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Duponchelia fovealis (Zeller) (Lepidoptera: Crambidae) is a polyphagous pest that feeds on a variety of ornamental and crop plants. At least 47 plant families have been identified as hosts for D. fovealis in literature based on empirical data and observations. This list is surely incomplete based on the broad feeding habits of D. fovealis. We sought to expand the list of known D. fovealis host plants and to identify species that may be less preferred or not fed upon by D. fovealis. We used laboratory feeding assays to measure D. fovealis consumption rate of leaf disks from 32 herbaceous plant species and 32 woody species grown outdoors throughout the Southeastern United States, and 24 tropical species typically grown as house plants. These plants were from 65 genera and 36 families. Between the 3 ornamental plant groups, we tested (herbaceous, woody, and tropical) that, after 24 h, plants in the tropical group were the least consumed by D. fovealis. After 24 h, the average proportion of leaf disks eaten by D. fovealis was 0.80 or higher for 5 herbaceous and 12 woody species. Proportions of leaf disks eaten varied at the family and genus level in many cases. Our research can improve integrated pest management of D. fovealis by informing growers that plants may be at more or less risk of infestation and damage by larvae. [ABSTRACT FROM AUTHOR]

Soybean production is greatly affected by different types of weeds such as horseweed, kochia, ragweed, redroot pigweed, and waterhemp in the midwestern region of the United States. Identification of the soybean plants and the weeds is crucial to controlling the weeds in precision agriculture. The objective of this study was to classify soybean plants and five weed species where a hyperspectral imaging camera with a spectral range of 400 to 1000 nm was used to acquire the images. To acquire the HSI images, a customized robotic hyperspectral data collection scanning platform was developed and used in the greenhouse. A total of 983 hyperspectral data cubes were captured from the greenhouse environment (n = 252, soybean; n = 731, weeds). Spectral information was extracted from the collected images and then a classification model was developed by applying partial least squares discriminant analysis (PLS-DA). To construct the calibration and validation data set, the images were each divided into 70% and 30% ratios for model training and testing, respectively. Seven types of data preprocessing techniques, including mean normalization, maximum normalization, range normalization, multiplicative scatter correction (MSC), standard normal variate (SNV), Savitzky-Golay first derivatives, and Savitzky-Golay second derivatives, were explored individually and accepted as the best preprocessing method based on the highest performance in calibration and validation results. The results showed maximum validation model performance was found at 86.2% by applying the Savitzky-Golay second derivatives preprocessing method for multiclass and 89.4% for binary class. The most important wavelength information was evaluated from the beta coefficient developed using the same preprocessing method. Finally, chemical images were generated using a best-performer model to identify the soybean plants from weeds. The generated images showed a significant difference in chemical composition between soybean and weed plants at 443 nm, 633 nm, 743 nm, and 968 nm. The correlation between these peaks and the chemical components of the plants involves a-carotenoid, chlorophyll, and moisture, respectively. This study shows promising results for the application of HSI in weed control systems for soybeans and relevant weed identification in precision agriculture applications. [ABSTRACT FROM AUTHOR]

Soybean production is greatly affected by different types of weeds such as horseweed, kochia, ragweed, redroot pigweed, and waterhemp in the midwestern region of the United States. Identification of the soybean plants and the weeds is crucial to controlling the weeds in precision agriculture. The objective of this study was to classify soybean plants and five weed species where a hyperspectral imaging camera with a spectral range of400 to 1000 nm was used to acquire the images. To acquire the HSI images, a customized robotic hyperspectral data collection scanning platform was developed and used in the greenhouse. A total of 983 hyperspectral data cubes were captured from the greenhouse environment (n = 252, soybean; n = 731, weeds). Spectral information was extracted from the collected images and then a classification model was developed by applying partial least squares discriminant analysis (PLS-DA). To construct the calibration and validation data set, the images were each divided into 70% and 30% ratios for model training and testing, respectively. Seven types of data preprocessing techniques, including mean normalization, maximum normalization, range normalization, multiplicative scatter correction (MSC), standard normal variate (SNV), Savitzky-Golay first derivatives, and Savitzky-Golay second derivatives, were explored individually and accepted as the best preprocessing method based on the highest performance in calibration and validation results. The results showed maximum validation model performance was found at 86.2% by applying the Savitzky-Golay second derivatives preprocessing method for multiclass and 89.4% for binary class. The most important wavelength information was evaluated from the beta coefficient developed using the same preprocessing method. Finally, chemical images were generated using a best-performer model to identify the soybean plants from weeds. The generated images showed a significant difference in chemical composition between soybean and weed plants at 443 nm, 633 nm, 743 nm, and 968 nm. The correlation between these peaks and the chemical components of the plants involves α-carotenoid, chlorophyll, and moisture, respectively. This study shows promising results for the application of HSI in weed control systems for soybeans and relevant weed identification in precision agriculture applications. [ABSTRACT FROM AUTHOR]

