Greenhouse Facilities Research Articles

Relationship between the Dynamic Characteristics of Tomato Plant Height and Leaf Area Index with Yield, under Aerated Drip Irrigation and Nitrogen Application in Greenhouses

The current study was undertaken to investigate the dynamic characteristics of the tomato crop, such as its plant height and leaf area index (LAI), based on the effective cumulative temperature. This was assessed under aerated drip irrigation (ADI) conditions and the application of a specific nitrogen (N) dose, and their relationship with the yield of the crop was formulated. The study was conducted in a greenhouse located in Zhengzhou, Henan province, China. The assessment conditions were the two irrigation methods, ADI and conventional drip irrigation (CK), and the three N application rates, i.e., 0, 140, and 210 kg ha−1. The logistic and Richards models were used to fit dynamic equations for plant height and LAI under the different treatments to quantify the characteristic parameters and understand their relationship with yield. The results revealed that the growth of the tomato plant fitted well with the logistic and Richards model at R2 > 0.98 (p < 0.01), regardless of the treatments. ADI and N application were found to significantly increase the maximum growth rate and average growth rate over the rapid growth period based on the tomato plant height and LAI. They were also noted to reduce the effective cumulative temperature at which plant height entered the rapid growth period (p < 0.05), thereby increasing the time spent in the nutritional growth phase. This is an essential precursor for the better development of subsequent reproductive organs. Tomato yields also confirm it: the highest yield of 85.87 t ha−1 was obtained with 210 kg N ha−1 for the ADI treatment, with an increase of 13.8%, 12.2%, and 39.6% compared to the CK–210 kg N ha−1, ADI–140 kg N ha−1, and ADI–0 kg N ha−1 treatments, respectively (p < 0.05). Grey correlation analysis showed that the characteristic parameters closely related to yield were all from the ADI and N application treatments. Furthermore, it was observed that the effective cumulative temperature and the maximum growth rate of the LAI at which the LAI entered the slow growth phase were the key growth characteristic parameters affecting tomato yield. This study provides a scientific basis for regulating the growth dynamics and yield of vegetables in greenhouse facilities under ADI and N application.

Prevalence of primary non-communicable morbidity in vegetables greenhouse workers

Introduction. In previous studies, we have shown that, despite the modernization of technological processes, working conditions in greenhouse vegetable growing continue to be harmful to the 3rd degree (class 3.3) with a proven occupational risk of development of production-related diseases of the circulatory system, musculoskeletal system, and respiratory system. In this regard, it seemed relevant to clarify the closeness of the relationship between work experience in the occupation and age status with the prevalence of primary non-communicable morbidity (PNCM) in female vegetable growers dealing with protected soil and its nosological structure. Materials and methods. In this paper, we used the results of extended medical examinations of female vegetable growers at the greenhouse facility of JSC “Sovkhoz-Vesna”, conducted in the period from 2013 to 2017. The level and nosological structure of the primary morbidity in workers were analyzed in accordance with the generally accepted methodology. Results. It was found that two hundred forty eight general somatic diseases were diagnosed in female workers during the period from 2013 to 2017. The level of PNCM for different years of observation was in the range of 181.8 - 231.9% with a tendency to decrease. The first ranks in the structure of the PNCM were arterial hypertension (AH) - 19.4%, dorsalgia - 12.5%, benign mammary dysplasia (BMD) - 8.9%, chronic bronchitis (CB) - 7.7% and obesity - 7.3%. Correlations of the age factor with hypertension, BMD and obesity corresponded to the gradation of moderate positive associations, with dorsalgia were weak positive ones, with BMD of noticeable positive ones. The age factor made the greatest contribution to the formation of PNCM in relation to BMD (25.7%), CB (22.7%) and obesity (15.4%). In the case of occupational experience, weak negative associations occurred with the prevalence of hypertension and BMD, weak positive ones with CB; negligible ones with obesity and only with dorsalgia, moderate positive ones. The probation factor determined only the development of dorsalgia (12.3%); the contribution to the development of other PNCM ranged from 0.2 to 4.4%. The nature of seniority-age associations with nosologies of PNCM coincided with the trends in the distribution of vegetable workers with PNCM in the functions of age categories and occupational experience. Limitations. The limitation of the study was the use of data obtained during the examination of vegetable workers of only one greenhouse complex in the analysis of the influence of long-term factors on the prevalence of non-communicable diseases. Conclusion. Thus, the preservation of the service longevity of working women requires the introduction of complementary health-saving technologies based on the reduction of common risk factors for both occupationally determined pathology and socially significant non-communicable diseases, taking into account gender and age characteristics

