Fly Fishing http://digitalcommons.calpoly.edu/cafes_dean/24 http://digitalcommons.calpoly.edu/cafes_dean/24 Fri, 25 Apr 2008 15:27:06 PDT Mark D. Shelton High-Temperature Controlled Atmosphere for Post-Harvest Control of Indian Meal Moth (Lepidoptera: Pyralidae) on Preserved Flowers http://digitalcommons.calpoly.edu/cafes_dean/23 http://digitalcommons.calpoly.edu/cafes_dean/23 Fri, 25 Apr 2008 14:08:25 PDT High carbon dioxide atmospheres combined with high temperature were effective for controlling Indian meal moth, Plodia interpunctella (Hübner) pupae. Pupae were exposed to atmospheres of 60, 80, or 98% carbon dioxide (CO2) in nitrogen (N2), or 60 or 80% CO2in air at temperatures of 26.7°C or 32.2°C and 60% RH. Controlled atmosphere treatments at 32.2°C controlled pupae faster than the same treatments at the lower temperature. At both temperatures high CO2 concentration treatments combined with nitrogen killed pupae faster than high CO2 concentration treatments combined with air. Exposure to 80% carbon dioxide mixed with nitrogen was the most effective treatment causing 100% mortality in 12 h at 32.2°C and 93.3% mortality in 18 h at 26.6°C. High-temperature controlled atmosphere treatments had no adverse effects on quality of two preserved floral products, Limonium sinuatum (L.) and Gypsophila elegans (Bieb.), tested for 12, 18, and 24 h according to industry standards.

]]> Jodi A. Sauer et al. Enterprise Projects: Experiential Learning in Applied Entomology http://digitalcommons.calpoly.edu/cafes_dean/22 http://digitalcommons.calpoly.edu/cafes_dean/22 Fri, 25 Apr 2008 14:08:24 PDT During 1924, when jobs for college students were difficult to find in San Luis Obispo, Calif., a group of entrepreneurial students at the California Polytechnic School negotiated an $80 bank loan from a local lender to raise chickens. Parents and college faculty cosigned the loan, and thus was born the Agricultural Enterprise Program.

]]> Mark D. Shelton Effects of Weeds on the Diversity and Abundance of Insects in Soybeans http://digitalcommons.calpoly.edu/cafes_dean/21 http://digitalcommons.calpoly.edu/cafes_dean/21 Fri, 25 Apr 2008 14:08:22 PDT Sweep-net sampling and pitfall trapping were used to survey insects in weedy and weed-free soybean habitats. Weedy soybean habitats consisted of (1) grassy soybeans; (2) soybeans with broadleaf weeds; and (3) soybeans with broadleaf weeds and grasses. Insect species diversity was greater in weedy soybean habitats than in weed-free soybeans. Greatest diversity of species occurred in the mixed-weed soybean habitat. The most important phytophagous insect on soybeans in Indiana, the Mexican bean beetle, Epilachna varivestis Mulsant, was most abundant in weed-free soybeans. Predators were most ahundant in weedy soybeans. Coleomegilla maculata (DeGeer) was most abundant in weedy soybean habitats, whereas Orius insidiosus (Say) and Nabis spp. were most abundant in soybean habitats with grasses and mixed weeds. In the pitfall trapping study, Harpalus spp. were more abundant in soybean habitats with grasses and mixed broadleaf and grass weeds.

]]> Mark D. Shelton et al. Utilizing Iron In Turfgrass Management http://digitalcommons.calpoly.edu/cafes_dean/20 http://digitalcommons.calpoly.edu/cafes_dean/20 Fri, 25 Apr 2008 13:09:52 PDT The purpose of this article is to review some of the basic information on iron, look at one of the discoveries made during the 1980s, and present some of the published research studies that have been conducted with iron on turfgrasses. Additional information on the use of iron can be found in popular magazines and in the proceedings of turfgrass conferences.