Simple Summary: Crapemyrtle bark scale (CMBS; Acanthococcus lagerstroemiae), an invasive polyphagous sap feeder in the United States, has spread across 16 U.S. states in less than two decades, posing potential risks to the Green Industry. Confirming the host range is crucial for effective pest management of invasive insects. However, host range confirmation relying on greenhouse or field trials is often inefficient and time-consuming. In this study, we used the electrical penetration graph (EPG) to monitor the stylet penetration of CMBS in plant tissue in real-time. An R programming-based application was developed to better characterize the insect EPG waveforms recorded by EPG. By analyzing EPG-based EPG parameters, we demonstrated that CMBS has difficulty accessing the phloem tissue (salivation and ingestion) of a resistant plant compared to a susceptible plant. Importantly, we hereby present CMBS typical feeding behaviors on susceptible and non-susceptible plants comparatively, which provides direct evidence for revealing unknown hosts rapidly. Host range confirmation of invasive hemipterans relies on the evaluation of plant susceptibility though greenhouse or field trials, which are inefficient and time-consuming. When the green industry faces the fast-spreading threat of invasive pests such as crapemyrtle bark scale (Acanthococcus lagerstroemiae), it is imperative to timely identify potential host plants and evaluate plant resistance/susceptibility to pest infestation. In this study, we developed an alternative technology to complement the conventional host confirmation methods. We used electrical penetration graph (EPG) based technology to monitor the A. lagerstroemiae stylet-tip position when it was probing in different plant tissues in real-time. The frequency and relative amplitude of insect EPG waveforms were extracted by an R programming-based software written to generate eleven EPG parameters for comparative analysis between plant species. The results demonstrated that the occurrences of phloem phase and xylem phase offered conclusive evidence for host plant evaluation. Furthermore, parameters including the percentage of insects capable of accessing phloem tissue, time duration spent on initiating phloem phase and ingesting phloem sap, provided insight into why host plant susceptibility differs among similar plant species. In summary, this study developed a novel real-time diagnostic tool for quick A. lagerstroemiae host confirmation, which laid the essential foundation for effective pest management. [ABSTRACT FROM AUTHOR]

Since 2013 Melanaphis sacchari (Zehnter) (Hemiptera: Aphididae), the sugarcane aphid, has been a threat to sorghum production in the United States. The development of resistant sorghum hybrids has been one of the main management strategies. However, plant resistance can be overcome over time and new resistance genes need to be identified and introduced into adapted sorghum hybrids to secure sorghum production. Sorghum plant introduction (PI) genotypes were screened for resistance to M. sacchari through laboratory, greenhouse, and field assays. In addition, the feeding parameters of M. saccahri were analyzed and detailed in seven sorghum genotypes through EPG assays. Results showed sorghum genotypes PI 524770, PI 564163, and PI 643515 expressed resistance to M. sacchari consistently in laboratory, greenhouse, and field tests. EPG analysis suggested sorghum genotypes PI 524770 and PI 564163 express antibiosis to M. sacchari while PI 643515 expresses both antibiosis and antixenosis. Increasing the number of sorghum hybrids resistant to M. sacchari is key to improving integrated pest management of M. sacchari. By utilizing host plant resistance, sorghum producers can decrease insecticide applications while enhancing biological control. [ABSTRACT FROM AUTHOR]

Operational cost of producing lettuce (Lactuca sativa) during the winter in greenhouses is high in the northern regions of the United States due to the addition of supplemental lighting (SL) and heating. Crop productivity in greenhouses should increase to offset high operational costs and maintain profits. Factors including SL composition, heating efficiency, suitability of production systems (PS), and cultivar performance can affect crop productivity. Research-based information on optimizing the above environmental- and production-related factors is limited. This information is critical for growers to make informed decisions and increase profits during winter hydroponic production.We evaluated the interactive effects of SL composition, solution temperature, PS, and cultivar treatments on lettuce shoot dry weight (SDW, g·m-2) and shoot water content (SWC, %) in a greenhouse maintained at suboptimal air temperature (13.7 8C) using a split-plot design. There were three light treatments (sunlight without SL, sunlight + narrow-spectrum SL at nighttime, and sunlight + full-spectrum SL at nighttime), two solution temperature levels [heated (18.8 8C) and unheated (13.2 8C)], two hydroponic PS [constant flood technique (CFT) and nutrient film technique (NFT)], and eight cultivars included in the study. Results indicated that 1) a narrow-spectrum SL at nighttime in combination with heated solution resulted in maximum SDW of lettuce, 2) the SDW and SWC (major determinant of economic yield) increase between the heated and unheated solution temperature treatments was higher in the CFT than in the NFT, and 3) the positive effects of using heated solution were seen mainly in the green-color cultivars. Our research identified the optimal spectral composition of nighttime SL, tested the positive effects of alternate heating methods using heated solution on plant growth under suboptimal air temperature conditions, compared the suitability of two hydroponic PS for lettuce production, and quantified yield potential of several lettuce cultivars in hydroponic production during winter. Growers can use our research findings to make informed decisions about their investment and to maximize hydroponic lettuce productivity and profits during winter. [ABSTRACT FROM AUTHOR]

Bell peppers (Capsicum annuum L.) are ranked eighth in value for vegetable production in the United States (USDA-NASS, 2019). Due to the high value of bell peppers, disorders such as blossom-end rot (BER) can cause significant losses in yield by up to 35% for growers. BER is the symptom of a calcium (Ca2+) deficiency that may occur during periods of cell expansion when the supply of Ca2+ may be lower than demand. In this study, we determined the temporal patterns of the fruit Ca2+concentration ([Ca2+]) and accumulation in three separate studies under field and greenhouse conditions. In the three experiments, [Ca2+] during fruit development showed varied patterns: it remained constant, decreased transiently during the cell expansion phase, or displayed a more gradual sustained decrease. However, in the three experiments, fruit Ca2+ accumulation increased during development as fruit size increased. In two experiments, the distal part of the fruit had lower [Ca2+] than the proximal end. However, there was no correlation between [Ca2+] in various fruit sections with BER incidence. Seeds and placental tissue had increased [Ca2+] and several other macro- and micronutrients; this spatial distribution of Ca2+ coupled with subcellular Ca2+ distribution should be explored in future studies. The temporal pattern of Ca2+ accumulation in this study suggests that fruit Ca2+ uptake continues throughout fruit development. Therefore, Ca2+ application during bloom and early fruit development may prevent or minimize Ca2+ deficiency disorders in bell pepper. [ABSTRACT FROM AUTHOR]