The role of grafting in the productivity of tomato of extended cycle

Relevance. The purpose of the research: to study the effect of technological method (grafting) on tomatos productivity in the conditions of protected soil in the Tyumen region. Research objectives: based on the study of tomato rootstocks for the studied graft, to identify the most productive rootstock for subsequent use in LLC “Greenhouse facility “TyumenAgro” . Subject of research: protected ground conditions.The object of research: tomato hybrids F1 Maxeza, F1 Trovanzo and F1 Complis (as grafts), F1 Maxifort and F1 Emperador (as a rootstocks). The article also provides information on the use of the technological method of grafting when growing tomatoes in protected soil conditions in LLC “Greenhouse facility “TyumenAgro””.Methods. The productivity of tomatoes is taken into account from1 m2 in three-fold repetition. Crop accounting is carried out separately for each option as the fruit ripens, after 5–7 days. The results of crop accounting are processed by the method of variance analysis presented by B.A. Dospekhov. Results. In the course of research, it was found that the cultivation of tomato hybrids in conditions of lowvolume hydroponics, subject to phytosanitary measures, allows to increase the yield and quality of fruits. The highest yield for the crop cycle of 2018–2021 was observed in plants with Maxesa F1 graft and Emperador F1 rootstock, it amounted to 226.47 kg/m2. Based on the research, elements of a new technology will be proposed, characterized by significantly higher quality indicators of tomato productivity formation.

Methods of selection of soybean genotypes for tolerance to rain on pre-harvest

Soybean production chain is facing serious challenges for high quality seed and grain production. This paper proposes a simple method to select genotypes with tolerance to excess moisture. The study was divided into three stages. Stage I consisted in plant production and standardization of maturity for 25 seeding genotypes in Passo Fundo-RS during 2013-2014 growing season 500 plants were harvested from each genotype at R7-R8 stage. Stage II was composed by rainfall and temperature simulation assays which were carried out in greenhouse facility of Cambé-PR. Stage III consisted of physiological seed quality determination. Samples were evaluated for 1000-seeds weight, germination, first count of germination, accelerated aging and shoot and root dry matter. Simulation of rain for three days during preharvest period resulted in reduced seed viability and vigor in genotypes DMARIO59i, A4725RG, NS4823 and FPS URANO RR indicating consideration of the harvesting time close to R8 stage for high quality seed production in these genotypes.

Intellectual Scenario-synergetic Control of the Humidity and Temperature Regime of the Greenhouse Facilities

The article substantiates the management of the humidity and temperature regime of greenhouse complexes on the basis of a scenario-synergetic approach. The scenarios for controlling the temperature and humidity conditions in the greenhouse using the approach of fuzzy neural networks are formed. The structure of an automated control system for technological processes is developed, which provides automated collection and processing of information for the implementation of control actions in order to improve the efficiency of the greenhouse complex on the basis of a scenario-synergetic approach. The corresponding fuzzy neural networks are synthesized for a synergistic assessment of the interaction of technological parameters. Estimation of the root-mean-square error in the synthesis of fuzzy neural networks confirms the possibility of their use for the synergistic formation of scenarios for controlling the temperature and humidity regime in greenhouses to reveal the presence of a synergistic effect. Production rules for scenario management of temperature and humidity conditions are formed. It is shown that the use of fuzzy neural networks for the formation of scenarios for controlling the humidity and temperature regime provides the possibility of obtaining the appropriate scenarios for making managerial decisions and their prompt correction.