]]> David J. Wehner Urease Activity in a Kentucky Bluegrass Turf http://digitalcommons.calpoly.edu/cafes_dean/19 http://digitalcommons.calpoly.edu/cafes_dean/19 Fri, 25 Apr 2008 13:09:49 PDT The components of a turfgrass ecosystem, including plants, an intervening layer of thatch and the underlying soil, influence the fate of topically applied urea fertilizer. The loss of urea N by ammonia volatilization may be governed by the rate of urea hydrolysis. The main objective of this study was to determine the extent of urease activity associated with turfgrass plant tissue, thatch, and the underlying soil. This information may help elucidate the mechanism of ammonia loss following urea application. Because a turfgrass stand frequently possesses an extensive thatch layer that may serve as the primary plant growth medium, additional objectives included: i) determining the effects of air drying and seasonal variation on the activity of urease in thatch; ii) determining the variability in thatch urease activity by analyzing multiple field samples; and iii) determining the variation of urease activity within a thatch profile. Turfgrass clippings, thatch, and underlying Flanagan silt loam soil (Aquic Argiudoll) samples were taken from a field-grown Kentucky bluegrass (Poa pratensis L.) turf in either September 1980 or March 1981. On a dry weight basis, urease activity was 18 to 30 times higher from turfgrass clippings and thatch than from soil. Air drying thatch increased urease activity by 20 % over moist samples while air drying soil samples had no apparent effect. Greenhouse incubation of winter-dormant thatch samples increased urease activity 40 %, presumably in response to the duration of increased temperature. Thatch urease activity varied between sampling sites but still remained extremely high compared to soil activity. Within each thatch sample (1 X 1 X 2 cm), urease activity was highest in the upper 1.0 cm of the profile. It was concluded that thatch urease activity was variable in nature depending upon seasonal conditions which contrasts sharply with extremely stable soil urease activities. These findings suggest that, because of the high level of urease in thatch, ammonia volatilization will occur from most urea-treated turfgrass stands, regardless of the type of underlying soil unless the urea is thoroughly washed into the soil.

]]> W. A. Torello et al. Separation of Kentucky Bluegrass Cultivars Using Peroxidase Isoenzyme Banding Patterns http://digitalcommons.calpoly.edu/cafes_dean/18 http://digitalcommons.calpoly.edu/cafes_dean/18 Thu, 24 Apr 2008 16:16:48 PDT The peroxidase isoenzyme banding pattern of 15 Kentucky bluegrass (Poa pratensis L.) cultivars was investigated for use in identification. Isoenzymes were separated by polyacrylamide slab gel electrophoresis, stained with benzidine-H2O2, and the relative intensities of the bands evaluated with a densitometer. Cultivar separations were made on single seedling samples at the 1% level of confidence using band number, mobility, and intensity ratios. Overall variability of the procedure was evaluated using a horseradish peroxidase standard and the effects of seedling age and seedlot determined. Of the 15 cultivars, 11 could be separated individually, whereas the remaining 4 were grouped into two pairs. Band mobilities for the standard and the cultivars varied 1 to 3%, whereas intensity ratios varied 9% for the standard, and 5 to 20% for most cultivars. Neither seedlot, seedling age, nor leaf position on the same seedling affected the peroxidase isoenzyme banding pattern.

]]> David J. Wehner et al. Heat Tolerance of Kentucky Bluegrasses, Perennial Ryegrasses, and Annual Bluegrass http://digitalcommons.calpoly.edu/cafes_dean/17 http://digitalcommons.calpoly.edu/cafes_dean/17 Thu, 24 Apr 2008 15:58:13 PDT Use of cool-season turfgrasses in transitional environments is limited, in part, by their heat tolerance. Development of a rapid heat tolerance screening technique would be of value in determining the potential of turf•grasses for use in warmer areas.

The heat tolerance of 22 Kentucky bluegrass (Poa pratensis L.) cultivars, Poa annua L., and four perennial ryegrass cultivars (Lolium perenne L.) was evaluated by exposing plants for 30 min to temperatures ranging from 41 to 49 C in single degree intervals. Ten-week-old plants, which had been grown under a low level of N fertilization and watered infrequently to maximize heat tolerance development, were sealed in plastic bags, placed in a constant temperature water bath for treatment, and then replanted. Recovery was evaluated by visually rating the plants 4 weeks after treatment or by harvesting and weighing plants 2 weeks after treatment and expressing the weight as a percentage of the weight of a non-stressed control (referred to as recovery weight). Cultivar comparisons were based on the average recovery weight over a given temperature range.

Initial injury occurred at 41 to 43 C with complete kill at 47 to 49 C. Kentucky bluegrass was more heat tolerant than Poa annua L. and perennial ryegrass. Heat tolerance of the latter two species was approximately equal. The Kentucky bluegrass cultivars tested were similar in heat tolerance. Among the ryegrasses, 'Loretta' was less heat tolerant than 'Diplomat', 'Pennfine', and 'Citation'. Of all the grasses, 'Sydsport' Kentucky bluegrass ranked the highest and Loretta perennial ryegrass the lowest in heat tolerance. The correlation between dilute acid extractable carbohydrate reserves and recovery weight for these five cultivars was not significant. There was a significant negative correlation between recovery weight and Fe and Al concentration.

]]> David J. Wehner et al.