Empirical models describing the factors influencing the levels of computerization of the operations of nurseries and greenhouses in the United States were estimated using the data collected from a regional survey in the Southern States and two national surveys in the United States. The models measure the significant effects of the socioeconomic characteristics of managers and operational characteristics of firms to the level of computer use among nurseries and greenhouses. Results show that the socioeconomic characteristics of the participating owners and managers had exercised limited influence in the decisions involving the computerization of horticulture operations. The operational characteristics of the horticulture operations included in the surveys which have significant influences on the level of computerization included the number of workers hired, level of automation, annual gross sales, wholesale sales, years since establishment, and location. The recent Great Recession encouraged the participating firms to increase the use of computers in their operations. [ABSTRACT FROM AUTHOR]

Abstract Climates during the Paleozoic varied from greenhouse to transitional to icehouse and siliciclastic successions deposited during those times have stratigraphic architectures consistent with magnitudes and frequencies of sea-level fluctuations at the time of deposition. Three Central Appalachian Basin Paleozoic successions, the Early Cambrian Chilhowee Group, the Late Devonian Foreknobs Formation, and the Early Pennsylvanian Breathitt Group, are compared and contrasted to develop models that relate stratigraphic architectures to greenhouse, transitional and icehouse conditions existing on Earth. Within the upper portion of the Early Cambrian Chilhowee Group, the Hampton and Erwin Formations represent a succession of 2 Myr (3rd-order) sequences consisting of stacked, 40–80 kyr (5th-order), marine parasequences that record low-magnitude, high-frequency sea-level changes consistent with greenhouse conditions. The Late Devonian Foreknobs Formation consists of a series of 0.8–1.0 Myr (3rd-order) composite sequences comprised of stacked unconformity-bounded, 225 to 450 kyr (4th-order) sequences, each containing 40 to 65 kyr (5th-order), marine parasequences. The bases of the unconformity-bounded sequences are marked by erosional surfaces (regressive surfaces of marine erosion, fluvial deposits, or paleosols) indicative of sea-level drops of 10 to 45 m consistent with a transitional greenhouse to icehouse climate. The Early Pennsylvanian Breathitt Group consists of stacked, unconformity-bounded, 100 kyr (4th-order) sequences that lack parasequences. Unconformity-bounded sequences are comprised of (from bottom to top): lowstand incised valley, braided alluvial deposits; transgressive tidal estuarine deposits; and progradational, highstand deltaic deposits. Depths of incised valleys and vertical transition into estuarine facies imply sea-level changes of >50 m consistent with icehouse conditions. This study demonstrates that siliciclastic successions preserve a record of sea-level changes consistent with greenhouse, transitional, and icehouse conditions on the Paleozoic Earth. [ABSTRACT FROM AUTHOR]

The influences of plug size and plant density during conditioning of ‘Albion’ strawberry ( Fragaria x ananassa Duch.) plants were evaluated for off-season field production in New Jersey, USA. Two plug densities (168 and 336 plants m −2 , 75 cm 3 cell volume) during conditioning in a greenhouse were evaluated. Conditioning consisted of 5 weeks under LD (natural daylength supplemented with 24 h incandescent radiation) with 100 ppm N the first week and 800 ppm N once each week during last 4 weeks. Controls were kept for 5 weeks under ND (natural daylength) with 100 ppm N once each week. Following conditioning, plants were evaluated in off-season plasticulture. Larger (134 cm 3 ) plugs were conditioned at 168 plants m −2 to compare with the smaller cells (75 cm 3 ) conditioned at the same density. Inflorescence, runner and branch crown production were monitored and fruit harvested from July through September. Conditioning accelerated flowering and fruiting. New inflorescence production in July was significantly enhanced with conditioning but treatment effects on flowering did not persist. Cumulative yield through early August was enhanced by conditioning however total yield was not affected by conditioning. Conditioning had no effect on branch crown production and significantly reduced runner production. Plug production at a higher density reduced flowering but the short day response was alleviated with conditioning. Smaller plugs flowered earlier, produced more inflorescences and produced fewer runners than plants from larger plugs. Plug size and density ultimately did not affect total yield regardless of treatment. [ABSTRACT FROM AUTHOR]

Highlights: [•] Both varieties of crupina in the United States are damaged by Ramularia crupina. [•] Damage included reduction in root weight and seed yield in greenhouse tests. [•] Removal of cauline leaves had the greatest relative effect on seed yield. [•] None of 48 taxa evaluated were susceptible to Ramularia crupinae. [•] Host range determination included mixed model analysis and generation of BLUPs. [ABSTRACT FROM AUTHOR]

Poultry producers in the United States have begun using different types of bedding materials in production houses. Release into the environment of nutrients from applied poultry litter (PL) made with different bedding materials has not been investigated, and little information is available on nutrient concentrations in soils that receive broiler litter made with such materials. In this greenhouse study, two bedding materials (rice hulls and pine chips) in PL and two nutrient-immobilizing agents (gypsum and biochar) were applied to bermudagrass, and chemical and microbial contents of runoff water, soil properties, and plant growth were evaluated. Treatments with rice hull bedding material in PL had less runoff nutrient and greater soil soluble N and P compared with pine chip bedding. Gypsum and biochar both significantly reduced C, N, P, Cu, and Zn losses from the first runoff event, which were reduced by 26, 30, 37, 38, and 38% and by 25, 24, 30, 29, and 35%, respectively, but only gypsum obviously reduced these nutrients from later events. Potassium, Ca, Mg, and Mn increased by 2, 36, 11, and 9 times, respectively, and soluble P, Cu, and Fe significantly decreased by 68, 72, and 98%, respectively, in soil amended with gypsum. Rice hull PL in combination with gypsum significantly increased the growth of bermudagrass. Our results indicate that rice hull PL posed less risk for nutrient loss than pine chip PL when applied to fields and that gypsum was better than biochar for reducing runoff C, N, P, and Cu. [ABSTRACT FROM AUTHOR]

