Greenhouse engineering: New technologies and approaches

Firstly, this article discusses the greenhouse engineering situation in three geographic areas which are relevant in the field of protected cultivation: Northern Asia, The Netherlands and the Mediterranean. For each area, the prevailing greenhouse type and equipment is briefly described. Secondly, the main technological constraints are pointed out and finally the research directions are discussed. For all areas under consideration, attempts to design more efficient greenhouse systems are under way. In Northern Asia progress is being made towards the optimisation of greenhouses as a solar collector and to the development of new heating strategies. Important subjects addressed in The Netherlands are energy conservation and the replacement or alleviation of human labour by increasing mechanisation. In the Mediterranean there is growing interest in semi-closed greenhouses with CO2 enrichment and control of excessive humidity. All geographic areas share the need of having an optimised climate control based on the crop response to the greenhouse environment. All areas also share the requirement of being respectful to the environment, therefore future greenhouses are expected to use engineering to produce with minimal or zero emissions

Growth and Flowering of Cymbidium Red Fire and Yokihi in Response to Light Intensity, Temperature and Nitrogen Nutrition during Night Interruption Forcing Culture

학위논문 (박사)-- 서울대학교 대학원 : 식물생산과학부 원예과학 전공, 2012. 8. 김기선.The effects of night interruption (NI) with different light intensities, temperature and nitrogen nutrient control were examined on vegetative and reproductive growth of Cymbidium Red Fire and Yokihi. The cymbidium cultivars were grown under 9/15 h ambient light/dark (control), 9 h ambient light plus NI (22:00 to 02:00 h) with low light intensity at 3-7 mol m2 s1 (LNI) or 9 h ambient light plus NI with high light intensity at 120 mol m2 s1 (HNI) conditions. While none of the control plants flowered within 2 years, 100% of the Yokihi and 80% of the Red Fire plants grown under the HNI condition flowered. In the LNI group, 60% of the plants in both cultivars flowered. Plants in the HNI group showed a decreased time to visible inflorescence and flowering than those in the LNI group. Changes of carbohydrates including sucrose, fructose, glucose and starch were evaluated to determine the factors involved in flowering promotion in Cymbidium Red Fire during a NI forcing culture. Plants grown in the LNI and HNI had more leaves and pseudobulbs dry mass than those grown in the control group. Soluble carbohydrate concentrations in the pseudobulbs of the plants were greater in the HNI than in the LNI and control. Glucose was the most abundant soluble carbohydrate. Starch was present in the leaf exudate and was greater in the plants in the LNI than in the HNI or control. The growth and flowering of Cymbidium Red Fire and Yokihi plants were tried to improve flowering percentage during NI forcing culture with summer cooling. The greenhouses where the plants were grown were cooled by a mist system (mist) or a shade screen (shade). The temperature was approximately 2°C lower in the mist than in the shade and the relative humidity under the mist and shade condition were 80 ± 5% and 55 ± 5%, respectively. The plants that received NI followed by the mist flowered within 2 years with different flowering percentages depending on light intensity, while none of the plants flowered with the shade condition. Photosynthetic characteristics of Cymbidium Red Fire and Yokihi were investigated when the plants were exposed to NI forcing culture in relation to leaf nitrogen content. Photoinhibition could occur when NI applied to Cymbidium without supplemental nitrogen. The results of this study provide information on promotion of Cymbidium cultivation for high value cultivars. Application of the NI improved the flower quality of Cymbidium by decreasing days to flower. The NI promoted Cymbidium flowering within 2 years. Temperature should be maintained under 27°C by a mist system in a greenhouse cultivation to avoid heat stress and inflorescence abortion during summer growing seasons. Additional nitrogen should be fertilized when the NI is introduced in the forcing culture. The developed cultivation methods are beneficial to promote flowering and to enhance flower quality of Cymbidium Red Fire and Yokihi.ABSTRACT i CONTENTS iv LIST OF TABLES vii LIST OF FIGURES viii GENERAL INTRODUCTION 1 LITERATURE REVIEW 4 Control of Flowering in Orchids 4 Physiology of Cymbidium 6 Flowering Responses to NI 7 LITERATURE CITED 9 CHAPTER I. Night Interruption Promotes Vegetative Growth and Flowering of Cymbidium Red Fire and Yokihi ABSTRACT 13 INTRODUCTION 15 MATERIALS AND METHODS 18 RESULTS 22 DISCUSSION 32 LITERATURE CITED 36 CHAPTER II. Carbohydrate Changes of Cymbidium Red Fire in Response to Night Interruption with Different Light Intensities ABSTRACT 39 INTRODUCTION 41 MATERIALS AND METHODS 44 RESULTS 48 DISCUSSION 57 LITERATURE CITED 60 CHAPTER III. Growth and Flowering of Cymbidium Red Fire and Yokihi during Night Interruption Forcing Culture with Mist and Shade Systems ABSTRACT 63 INTRODUCTION 65 MATERIALS AND METHODS 68 RESULTS 73 DISCUSSION 83 LITERATURE CITED 86 CHAPTER IV. Photosynthetic Characteristics of Cymbidium Red Fire and Yokihi in Response to Night Interruption and Nitrogen Nutrition ABSTRACT 89 INTRODUCTION 91 MATERIALS AND METHODS 93 RESULTS 99 DISCUSSION 114 LITERATURE CITED 119 CONCLUSION 124 ABSTRACT IN KOREAN 126Docto

Missouri Botanical Garden bulletin.

