Greenhouse Space Research Articles

Dependence of greenhouse tunnel ventilation on wind direction and crop height

Greenhouse ventilation depends on parameters such as internal and external climates and the design of the greenhouse and its vents. These have been intensively studied and results incorporated into various general ventilation models in the past. However, ventilation also greatly depends on the characteristics of the crop occupying the greenhouse space, especially with tall crops such as tomatoes. The effect of the crop is particularly great for greenhouse tunnels, whose side openings may be partly obstructed by the crop rows. In the past very few studies have been made of this crucial question. To address the issue, the relationship between ventilation of a tunnel type greenhouse and the characteristics of the tomato crop growing in it was systematically studied. The greenhouse tunnel's natural ventilation was studied experimentally, using the tracer gas method, for three main stages of the tomato crop: (i) with small plants; (ii) with a young tomato crop 1 m high; (iii) with a mature tomato crop 2.13 m high. The dependence of ventilation efficiency in the greenhouse tunnel on crop height, leaf area index and wind direction was assessed and numerical relations deduced.

2008년 우리나라 주요 작물 바이러스병 발생 상황

Viruses diagnosed on crops including rice plants from farmers or agricultural extension agencies cover the country were 11 species including Broad bean wilt virus 2 (BBWV2) in 2008. Tomato spotted wilt virus (TSWV) was the most important virus having the detection rate of 22.9%. Two viruses of Tomato yellow leaf curl virus (TYLCV) and Tobacco leaf curl virus (TLCV) inducing leaf yellow and curl diseases on tomatoes were occurred newly with the detection rate of 12.2% and 4.0%, respectively, in 2008. Rice stripe virus (RSV) was occurred on 869.5 ha mainly at Jindo and Haenam areas in Jeollanamdo province. At Jindo area, 12 plots were damaged severely with the infected hill rate of 83.8%. At the main production area of oriental melon at Seongju, almost all fruits from whole sale market at Seongju were infected with Cucumber green mottle mosaic virus (CGMMV) as the detection rate of 87%. The areas occurred TSWV in Korea were 25 totally from 2003 including 7 areas newly reported in 2008 including Naju in Jeoallanamdo. TSWV could be reduced as 0.1 % from 5.3% by covering insect proof net in vinyl house after chemical soil sterilization. Tomato yellow leaf curl disease was occurred on April in 2008 at Tongyoung area in Kyeongsangnamdo, and detected continuously at 13 areas, 7 in Kyeongsangnamdo, 4 in Jeollabukdo and 2 in Jejudo. Potato spindle tuber viroid (PSTVd) was occurred abruptly in a confined space of a civil breeding greenhouse and a cultivar evaluation field followed by disuse 17.4 M/T of potato tubers. No PSTVd was detected at 17 fields cultivated the related potatoes to the bred company by RT-PCR.

Airflow and microclimate patterns in a one-hectare Canary type greenhouse: An experimental and CFD assisted study

This study presents an analysis of air circulation and microclimate distribution during daytime in a 1-ha Canary type tomato greenhouse in the coastal area of southern Morocco. The investigation of the climate inside the greenhouse is based on a numerical simulation using a finite volumes method to solve the mass, momentum and energy conservation equations. The main novelty of this simulation lies in the realism of the 3D modelling of this very large agricultural structure with (i) a coupling of convective and radiative exchanges at the surface of the plastic roof cover, (ii) simulation of the dynamic influence of the insect screens and tomato crop on airflow movement, using the concept of porous medium, (iii) simulation, in each grid cell of the crop canopy, of the sensible and latent heat exchanges between the greenhouse air and the tomato crop, and (iv) detailed simulation of climate parameters in a 1-ha real-scale commercial greenhouse. The model simulations were first validated with respect to temperature and relative humidity fields measured inside the experimental greenhouse for fairly steady-state outside conditions marked by a prevailing sea breeze around the solar noon. A good agreement was observed between the measured and simulated values for inside air temperatures and specific humidity. It was next used for exploring the details of the inside air temperature and humidity fields and plant microclimates and transpiration fluxes throughout the greenhouse space. Simulation for a wind direction perpendicular to the side and roof openings shows that the insect screen significantly reduced inside air velocity and increased inside temperature and humidity, especially in the vicinity of the crop canopy. It revealed the details of the flow field within the greenhouse. At the windward end of the greenhouse, the flow field was marked by a strong windwise air current above the tomato canopy which was fed by the windward side vent, and a slow air stream flowing within the tomato canopy space. Then, from the first third of the greenhouse to the leeward end, the flow field was marked by the combination of wind and buoyancy forces, with warmer and more humid inside air which was evacuated through the upper roof vents, while colder and dryer air was penetrated through the upper roof vent openings. Based on these simulations, design studies of the greenhouse crop system were performed to improve inside air temperature and humidity conditions by simple modifications of orientation of the crop rows.