Rhizoctonia bare patch and root rot disease of wheat, caused by Rhizoctonia solani AG-8, develops as distinct patches of stunted plants and limits the yield of direct-seeded (no-till) wheat in the Pacific Northwest of the United States. At the site of a long-term cropping systems study near Ritzville, WA, a decline in Rhizoctonia patch disease was observed over an 11-year period. Bacterial communities from bulk and rhizosphere soil of plants from inside the patches, outside the patches, and recovered patches were analyzed by using pyrosequencing with primers designed for 16S rRNA. Taxa in the class Acidobacteria and the genus Gemmatimonas were found at higher frequencies in the rhizosphere of healthy plants outside the patches than in that of diseased plants from inside the patches. Dyella and Acidobacteria subgroup Gp7 were found at higher frequencies in recovered patches. Chitinophaga, Pedobacter, Oxalobacteriaceae (Duganella and Massilia), and Chyseobacterium were found at higher frequencies in the rhizosphere of diseased plants from inside the patches. For selected taxa, trends were validated by quantitative PCR (qPCR), and observed shifts of frequencies in the rhizosphere over time were duplicated in cycling experiments in the greenhouse that involved successive plantings of wheat in Rhizoctonia-inoculated soil. Chryseobacterium soldanellicola was isolated from the rhizosphere inside the patches and exhibited significant antagonism against R. solani AG-8 in vitro and in greenhouse tests. In conclusion, we identified novel bacterial taxa that respond to conditions affecting bare patch disease symptoms and that may be involved in suppression of Rhizoctonia root rot and bare batch disease. [ABSTRACT FROM AUTHOR]

Rhinoncomimus latipes is a monophagous weevil used as a biological control agent for Persicaria perfoliata in the eastern United States. Density of adult R. latipes and resulting feeding damage has been shown to be higher in the sun than in the shade. This study aimed to determine whether phototaxis, sensitivity to enhanced host cues from healthier sun-grown plants, or a combination is driving this behavior by the weevil. A series of greenhouse choice tests between various combinations of plant and light conditions showed that R. latipes is positively phototactic, responsive to host cues, and preferentially attracted to sun-grown plants over shade-grown plants. From our experiments, we hypothesize two phases of dispersal and host finding in R. latipes. The initial stage is controlled primarily by phototaxis, whereas the later stage is controlled jointly by host cues and light conditions. [ABSTRACT FROM AUTHOR]

Sudden death syndrome, caused by Fusarium virguliforme, is an important disease of soybean in the United States. Fifteen species of crops, weeds, or prairie plants were evaluated for their potential as hosts of F. virguliforme. Root and foliar symptoms and plant biomass were assessed following greenhouse inoculation studies. Root colonization of F virguliforme was determined with isolations and with polymerase chain reaction assays. Soybean, alfalfa, pinto and navy bean, white and red clover, pea, and Canadian milk vetch developed root necrosis. Soybean, alfalfa, and red clover also developed foliar symptoms following inoculation. Sugar beet and canola did not develop symptoms but had significant reductions in biomass, suggesting that they are also hosts of F. virguliforme. Corn, wheat, ryegrass, pigweed, and lambsquarters did not develop symptoms. However, these species appeared to be asymptomatic hosts because quantities of pathogen DNA detected in inoculated roots were similar to quantities detected in inoculated soybean roots. These results suggest that the number and diversity of hosts for F. virguliforme are greater than previously reported. The likely broad host range limits the efficacy of crop rotation and indicates that crops other than soybean can be damaged by F virguliforme and maintain or increase inoculum in soil. [ABSTRACT FROM AUTHOR]

Abstract: Sweetpotato (Ipomea batatas L.) ‘Whatley–Loretan’ was developed for space life support by researchers at Tuskegee University for its highly productive, nutritious storage roots. This promising candidate space life-support crop has a sprawling habit and aggressive growth rate in favorable environments that demands substantial growing area. Shoot pruning is not a viable option for vine control because removal of the main shoot apex drastically inhibits storage-root initiation and development, and chemical growth retardants typically are not cleared for use with food crops. As part of a large effort by the NASA Specialized Center of Research and Training in Advanced Life Support to reduce equivalent system mass (ESM) for food production in space, the dilemma of vine management for sweetpotato was addressed in effort to conserve growth area without compromising root yield. Root yields from unbranched vines trained spirally around wire frames configured either in the shapes of cones or cylinders were similar to those from vines trained horizontally along the bench, but occupying only a small fraction of the bench area. This finding indicates that sweetpotato is highly adaptable to a variety of vine-training architectures. Planting a second plant in the growth container and training the two vines in opposite directions around frames enhanced root yield and number, but had little effect on average length of each vine or bench area occupied. Once again, root yields were similar for both configurations of wire support frames. The 3–4-month crop-production cycles for sweetpotato in the greenhouse spanned all seasons of multiple years during the course of the study, and although electric lighting was used for photoperiod control and to supplement photosynthetic light during low-light seasons, there still were differences in total light available across seasons. Light variations and other environmental differences among experiments in the greenhouse had more effects on vine length than on root yield. Average vine length correlated positively with total hours of daylight received across seasons, and responses for one plant per container were higher above a threshold duration of solar exposure, suggesting that the vines of two plants per container compete for available light. In addition to the adaptability of sweetpotato to various vine-training architectures and across seasons in terms of maintaining root productivity, the open, interior volumes of the support frames tested in this study will provide future opportunity to enhance sweetpotato root yield in space by adding novel interior lighting, such as from intracanopy arrays of light-emitting diodes. This work was sponsored by NASA grant NAG 5 1286. [Copyright &y& Elsevier]