v.46 (1958

Plantsman, Jun/Jul 1993

A newsletter of the New Hampshire Plant Growers\u27 Associatio

Missouri Botanical Garden bulletin.

v.56 (1968

Green Roofs in the Garden City: Exploring the Opportunities for Green Roof Policies in Missoula, Montana

Global climate change is expected to have adverse impacts on the Rocky Mountain West, including impacts on water and land use, energy consumption, weather patterns, and wildlife stewardship. The State of Montana, Missoula County and the City of Missoula all have recognized these threats and are taking steps to address climate change impacts. In response to the unique challenges posed by urban environments, the practice of green, or vegetative, roofing has been promoted through policy measures by a number of cities in the United States and abroad. This project explores green roofing and the policies used to encourage the practice with the goal of recommending what kind of green roof policy, if any, would be politically and practically feasible in the City of Missoula. This project explores the practice of green roofing through a discussion of its history and the benefits green roofs offer to building owners and communities. It explores three obstacles to widespread green roof adoption. It introduces the six main green roof policy tools identified through research, and presents eight case examples of cities with green roof policies in place to gain an understanding of these programs’ goals, the policy measures employed, and how successful these policies have been. It presents interview data from fourteen interviews with twenty-two Missoula-area stakeholders from four stakeholder groups: City administrators, architecture, design and building organizations, the conservation community, and others. These groups are analyzed to determine whether they support the City of Missoula taking policy steps to encourage green roofing, and to determine these groups’ preferred policy tools. Based on this research, the project concludes with six recommendations as to how the City of Missoula can best promote the practice of green roofing: educating residents and building owners; pursuing a City-lead green roof demonstration project; establishing standards for green roofs in the Missoula Building Code; passing a nonbinding resolution in favor of green roofing; committing to a strong sustainable building policy for City buildings; and offering nonmonetary incentives for green roof installation

Light-emitting diodes as an alternative supplemental lighting source for greenhouse tomato propagation and production

Intensive year-round local production of greenhouse-grown tomatoes (Solanum lycopersicum L.) requires the use of supplemental lighting (SL) to complement solar radiation in light-limited seasonal climates. However, SL represents a large expense to greenhouse-vegetable production. Currently, energy is second only to labor as the most expensive indirect cost of production. Thus, the greenhouse industry is interested in cost-effective, energy-efficient sources of supplemental photosynthetic light to sustain steady supplies of high-quality produce during the off-season. Overhead (OH) high-pressure sodium (HPS) lamps are considered the industry standard in greenhouse SL because of their capability to deliver adequate photosynthetically active radiation (PAR) to crops. However, HPS lamps are inefficient consumers of electrical energy with a high life-cycle cost, an intense environmental impact, and an orange-biased, blue-deficient emission spectrum. Light-emitting diodes (LEDs) offer an exciting opportunity to improve energy efficiency in greenhouse lighting because their relatively low surface temperature allows them to operate in close proximity to plant tissue without overheating or scorching plants, thereby increasing availablePAR at leaf level using less input power than HPS lamps. In addition, unlike traditional light sources used in commercial greenhouses today, LEDs are solid state, robust, long-lasting, and can be designed to emit narrow-band wavelengths that can be selected to maximize photosynthesis and growth for specific crops. ^ The goal of our research is to enable U.S. greenhouse growers to transition from HPS lighting to LED technologies for supplemental photosynthetic lighting. The specific objective of this research was to evaluate LEDs as alternative SL sources for greenhouse tomato propagation and production. Three research goals were established to support my objective: 1) to compare seasonal growth responses to three red:blue ratios of LED SL vs. HPS SL vs. ambient light for the propagation of six tomato cultivars; 2) quantify plant growth, yield, and energy consumption using intracanopy lighting (ICL) with LEDs (ICL-LED) or OH-HPS lamps as different SL sources and positions for high-wire greenhouse tomato production; 3) compare crop physiological responses to different SL sources and positions [ICL-LED vs. OH-HPS vs. hybrid lighting (ICL-LED + OH-HPS)] within an indeterminate high-wire tomato canopy. ^ Supplemental lighting increased hypocotyl diameter, epicotyl length, shoot dry weight, leaf number, and leaf expansion relative to control, whereas hypocotyl elongation decreased when SL was applied. For all cultivars tested, the combination of red and blue in SL typically increased growth of tomato seedlings. Our results indicate that blue light in SL has potential to increase overall seedling growth compared to blue-deficient LED SL treatments in overcast, variable-DLI climates. Further production studies showed that the ICL-LED technology supports similar growth and yield compared to OH-HPS but at lower electrical costs (from SL only). Additionally, we found that CO2 assimilation measured under ambient environmental conditions (A), photosynthetic quantum yield (&thetas;), maximum gross CO2 assimilation (Amax) and the light-saturation point of photosynthesis were good indicators of how ICL diminishes the top-to-bottom decline in photosynthetic activity that typically occurs with OH SL. However, we did not find any yield differences among SL treatments, indicating that higher source activity from ICL does not necessarily lead to yield increases. Based on the lower energy consumption measured for ICL-LED, and, to a lesser extent, for hybrid SL, compared to OH-HPS, we concluded that replacing OH-HPS lamps with ICL-LED or hybrid SL has great potential for energy savings during high-wire greenhouse tomato production. However, our results showed that higher total canopy photosynthesis did not lead to higher yields, most likely due to a redistribution of photoassimilate partitioning to non-harvested, vegetative plant parts