Growing sunflower plants from seed to seed in small pots in greenhouse

This paper reports the results of two experiments in which sunflower plants were grown from seed to seed in small pots to utilize greenhouse space efficiently. We used small plastic pots (9.0 × 8.6 × 9.0 cm) filled with approximately half a liter of potting soil in a temperature-controlled greenhouse with a light : dark cycle of 14 : 10 h. In the first experiment, 100 F2:5 plants were grown on a two-square-meter bench in the greenhouse during the winter of 2007. Ninety-eight of the 100 plants survived to maturity and produced an average of 62 viable seeds with a range of 36 to 102 seeds per plant. In comparison to the plants grown in six-liter pots, we observed that all the plants grown in the small pots had a significant decrease in plant size such as height, head diameter, and number of seeds per plant. The plants grown in the small pots flowered on average 9 days later than those in the large pots. No significant difference was observed for germination rate between the seeds harvested from small and large pots. In the second experiment, two oilseed and two confectionery sunflower inbred lines were grown during the summer of 2007 to confirm the observations from the first experiment. The results were essentially the same as those observed in the first experiment. For number of seed produced per plant, an average of 13.0 to 42.2 seeds were obtained per head for each of the four lines grown in small pots, with no significant difference observed between oil and confectionery sunflower. Thus, our results suggest that it is possible to produce viable seeds from plants grown in small pots. This method should be useful for efficient line advancement in the greenhouse for breeding and genetic studies.

The study of the genetic effects in generation of pea plants cultivated during the whole cycle of ontogenesis on the board of RS ISS

Results of studies on growth and development of offspring of two genetically marked dwarf pea lines planted during the whole ontogenesis cycle in the Lada space greenhouse on board of Russian Segment of International Space Station (RS ISS) are presented. The offspring of M1 and M2 plants grown from seeds formed during space flight was examined under conditions of Earth-based. Cultivation. It had been shown that growth and developmental characteristics, frequency of chromosome aberrations in primary root meristem and level of molecular polymorphism revealed in individual plants via RAPD method show no significant differences between offspring of "space-grown" and control seeds.

Spaceflight effects on consecutive generations of peas grown onboard the Russian segment of the International Space Station

In the period from March 2003 to April 2005 we fulfilled five experimental cultivations of genetically marked dwarf pea species in greenhouse Lada installed in the Russian segment (RS) of the International Space Station (ISS). The purpose of this series of experiments was to make morphologic and genetic analysis of pea plants grown in successive generations. According to our results, pea growth and development over the full cycle of ontogenesis (from seed to seed) taking place in space greenhouse Lada were not different as compared with the ground control plants. In addition, four successive pea crops gathered in space flight did not loose their reproductive functions and formed viable seeds. Genetic analysis of the plants grown from the “space” and “ground” seeds produced by the first to fourth successive crops was performed using the methods of chromosomal aberrations count and Random Amplified Polymorphic DNA (molecular method). No genetic polymorphism was found either in the experimental or control crops. This can serve as a sound argument for the supposition that the genetic apparatus of plants is not impacted by exposure of several successive generations to the conditions of space flight.