Stagonospora nodorum blotch (SNB), caused by Phaeosphaeria nodorum, is a destructive disease of wheat (Triticum aestivum) found throughout the United States. Host resistance is the only economically feasible option lot managing the disease; however, few SNB-resistant wheat cultivars are known to exist. In this study, we report findings from an association mapping (AM) of resistance to P nodorum in 567 spring wheat landraces of diverse geographic origin. The accessions were evaluated for seedling resistance to P. nodorum in a greenhouse. Phenotypic data and 625 polymorphic diversity array technology (DART) markers have been used for linkage disequilibrium (LD) and association analyses. The results showed that seven DArT markers on five chromosomes (2D, 3B. 5B, 6A, and 7A) were significantly associated with resistance to P. nodorum. Genetic regions on 2D, 3B. and 5B correspond to previously mapped quantitative trait loci (QTL) conferring resistance to P. nodorum whereas the remaining QTL appeared to be novel. These results demonstrate that the use of AM is an effective method for identifying new genomic regions associated with resistance to P. nodorum in spring wheat landraces. Additionally, the novel resistance found in this study could be useful in wheat breeding aimed at controlling SNB. [ABSTRACT FROM AUTHOR]

Verticillium wilt, caused by Verticillium dahliae, is a major constraint to mint (Mentha spp.) production in the United States, and the use of resistant cultivars is an important component of Verticillium wilt management. Two Mentha arvensis and four M. longifolia genotypes were evaluated for resistance to Verticillium wilt in the greenhouse using V. dahliae isolates obtained from different hosts and belonging to different vegetative compatibility groups. Isolates of V. dahliae obtained from peppermint (M. × piperita) caused significantly higher disease severity, plant mortality, and yield reduction than isolates obtained from other hosts. Disease severity, plant mortality, and pathogen incidence in aboveground stems were higher and yields lower in peppermint, the susceptible standard, compared with the resistant standard, native spearmint (M. spicata). Root-dip inoculations of M. arvensis and M. longifolia with isolates of V dahliae obtained from peppermint produced severe symptoms; however, both species displayed the ability to recover from infection and produce asymptomatic growth from rhizomes. Both M. arvensis cultivars exhibited lower mean disease severity ratings following cutback and regrowth and were not significantly different than native spearmint. The restriction of pathogen movement in aboveground tissue and ability to recover from infection may be important components of V. dahliae resistance in perennial mint cropping systems. [ABSTRACT FROM AUTHOR]

The article looks at schoolyard gardens in the U.S. which are helping children acquire better eating habits and explains how geography can be a conduit for this. It enumerates examples starting from the small butterfly garden of Watkins Elementary School in Washington, D.C., to the beds and greenhouses of the author's own local community of Ashland, Missouri, and the White House kitchen garden. The author opines that geography is the perfect tool for promoting this food revolution.

As the threat of global climate change grows increasingly dire, we are faced with the challenge of reducing carbon dioxide (CO2) (the leading greenhouse gas) emissions to the atmosphere. There is much debate about what are the most effective strategies for meeting this challenge. In this debate, one prominent question centers on whether reducing the carbon intensity of the economy (CO2 emissions per dollar of gross domestic product) will help reduce total CO2 emissions. Some argue that improvements in the carbon efficiency of the economy will allow us to reduce CO2 emissions even in the face of economic growth. Others suggest that improving carbon efficiency may not only be insufficient to counter the effects of economic growth, it may actually spur the expansion of production and consumption, and thereby lead to an escalation of CO2 emissions. Here, I address this issue by examining trends in carbon intensity and total CO2 emissions in the world as a whole and in the five nations that emit the most CO2: China, the United States, Russia, India, and Japan. I find that in recent years the carbon intensity of the world as a whole and in these major emitters has generally declined (i.e., carbon efficiency has improved), yet total emissions have generally risen. This suggests that improving efficiency is unlikely to reduce total CO2 emissions. Therefore, in order to reduce CO2 emissions it will likely be necessary to challenge the growth ideology common to the modern era and shift societies to economic systems that are not dependent on growth. [ABSTRACT FROM AUTHOR]

In recent years, the commercial greenhouse industry has begun to implement sustainable production practices. However, floriculture certification programs for sustainable production practices are a relatively new phenomenon in the United States. Between July and Oct. 2008, a commercial floriculture grower survey was conducted to determine potential barriers to sustainable floriculture certification. Using a logistic regression model, seven potential areas were evaluated: risk, profitability, economic viability, prior experience, education, operation size, and customer types. Although respondents had positive attitudes toward sustainability and had adopted sustainable practices, respondents had little knowledge and interest in U.S. certification. [ABSTRACT FROM AUTHOR]