Comprehensive Economic Benefits Evaluation Model of Greenhouse Photovoltaic

Abstract: Photovoltaic integrated greenhouse has become an important form of deep coupling between new energy power generation and facility agriculture. Greenhouse photovoltaic power generation will affect the light environment, thermal environment, and water environment of facility agriculture. The precise coupling modeling method of greenhouse photovoltaics and loads is to carry out the basis for the calculation of comprehensive economic benefits of greenhouse photovoltaics. This paper studies the deep coupling modeling method of greenhouse photovoltaic and greenhouse load, and accurately calculates the changes in the light environment, thermal environment, and water environment regulation load of facility agriculture caused by the laying of greenhouse photovoltaics. Firstly, the greenhouse photovoltaic power generation model and the environmental regulation load model of facility agriculture are established; secondly, the coupling relationship between greenhouse photovoltaic power generation and facility agricultural load is described, and on this basis, the comprehensive economic benefits evaluation model of photovoltaic power generation is proposed. The 10kV medium-voltage distribution network and facility agricultural greenhouse that exist in the northern region are used as the research objects. It verifies the validity of the photovoltaic comprehensive economic benefits evaluation model proposed in this paper.

Rooting green cuttings of Altai seabuckthorn cultivars in industrial-scale experiment

Green cutting propagation technologies of seabuckthorn ( Hippophae rhamnoides L.) are well developed and highly effective under optimal parameters of implementation. Differences in root development in most cases are connected with varietal specificity. In conditions of uncovered greenhouses, weather particularities can influence significantly on development of cuttings. Hence, the aim of investigation was to study the cultivar difference in root development of seabuckthorn green cuttings in a long-term industrial-scale experiment in conditions of uncovered greenhouse facilities. The experiments were carried out in forest-steppe area of Altai krai in 2018-2021. Seventeen seabuckthorn cultivars developed by Federal Altai Scientific Center of Agrobiotechnologies were taken as research objects. Significant varietal specificity of rooting ability of green cuttings has been established. The experiments showed that season particularities just slightly affect this parameter, indicating significant homeostasis of seabuckthorn cultivars in this regard. Altaiskaya, Ognivo, Gnom, Ethna, Elizaveta and Athena varieties showed the highest level of rhizogenesis with everage rooting percentage from 91.2 to 95.5 %. Group of low rooted cultivars included Azhurnaya, Aurelia, Zlata, Sudarushka and Avgustina with rooting percentage from 70.5 to 79.7 %. Other cultivars showed intermediate figures. High correlation level (0.590.21) was shown between total root quality and rhizogenesis ability. Cultivars which demonstrated high rooting percentage also formed high level of first grade seedlings. In this regard, the best cultivars were Altaiskaya, Gnom and Ognivo, which formed 79.1, 82.1 and 83.8 % of first-grade seedlings, respectively. Low rooting ability was observed in cultivars Avgustina, Sudarushka and Zlata, which provided only 55.464.4 % of first-grade planting material. The variation coefficient of seabuckthorn standard seedlings was low and did not exceed 9.7 % for Avgustina cultivar. The variation of seedlings quality was at a higher level - u p to 27.3 % for cv. Sudarushka, however, for the rest of the cultivars it was low or medium and ranged from 2.7 to 18.7 %. According to the results of cluster analysis, the seabuckthorn cultivars were divided into three separate groups - slow-, medium- and fast-to-root genotypes.