Note: Containment ofCucumber fruit mottle mosaic virus (CFMMV) infection through roots by planting into a virus-free intermediating medium

Transfer of cucumber plants (Cucumis sativus L.) from Speedling-type polystyrene trays or polystyrene trays with a vacuum-forming insert, into pots filled with perlite infested withCucumber fruit mottle mosaic virus (CFMMV), resulted in high disease incidence. However, when the plants were removed from the trays into condensed peat cells or into perlite sleeves, prior to their introduction into the infested medium, infection by the virus was completely prevented. Our results strongly support the hypothesis that tobamovirus invasion into the root cells isvia wounds inflicted through the disturbance of the root system during transplanting. Unwounded, newly formed roots that penetrated into the infested medium did not allow invasion by the virus. The use of condensed peat trays as well as perlite sleeves can serve as an efficient means to block soilborne epidemics of tobamoviruses in infested soils. However, this practice should be combined with sanitation of the greenhouse space to eliminate virus transmissionvia the aboveground parts of the plants.

The Virginia Commercial Greenhouse Industry—Current Practices and Future Needs Assessment

This report summarizes responses to a survey of Virginia's commercial greenhouse industry, conducted in 2000-01. The survey included questions about interests and needs of growers to assist Virginia Tech Horticulture faculty and staff in planning educational and research programming. Respondents were asked about current cultural practices, future plans for automation and technology, and impact of issues facing the greenhouse industry such as regulations and labor. The 273 responses were categorized based on the amount of heated greenhouse space: small, medium, large, or other (including part-time). Following analysis of the responses, focus groups were conducted across Virginia to further discuss issues raised in the survey.

Developing a vitamin greenhouse for the life support system of the international space station and for future interplanetary missions

In order to evaluate the effects of gravity on growing plants, we conducted ground based long-term experiments with dwarf wheat, cultivar Apogee and Chinese cabbage, cultivar Khibinskaya. The test crops had been grown in overhead position with HPS lamp below root module so gravity and light intensity gradients had been in opposite direction. Plants of the control crop grew in normal position under the same lamp. Both crops were grown on porous metallic membranes with stable −1 kPa matric potential on their surface. Results from these and other studies allowed us to examine the differences in growth and development of the plants as well as the root systems in relation to the value of the gravity force influence. Dry weight of the roots from test group was decreased in 2.5 times for wheat and in 6 times – at the Chinese cabbage, but shoot dry biomass was practically same for both test and control versions. A harvest index of the test plants increased substantially. The data shows, that development of the plants was essentially changed in microgravity. The experiments in the space greenhouse Svet aboard the Mir space station proved that it is possible to compensate the effects of weightlessness on higher plants by manipulating gradients of environmental parameters (i.e. photon flux, matric potential in the root zone, etc.). However, the average productivity of Svet concerning salad crops even in ground studies did not provide more than 14 g fresh biomass per day. This does not provide a sufficient level of supplemental nutrients to the crew of the ISS. A cylindrical design of a space plant growth chamber (SPGC) allows for maximal productivity in presence of very tight energy and volume limitations onboard the ISS and provides a number of operational advantages. Productivity from this type of SPGF with a 0.5 kW energy utilization when salad growing would provide approximately 100 g of edible biomass per day, which would almost satisfy requirements for a crew of two in vitamin C and carotene and partly vitamin B group as well as rough fiber.