Abstract: Twelve cored wells through the Silurian section of the Wabash Platform, Indiana, U.S.A., and 2 non-cored basinal wells with cuttings, were studied to define the sequence stratigraphy of a sediment-starved ramp within a low-latitude epeiric sea during the latest Ordovician icehouse to Silurian greenhouse transition. The Wabash Platform (approximately 200,000km2 area) was bounded to the north by the Michigan Basin, to the east by the Appalachian foreland basin, and passed to the southwest into the Vincennes Basin, which was open to the ocean. Facies developed include: platform-fringing buildups (stromatactis wackestone core, stromatoporoid skeletal wackestone caps and crinoidal rudstone/packstone flank facies); and non-buildup crinoid grainstone–packstone sheets (shoals), skeletal wackestone (variably cherty; between fair weather and storm wave base; deep lagoon and deep ramp) and carbonate mudstone (clean to argillaceous; sub-storm wave base, deep lagoon and deep ramp/basin). The eleven sequences, 2m to 30m thick and 1 to 4m.y. durations (average ∼2.5m.y.), generally can be correlated to global sea-level cycles. The lower three sequences are disconformity-bounded (reflecting moderate ice sheets) but the others are relatively conformable. The most easily mapped regional surfaces are the transgressive surfaces, because the correlative conformities are cryptic. The wide well spacing prevented mapping of lowstand system tracts. The transgressive systems tracts are upward-deepening, upward-fining carbonate units, that become more argillaceous and silty upward. The highstand systems tracts are upward-coarsening carbonate mudstone to wackestone–packstone and rare grainstone. Barrier bank complexes and isolated buildups aggraded during deposition of the upper 4 sequences to form a discontinuous raised rim (∼40m relief) to the ramp while the interior of the platform remained sediment starved. Subsidence rates in the basin were very low (0.6 to 1.2cm/k.y.), but the low platform accumulation rates (0.2cm/k.y. to 0.8cm/k.y.) prevented the seafloor from building to sea level in all but the lower three sequences and later over barrier banks (accumulation rates 2cm/k.y.). Parasequence development in high-accommodation settings elsewhere in the Silurian in North America records transition from moderate ice-sheets to an ice-free world. This is weakly expressed on the Wabash Platform due to the dominantly deeper subtidal setting. The remarkably low sedimentation rates resulted from the epeiric sea being isolated from the open ocean, and they likely are typical of the large epeiric seas of the Paleozoic. [Copyright &y& Elsevier]

In the southwestern and western Cotton Belt of the U.S. soil salinity can reduce cotton productivity and quality. This study was conducted to determine the physiological responses of six genotypes including five Upland cotton (Gossypium hirsutum L.) cultivars and one Pima cotton line (G. barbadense L.) to NaCl under greenhouse conditions. Seeds were germinated and grown for 14 days prior to salt treatment (daily 100 ml of 200 mM NaCl) for 21 days. Compared with the control (daily 100 ml tap water), the NaCl treatment significantly reduced plant height, leaf area, fresh weight, and dry weight. The NaCl stress also significantly increased leaf chlorophyll content, but did not affect leaf fluorescence. Of the six genotypes, Pima 57-4 and SG 747 had the most growth reduction, and were most sensitive to NaCl; DP 33B, JinR 422 and Acala Phy 72 had the least growth reduction and were most NaCl tolerant. Although all the six genotypes under the salt treatment had significantly higher Na and Cl accumulation in leaves, SG 747 and Pima 57-4 accumulated more Na and Cl than DP 33B. Increases in leaf N, Zn, and Mn concentrations were also observed in the NaCl-treated plants. While leaf P, Ca, and S concentrations remained unchanged overall in the genotypes tested, leaf K, Mg, Fe, and Cu concentrations significantly decreased during salt stress. Reduction in plant height is a simple, easy, sensitive, non-destructive measurement to evaluate salt tolerance in cotton. [ABSTRACT FROM AUTHOR]

Abstract: The panicle rice mite (PRM), Steneotarsonemus spinki Smiley, was reported in 2007 in the United States in greenhouses and/or field cultures of rice (Oryza sativa L.) in the states of Arkansas, Louisiana, New York, and Texas. PRM had not been reported in rice culture in the United States since the original type specimen was collected in Louisiana in association with a delphacid insect in the 1960s. PRM is the most important and destructive mite pest attacking the rice crop worldwide. It has been recognized as a pest of rice throughout the rice-growing regions of Asia since the 1970s. Historical reports of rice crop damage dating back to the 1930s also have been speculatively attributed to the PRM in India. In the late 1990s PRM was reported in Cuba, and quickly spread throughout the Caribbean and Central America. Rice crop losses of up to 90% in the Caribbean have been attributed to the PRM since first reported. The PRM attacks rice plants by feeding on the inside of the leaf sheath and developing grains. Damage associated with PRM infestations in rice includes plant sterility, partial panicle infertility, and grain malformation. However, it is difficult to characterize the damage caused solely by the PRM because the mite is commonly reported interacting with several rice plant pathogens including Sarocladium oryzae (Sawada) and Burkholderia glumae (Kurita and Tabei). The purpose of this article is to review the literature regarding the PRM in response to its re-discovery in the United States. We also summarize findings from countries where the PRM has historically been a significant pest of the rice crop. This article re-examines the taxonomic ranking of the PRM and includes a key to the USA species of Steneotarsonemus, its current distribution, damage to rice plants, its association with plant pathogens, host plant records, life history, survival under extreme temperature conditions, and current management strategies. Our hope is that this article will stimulate research on the biology and management of the PRM in the United States. [Copyright &y& Elsevier]