Game theory and its application in food security: research of the greenhouse facilities of the republic of Uzbekistan

Game theory has recently increased significantly in its role in various fields of science and areas of the country's life. It is applicable today in the economy of any country for the adoption of general economic tasks, the study of strategic problems, systems for stimulating the development of industries, the development of organizational structures. The application of game theory is considered an important aspect in the implementation of the tasks set at the state level. The Republic of Uzbekistan is considered one of the countries that have recently been trying to reach a significant stage of development, which has a fruitful effect on agriculture and greenhouse economy, their general improvement. The purpose of this article is to analyze the possibilities of using game theory in the field of greenhouse facilities in the Republic of Uzbekistan. This goal will be achieved through the analysis of the main modern scientific works, the study of analytical data and statistical indicators of the industry. The greenhouse economy of the Republic of Uzbekistan today is at a stage when significant changes are needed, the use of the most modern technologies both in the field of economic services for the industry, and fruitful interaction of individual parties. One of the most priority technologies for the development of individual areas of the greenhouse industry today is the so-called "game theory". Game theory is a prerequisite for the formation of separate and relevant directions for the development of the country's greenhouse economy, it establishes the rules for implementing the interaction of the parties-players in the process of creating strategies, functions of specific structures.

Automated Detection of Greenhouse Structures Using Cascade Mask R-CNN

Automated detection of the content of images remains a challenging problem in artificial intelligence. Hence, continuous manual monitoring of restricted development zones is critical to maintaining territorial integrity and national security. In this regard, local governments of the Republic of Korea conduct four periodic inspections per year to preserve national territories from illegal encroachments and unauthorized developments in restricted zones. The considerable expense makes responding to illegal developments difficult for local governments. To address this challenge, we propose a deep-learning-based Cascade Mask region-based convolutional neural network (R-CNN) algorithm designed to perform automated detection of greenhouses in aerial photographs for efficient and continuous monitoring of restricted development zones in the Republic of Korea. Our proposed model is regional-based because it was optimized for the Republic of Korea via transfer learning and hyperparameter tuning, which improved the efficiency of the automated detection of greenhouse facilities. The experimental results demonstrated that the mAP value of the proposed Cascade Mask R-CNN model was 83.6, which was 12.83 higher than baseline mask R-CNN, and 0.9 higher than Mask R-CNN with hyperparameter tuning and transfer learning considered. Similarly, the F1-score of the proposed Cascade Mask R-CNN model was 62.07, which outperformed those of the baseline mask R-CNN and the Mask R-CNN with hyperparameter tuning and transfer learning considered (i.e., the F1-score 52.33 and 59.13, respectively). The proposed improved Cascade Mask R-CNN model is expected to facilitate efficient and continuous monitoring of restricted development zones through routine screening procedures. Moreover, this work provides a baseline for developing an integrated management system for national-scale land-use planning and development infrastructure by synergizing geographical information systems, remote sensing, and deep learning models.

Research Progress on Water–Fertilizer Coupling and Crop Quality Improvement and Its Implication for the Karst Rock Desertification Control

An important problem currently faced by karst rocky desertification management is the degradation of vegetation fruits, which encourages the search for a solution for the sustainable growth of vegetation. Water and fertilizer are key factors affecting crop quality (the formation of soluble solids, protein, amino acids, soluble sugar content, etc.). A comprehensive review of research related to water–fertilizer coupling and crop quality improvement may be beneficial for rocky desertification control. This study analyzed 427 related papers, and the results showed that: (1) the number of published papers showed an “S” curve growth trend over time, indicating that research in the field of water–fertilizer coupling has entered a mature stage after rapid growth, yet it is still in the initial stage in karst areas; (2) the research was mainly theoretical, but also included technology research and development, model construction, demonstration and extension, and monitoring and evaluation; (3) except for research related to greenhouse facilities, the research areas are mainly located in arid and semi-arid regions. The study further revealed (4) the frontier theory of water–fertilizer coupling and crop quality research. Finally, it was found that the theoretical and technical studies related to water–fertilizer coupling and crop quality improvement in karst areas are insufficient. Whether the existing theories and techniques are applicable to karst areas needs further verification. In addition to the areas of selecting germplasm with high water/fertilizer utilization efficiency and tolerance to rocky desertification, further improvement in the dynamic model of water–fertilizer coupling and the construction of a more applicable water–fertilizer coupling model could also be future research hotspots.