A synchronous rearing method for the Asian citrus psyllid and its parasitoids in quarantine

The Asian citrus psyllid, Diaphorina citri Kuwayama, and two of its parasitoids, Tamarixia radiata (Waterston) [Hymenoptera: Eulophidae] and Diaphorencyrtus aligarhensis (Shafee, Alam and Agarwal) [Hymenoptera: Encyrtidae], were reared under artificial light in a quarantine facility as part of a classical biological control program. Diaphorina citri, the vector of citrus greening disease, were reared on propagated orange jasmine (Murraya paniculata (L.) Jack) because it is not considered a host of the greening pathogen Liberobacter asiaticum and is more resistant to psyllid feeding damage than citrus. Each month, approximately 36,000 D. citri nymphs could be generated, yielding 6750 T. radiata and 1630 D. aligarhensis after 180 h of labor, and use of 150 M. paniculata plants, 20 m 2 of greenhouse space, and 18 m 2 of quarantine space. The developmental time from psyllid egg to the start of parasitoid emergence was 24 days for T. radiata and 28 days for D. aligarhensis. The sex ratio of laboratory-reared T. radiata was 1.8 $:1# (n ¼ 400) in the Taiwanese population and 2.0 $:1# (n ¼ 400) in the Vietnamese population. Both T. radiata and D. aligarhensis are long lived and could be stored for up to 30 days at 17C prior to field release, incurring less than 5% mortality. Ten percent of T. radiata (14 of 136 tested) and 10% of D. aligarhensis (22 of 209 tested) survived for 50 days when stored at 25C. Only females were observed from the population of D. aligarhensis obtained from Taiwan. 2003 Elsevier Inc. All rights reserved.

Mechanistic approach to phytoremediation of water

Conventional thinking regarding the use of food crops to clean aquaculture effluents has been that plants cannot remove nutrients in water to low levels without a reduction in productivity and quality. Because greenhouse space is expensive, productivity is critical for a profitable operation. A production strategy, called the conveyor production system (CPS), was developed using thin-film technology for plant production in dilute aquaculture effluents. With the CPS, young plants were positioned near the solution inlet in a gutter receiving the effluent and moved progressively, like along a conveyor belt, towards the outlet as they grew. Luxury consumption by lettuce plants (Lactuca sativa L. cv. Ostinata) enabled them to store P in their tissues early in their growth cycle for use later as water P levels decreased and influx could no longer meet current demands. If water is distributed in a horizontal plug-flow pattern, without the CPS, all nutrients will be luxury consumed at the inlet, making nutrients limiting at the outlet and significant greenhouse space will be dedicated to growing plants that have no market value. The object of this study was to construct and operate a pilot-scale CPS, collect data demonstrating its potential to clean effluent and produce a marketable product, and develop a mechanistic model describing the process. Greenhouse studies demonstrated that by using the CPS, phosphorus could be reduced from 0.52 to <0.01 mg l−1 by lettuce without an apparent reduction in production or quality. The mechanistic model described in this paper simulated experimental data collected during the operation of the CPS growing lettuce and defines critical data necessary for the general comparison of effluents for treatment.

Within-plant distribution of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), on ivy geranium: development of a presence-absence sampling plan.

The twospotted spider mite, Tetranychus urticae Koch, is an important pest of ivy geranium and other ornamental plants. As a part of our long-term goal to develop an integrated crop management program for ivy geraniums, the focus of this study was to produce a reliable sampling method for T. urticae on this bedding plant. Within-plant mite distribution data from a greenhouse experiment were used to identify the young-fully-opened leaf as the sampling unit. We found that 53% of the mites on a plant are on the young-fully-opened leaves. On average 22, 37, and 41% of the leaves belonged to the young, young-fully-opened, and old leaf categories, respectively. We then developed a presence-absence sampling method for T. urticae in ivy geranium using generic Taylor's coefficients for this pest. We found the optimal binomial sample sizes for estimating populations of T. urticae at densities of between 0 and 3 mites/leaf to be quite large; therefore, we recommend the use of numerical sampling within this range of T. urticae densities. We also suggest that population estimates of T. urticae on ivy geranium be done based on mite density/unit area of greenhouse space, both for conventional greenhouse pest management, and for determining how many phytoseid predators to release when using biological control.