Problem: Solar energy has potential to solve many types of planning problems. Knowing where existing household solar energy users are located and what factors explain this distribution can help craft appropriate local policies. Purpose: This study analyzes the spatial distribution of households who heat their homes with solar energy across the contiguous United States. Methods: We use geographic information systems (GIS) and zero-inflated negative binomial statistical techniques to test three sets of geographic predictors at the scale of the county: environmental, economic, and sociopolitical. Results and conclusions: Descriptive, GIS, and regression results indicate that the expected number of households using solar energy to heat their homes increases significantly with the amount of solar radiation received, but that other environmental, socioeconomic, and political factors are also significant predictors. The number of solar households in a county is a positive function of wealth (operationalized as median home value), urbanization, and the percentage of residents in the peak period of the lifecycle-consumption curve. Having a solar energy technology provider in the county did not appear to be significant. Finally, we confirmed that households heating with solar energy increase with the percentage of persons who vote for the Democratic Party in presidential elections and with local government involvement in the International Council for Local Environmental Initiatives. Takeaway for practice: Our model can be used to enhance adoption of solar technologies by showing which localities possess most of the attributes that predict solar use, but adoption lags expectations. This can help design efficient and effective local plans and incentives calibrated to local environmental, economic, and sociopolitical conditions. Research support: Portions of the data collection for this research were supported under Award No. NA03OAR4310164 by the National Oceanic and Atmospheric Administration, U.S. Department of Commerce. The statements, findings, conclusions, and recommendations are those of the authors and do not necessarily reflect the views of the National Oceanic and Atmospheric Administration or the Department of Commerce. [ABSTRACT FROM AUTHOR]

Bromus tectorum (cheatgrass) is an invasive annual that occupies perennial grass and shrub communities throughout the western United States. Bronus tectorum exhibits an intriguing spatio-temporal pattern of invasion in low elevation ponderosa pine Pinus ponderosa/bunchgrass communities in western Montana where it forms dense rings beneath solitary pines following fire. This pattern provides a unique opportunity to investigate several indirect effects of native vegetation that influence the invasion pattern of B. tectorum, and specifically how native species, disturbance, and soil resources interact to influence the spatio-temporal pattern of invasion. We established four replicate field sites, each containing burned-tree, burned-grass, unburned-tree, and unburned-grass sampling locations, and initiated a series of field sampling and greenhouse experiments utilizing these locations. The objective of our first greenhouse experiment was to identify whether belowground factors contributed to the pattern of B. tectorum biomass observed in these field locations. This experiment generated a B. tectorum biomass response that was nearly identical to the invasion pattern observed in the field, suggesting further investigation of belowground factors was necessary. We measured resin-sorbed NH4+ and NO3− during one generation of B. tectorum, and measured a suite of P fractions through a sequential extraction procedure from these soils. These data revealed that a resource island of high N and P exists beneath pine trees. Through a second greenhouse experiment, we determined that N limited B. tectorum biomass in tree soil, whereas P limited biomass in bunchgrass soil. Finally, through a germination experiment we determined that pine litter strongly inhibited B. tectorum germination. These data suggest B. tectorum is regulated by P in bunchgrass soil, and by N and inhibition by pine litter beneath trees, effects that are likely alleviated by fire. These data demonstrate the combined role of direct and indirect interactions between native and invasive species in regulating biological invasions. [ABSTRACT FROM AUTHOR]

Some amount of shade may be optimal to produce high-quality tomatoes in a greenhouse during summer months in the northeast United States. Simultaneous comparisons were made among greenhouse sections that were either not shaded or covered with reflective aluminized shadecloth that attenuated 15%, 30%, or 50% of direct sunlight. The shadecloth was applied at the start of warm weather in June. The houses were shaded for the rest of the summer, and fruit was picked until late August. Total yield decreased linearly with increasing shade, but there was no significant difference among shade treatments in marketable yield. The fraction of fruit that was marketable was greatest for plants grown under 50% shade. This fraction was 9% greater than in a greenhouse with no shade in 2003 and 7% greater in 2004 and 2005. Cracked skin was the defect most affected by shade. Among sensitive cultivars, up to 35% of the fruit produced in greenhouses with no shade had cracked skin, whereas in greenhouses covered with 50% shade, only 24% to 26% of the tomatoes had cracked skin. There was no consistent trend for shade density in the fraction of fruit with green shoulder, blossom end rot, or irregular shape. The effect of shade increased with duration of shading. There was no effect of 50% shade compared with no shade on total yield within 20 days, but yield decreased by 20% in the interval from 25 to 45 days after shading and by 30% after 50 or more days of shading in 2005. Marketable yield only decreased after more than 45 days of shading for cultivars that were not sensitive to cracked skin or uneven ripening. Shade decreased fruit size over the entire season only in 2003. In general, shading increased the fraction of marketable tomato fruit without affecting fruit size. [ABSTRACT FROM AUTHOR]

This article discusses a study to overcome priority problems faced by the floricultural greenhouse industry in the Great Lakes region. Conducted by pathologist Jim Locke and horticulturist Jonathan Frantz of the U.S. Agricultural Research Service, the study found the top two concerns of greenhouse operators: to make sure their valuable plants are not ruined by too little or too much water and to provide them with optimal nutrients. Locke and Frantz toured greenhouses throughout northern Ohio to talk with industry people about priority problems and to observe the operations themselves.