Accumulation of anthocyanins and phenolic acids and antioxidant activity of lettuce cultivars grown hydroponically and in the open ground

We assess the level of anthocyanins and phenolic acids accumulated in the leaves of lettuce cultivars grown hydroponically and in the open ground. In addition, the antioxidant activity of the cultivars under study was determined. The plant material was macerated overnight using a selected extractant. The anthocyanin concentration was determined by spectrophotometry, while the composition of anthocyanins and phenolic compounds was determined by reverse-phase high performance liquid chromatography. In general, anthocyanins in the extracts of all red-leaved lettuce cultivars were represented by cyanidin-3-(6″- malonylglucoside) with a small amount of its isomer – cyanidin-3-(3″-malonylglucoside). The highest level of anthocyanins was detected in the leaves of c.v. Thurinus, amounting up to 0.200 g per 100 g of fresh product for the intensively painted leaf areas. The cultivation of lettuce under the green-house conditions (hydroponically) leads to a significant reduction in the anthocyanin concentration in its leaves. The loss of anthocyanins during leaf drying was established to exceed 50%. Along with anthocyanins, the derivatives of caffeic acid, including chlorogenic (5-caffeoylquinic) acid, 5CQA, chicoric (3,4-caffeoyltartaric) acid, and 3,5- dicaffeoylquinic acid are important water-soluble compounds with antioxidant effects. The 5CQA accumulation was the highest, comprising 140 mg per 100 g of fresh weight (Red Thurinus). Antioxidant properties correlating with the level of anthocyanin accumulation were determined using the Folin-Ciocalteu method. In comparison with green-leaved cultivars, red-leaved lettuce was found to exhibit a greater antioxidant activity, thus representing a more valuable and functional food product. According to the obtained results, a system of additional illumination is required for intensification of the anthocyan biosynthesis aimed at obtaining highquality products cultivated hydroponically in green-house facilities.

A Study on the Construction Method of Airflow Fan and Fog Combined System for the Cooling of the Greenhouse Facility

A Study on the Construction Method of Airflow Fan and Fog Combined System for the Cooling of the Greenhouse Facility

Penanaman Hidroponik dan Olahannya Sebagai Pencegahan Berat Badan Kurang di Desa Cibitung Wetan, Pamijahan, Bogor

Trilogi University with the community ‘Kampung Ramah Lingkungan’ (KRL) Seroja Kahuripan have conducted underweight prevention services in Cibitung Wetan Village, Pamijahan, Bogor. This service activity aims to educate importance of nutritious food, train in creating greenhouses and hydroponic installations, cultivate vegetable crops and their processing to increase the food value as prevention of underweight. The method was carried out in several stages: 1) The preparation and coordination; 2) Implementation; and 3) monitoring and evaluation. Based on the data, it was known that 13,69% of children aged 0–23 months are observed with underweight with body weight far below the standard and 34,44% of children are approaching as underweight. Efforts to prevent underweight were carried out by strengthening the identity of partners, the construction of greenhouse and hydroponic installation as well as training in vegetable cultivation carried out by the team so that partners can be independent in providing nutritious food. The yields of vegetables and their processed products in form of nuggets and jerky have provided food value added increasement to partners. As a result, increasement in the number of partner members from 15 to 54 people, the formation of a group logo as identity reinforcement, the construction of greenhouse facilities and hydroponic installations series, increasement of partner’s knowledges and skills in hydroponic cultivation and crops processing, and increasement partner’s awareness of underweight issue. The results of partner’s satisfaction questionnaire showed that 85% were very satisfied with the program and they hoped for sustainable and further fostering.

Legalization of Cannabis and Agricultural Frontier Expansion.