Profile of the Virginia Commercial Greenhouse Industry

A survey was conducted in 2000-01 to provide a comprehensive description of Virginia's commercial greenhouse industry. A total of 274 responses were analyzed. Responses were categorized based on the amount of heated greenhouse space: small, medium, large, or other (including part-time). The survey included questions about growing space, number of employees, education and experience of respondent, crops grown, gross receipts, and target markets. Seventy-five percent of the respondents were owners or owners/growers and respondents reported an average of 15 years experience. Most greenhouse operations were classified as small or less than 10,000 ft2 (929.0 m2). A wide variety of crops were reported, with more than 50% growing bedding plants and nearly 50% growing herbaceous perennials in the greenhouse. Market outlets were about equally divided between wholesale and retail.

Modified Rapid DNA Extraction Protocol for High Throughput Microsatellite Analysis in Wheat

ABSTRACTNew technology is allowing marker‐assisted selection to fulfill the promise of increasing efficiency of cultivar development. However, these techniques depend upon the ability to extract DNA from large populations of plants. The objective of this project was to develop a high‐throughput DNA extraction procedure without the need for greenhouse space or growing wheat (Triticum aestivum L.) plants. A sodium hydroxide rapid DNA extraction was modified for a 96‐well format to reduce costs. Seeds were germinated in 8‐well tissue culture plates, and 4‐d‐old seedling tissue was used to extract DNA by means of sodium hydroxide methodology. Approximately 1 μg of genomic DNA per 10 mg of tissue was isolated at a cost of about $0.10. The DNA quality was verified by amplification of microsatellite markers. Results were consistent with either fresh or stored tissue extracts. This technique allows one person to extract nearly 1000 storage‐stable DNA samples daily, while keeping costs at a minimum.

Adaptive environmental control for optimal results during plant microgravity experiments

The SVET Space Greenhouse (SG) - the first and the only automated plant growth facility onboard the MIR Space Station in the period 1990–2000 was developed on a Russian-Bulgarian Project in the 80s. The aim was to study plant growth under microgravity in order to include plants as a link of future Biological Life Support Systems for the long-term manned space missions. An American developed Gas Exchange Measurement System (GEMS) was added to the existing SVET SG equipment in 1995 to monitor more environmental and physiological parameters. A lot of long-duration plant flight experiments were carried out in the SVET+GEMS. They led to significant results in the Fundamental Gravitational Biology field - second-generation wheat seeds were produced in the conditions of microgravity. The new International Space Station (ISS) will provide a perfect opportunity for conducting full life cycle plant experiments in microgravity, including measurement of more vital plant parameters, during the next 15–20 years. Nowadays plant growth facilities for scientific research based on the SVET SG functional principles are developed for the ISS by different countries (Russia, USA, Italy, Japan, etc.). A new Concept for an advanced SVET-3 Space Greenhouse for the ISS, based on the Bulgarian experience and “know-how” is described. The absolute and differential plant chamber air parameters and some plant physiological parameters are measured and processed in real time. Using the transpiration and photosynthesis measurement data the Control Unit evaluates the plant status and performs adaptive environmental control in order to provide the most favorable conditions for plant growth at every stage of plant development in experiments. A conceptual block-diagram of the SVET-3 SG is presented.

MICROGRAVITY EFFECTS ON WATER SUPPLY AND SUBSTRATE PROPERTIES IN POROUS MATRIX ROOT SUPPORT SYSTEMS

The control of water content and water movement in granular substrate-based plant root systems in microgravity is a complex problem. Improper water and oxygen delivery to plant roots has delayed studies of the effects of microgravity on plant development and the use of plants in physical and mental life support systems. Our international effort (USA, Russia and Bulgaria) has upgraded the plant growth facilities on the Mir Orbital Station (OS) and used them to study the full life cycle of plants. The Bulgarian–Russian-developed Svet Space Greenhouse (SG) system was upgraded on the Mir OS in 1996. The US developed Gas Exchange Measurement System (GEMS) greatly extends the range of environmental parameters monitored. The Svet-GEMS complex was used to grow a fully developed wheat crop during 1996. The growth rate and development of these plants compared well with earth grown plants indicating that the root zone water and oxygen stresses that have limited plant development in previous long-duration experiments have been overcome. However, management of the root environment during this experiment involved several significant changes in control settings as the relationship between the water delivery system, water status sensors, and the substrate changed during the growth cycles.