Spinach (Spinacia oleracea L.) has one of the highest United States per capita consumption rates among leafy vegetable crops, and also ranks second for lutein and β-carotene carotenoid concentration. The objectives of this study were to determine the effects of nitrogen (N) concentration on elemental and pigment accumulation in spinach. Two spinach cultivars (‘Melody’ and ‘Springer F1’) were greenhouse grown in nutrient solution culture under N treatments of 13, 26, 52, and 105 mg L- 1. Leaf tissue biomass increased from 45.6 to 273.2 g plant- 1 and from 127.0 to 438.6 g plant- 1 as N increased from 13 to 105 mg L- 1 for ‘Springer F1’ and ‘Melody’, respectively. Leaf tissue N, phosphorus (P), calcium (Ca), magnesium (Mg), copper (Cu), and zinc (Zn) responded to N treatments. Lutein accumulations, expressed on a fresh weight basis, responded quadratically to increasing N treatments for ‘Springer F1’. Maximum lutein values were 110 and 76 μ g g- 1 on a fresh weight basis, and maximum β-carotene values were 85 and 57 μ g g- 1 on a fresh weight basis for ‘Springer F1’ and ‘Melody’, respectively. Interestingly, N levels had a significant effect on carotenoid accumulation in both ‘Springer F1’ and ‘Melody’ when the pigments were expressed on a dry weight basis. Leaf tissue lutein increased from 0.59 to 1.06 mg g- 1 and from 0.59 to 0.90 mg g- 1 on a dry weight basis with increasing N treatments for ‘Springer F1’ and ‘Melody’, respectively. Reporting lutein and β-carotene on both a fresh and dry weight basis may be the most accurate way to express the carotenoid values of spinach. [ABSTRACT FROM AUTHOR]

The article focuses on the adoption of a cluster-based approach to enable the greenhouse industry to response to competitive challenges in Ohio. The author cited the collaborative solutions to common problems of economic viability. He also described on how the clusters outlines economic development of greenhouse industry.

The purpose of this study was to characterize the behavior of black vine weevil larvae, Otiorhynchus sulcatus (F.), in the presence of two possible control options: the synthetic pyrethroid bifenthrin and the entomopathogenic fungus Metarhizium anisopliae (Metch.) Sorokin. Five third-instar black vine weevil were placed in two-choice soil olfactometers that allowed larvae to infest one of two pots. Larvae were allowed to choose between M. anisopliae (1 × 106 spores/g dry media) and untreated media, bifenthrin (25 ppm) and untreated media, as well as M. anisopliae- and bifenthrin-treated media. For all comparisons, experiments were conducted without plants in the system to test for innate responses, as well as with plants to test host-plant influence. Larvae were significantly deterred by bifenthrin without plants present in the system. No significant effect on larval preference was observed when M. anisopliae was present in media for trials without plants. M. anisopliae-treated media was preferred by black vine weevil larvae over bifenthrin without plants present in the two-choice soil olfactometer. When plants were included, a significant attraction to M. anisopliae-treated media was observed over untreated media. Unlike comparisons without plants, larvae were not repelled by bifenthrin when plants were included in the two-choice soil olfactometer. The attraction of black vine weevil larvae to pots containing plants and fungus indicates the operation of a previously undescribed tritrophic interaction. This behavior may he useful in the development of more effective biological control programs. [ABSTRACT FROM AUTHOR]

The article focuses on Michael's Bromeliads nursery managed by Michael and Donna Kiehl in Venice, Florida. A number of bromeliad varieties is available by mail order from the nursery. A new 11,000 square foot greenhouse has been completed to keep up with the demand. The nursery will be selling its bromeliads for the first time at the World Conference in San Diego, California.

After several years of development based on the requirements set by the Kyoto Protocol as well as on the experiences from emission trading regimes for hazardous gases in the USA. Two different schemes for greenhouse gas emissions trading are considered to deliver a suitable approach for emissions trading after several years of development based on the requirements set by Both systems enable private entities to generate and sell tradable allowances or credits by the introduction of more efficient technology.

Assesses the relative phytoavailability of phosphorus in biosolids representative of residuals produced nationally in the U.S. Greenhouse study of pasture grass grown in phosphorus-deficient soils amended with biosolids and a commercial fertilizer; Biological phosphorus removal process; Plant tissue analysis.

Three populations of the leafminer, Liriomyza trifolii (Burgess), were collected from commercial ornamental production greenhouses in the United States and tested for susceptibility to three commercial insecticides. A leaf dip bioassay of leaves containing young (1-2-d-old) larvae was used. Based on larval mortality and compared with a susceptible laboratory reference colony, the three strains varied in spectrum and level of resistance to the insecticides. CA-1, collected from Gerbera daisy, was moderately resistant to cyromazine (18.1-fold) and abamectin (22.0-fold), but highly resistant to spinosad (>188-fold). CA-2, collected from chrysanthemums, was not resistant to abamectin, had a low level of resistance to cyromazine (8.2-fold), but was extremely resistant to spinosad (1,102-fold). GA-1, collected from chrysanthemums, had very low levels of resistance to cyromazine (5.4-fold) and spinosad (1.9-fold) but was moderately resistant to abamectin (30.6-fold). When reared in the absence of insecticide selection pressure, all three strains reverted to approximately the level of the reference strain. The CA-1 strain reverted in nine generations to cyromazine; however, the lowest levels of abamectin and spinosad resistance reverted to was 3.1-fold at F8 and 3.2 at the F10, respectively. The CA-2 strain reverted in five generations to both cyromazine and spinosad. GA-1 reverted in five generations to abamectin. Based on the results, resistance to these three insecticides was unstable. Additionally, there was no cross-resistance among these three insecticides. [ABSTRACT FROM AUTHOR]

Focuses on the chilling requirements for seed germination of perennial wild buckwheat in Utah. Generation of greenhouse-propagated from seeds; Consideration of the plant as a drought-tolerant ornamentals; Assessment of the unknown dormancy status.