ELECTROCHEMICAL PH CONTROL IN HYDROPONIC SYSTEMS

This paper reports an innovative method based on electrochemistry to adjust the pH in nutrient solutions used in hydroponics. The required quantity of H or OH ions is produced insitu through electrolytic water decomposition. Because the direction and rate of electrochemical reactions can be easily manipulated by controlling the polarity and voltage applied between electrodes, the most important advantage of this method in comparison to traditional pH control using chemicals is the possibility to accomplish accurate and reliable pH control to within a narrow, preset pH range. Moreover, additional positive effects of improving the quality of added raw water such as alkalinity control, reducing the concentration of sodium, and water disinfection can be accomplished in the same electrolytic unit. Electrochemical technology offers possibilities to eliminate the risk of pH control failures due to overdoses and excludes the necessity of having reagent (acid and base) storage tanks and of handling these hazardous materials. Important savings of reagents, dosage and mixing equipment, storage tanks and improved environment and safety objectives can be realized. Available greenhouse space can be used more efficiently.

Project of conveyer-type space greenhouse for cosmonauts' supply with vitamin greenery

Design and advantages of conveyer-type growth chamber PHYTOCYCLE with a cylindrical crop surface are featured. Based on the results of testing, an experimental prototype of conveyer-type vegetable greenhouse VITACYCLE for space vehicles is being developed at the SSC-IBMP in conjunction with a number of institutions of the Russian space industry to provide space crews with fresh greenery. Rated daily production of the greenhouse is 150 g of eatable biomass with power consumption of 1 kW. The system is to be mounted within the life support module of international space station Alpha (ISSA). Design of the greenhouse is outlined. Brief description, state-of-the-art, and further plans regarding VITACYCLE elaboration and construction are presented.

Six-month space greenhouse experiments — A step to creation of future biological life support systems

SVET Space Greenhouse (SG) — the first automated facility for growing of higher plants in microgravity was designed in the eighty years to be used for the future BLSS. The first successful experiment with vegetables was carried out in 1990 on the MIR Space Station (SS). The experiments in SVET SG were resumed in 1995, when an American Gas Exchange Measurement System (GEMS) was added. A three-month wheat experiment was carried out as part of MIR-SHUTTLE'95 program. SVET-2 SG Bulgarian equipment of a new generation with optimised characteristics was developed (financed by NASA). The new SVET-GEMS equipment was launched on board the MIR SS and a successful six-month experiments for growing up of two crops of wheat were conducted in 1996–1997 as part of MIR-NASA-3 program. The first of these “Greenhouse” experiments (123 days) with the goal to grow wheat through a complete life cycle is described. Nearly 300 heads developed but no seeds were produced. A second crop of wheat was planted and after 42 days the plants were frozen for biochemical investigations. The main environmental parameters during the six-month experiments in SVET (substrate moisture and lighting period) are given. The results and the contribution to BLSS are discussed.

An Improved Method for Seed-Bank Analysis: Seedling Emergence After Removing the Soil by Sieving

1. The seedling emergence method for assessing the size of the seed bank is improved by washing soil samples on a fine sieve and spreading the thus concentrated samples in a 3-5 mm thick layer on sterilized potting compost. 2. The method largely increases the number of seedlings that emerge as compared to unconcentrated samples. Hand-sorting afterwards shows that the germination rates vary between 81 and 100% of the viable seeds present. 3. Ninety-five per cent of the seedlings will emerge within 6 weeks using this method. 4. The method greatly reduces the greenhouse space needed and enables examination of large sample volumes.