The environmental impacts of cannabis cultivation have been an issue of growing concern, with legalization often framed as a means to introduce regulations that hinder damaging practices. However, the concept of frontier expansion presents the possibility that the widespread establishment of this new industry may institute an additional source of habitat encroachment. Here, through geospatial analysis, we employ Colorado as a case study to investigate the distribution of licensed recreational cannabis cultivators, potential habitat infringement of threatened and endangered species, and LULC change. From 2011 to 2016, licensed cannabis cultivation has resulted in over 67 ha of LULC change toward more developed land uses. In addition, nearly 15 km of new fencing was constructed establishing over 38 ha of fenced areas, and nearly 60 ha of vegetation was cleared. Much of this cannabis-driven LULC change is identified within the habitats of threatened and endangered species, as well as areas recognized as containing high biodiversity values with the potential for conservation. Thus, notable cannabis-driven frontier expansion is evident. Cannabis-driven LULC change is found to be primarily produced by outdoor and greenhouse facilities, as well as operations utilizing mixed-cultivation methods in rural areas. Therefore, policy instruments that inter alia encourage indoor cannabis cultivation in urban areas are recommended and discussed.

Irrigation decision model for tomato seedlings based on optimal photosynthetic rate

Soil moisture is a major environmental factor that influences tomato growth and development. Suitable soil moisture not only increases tomato production but also saves irrigation water. This paper developed an irrigation decision model, called soil moisture regulation model, for optimizing growth of tomato seedlings while saving water. The data used to establish models were collected from a multi-gradient nested experiment, in which temperature, photosynthetic photon flux density (PPFD), carbon dioxide (CO2) concentration and soil moisture were variables and the corresponding photosynthetic rate was measured. Subsequently, a prediction model of tomato photosynthetic rate was constructed using support vector regression (SVR) algorithm. With photosynthetic rate prediction model as fitness function, genetic algorithm (GA) was used to find the optimal soil moisture under each combination of the above environmental factors. Finally, back propagation neural network (BPNN) algorithm was used to establish a decision model of tomato irrigation, which could provide the optimal soil moisture under current environment. For the soil moisture regulation model constructed here, the coefficient of determination was 0.9738, the mean square error of the test set was 1.51×10-5, the slope of the verified straight line was 0.9752, and the intercept was 0.00916. This model demonstrated high precision, which thereby provides a theoretical basis for accurate irrigation control in the greenhouse facility environment. Keywords: irrigation, decision model, soil moisture, tomato, photosynthetic rate, machine learning DOI: 10.25165/j.ijabe.20211405.6148 Citation: Wan X B, Li B, Chen D Y, Long X Y, Deng Y F, Wu H R, et al. Irrigation decision model for tomato seedlings based on optimal photosynthetic rate. Int J Agric & Biol Eng, 2021; 14(5): 115–122.

Energy Minimisation in a Protected Cropping Facility Using Multi-Temperature Acquisition Points and Control of Ventilation Settings

Energy management in protected cropping is critical due to the high cost of energy use in high-tech greenhouse facilities. The main purpose of this research was to investigate the optimal strategy to reduce cooling energy consumption, by regulating the settings (opening/closing) of either vents or curtains during the day, at the protected cropping facility at Western Sydney University. We measured daily changes in air temperature and energy consumption under four treatments (open/closed combinations of vents and shade screens) and developed an optimal cooling strategy for energy management using multi-temperature acquisition points at different heights within a greenhouse compartment. The optimal treatment (vents open/curtains closed) reduced energy load at the rooftop, thereby maintaining a desirable plant canopy temperature profile, and reducing cooling energy. Daily energy consumption was lowest for vents open/curtains closed (70.5 kWh) and highest for vents closed/curtains open (121 kWh). It was also found that delaying the operation of opening and closing of vents and curtains until the plant canopy temperature reached 25 °C reduced cooling energy consumption and decreased heating energy consumption in the morning (e.g., 08:00 to 10:00). The estimated savings of 1.83 kWh per 1 °C cooling between the optimal (vents open/curtains closed) and least optimal (vents closed/curtains open) conditions had the potential for significant energy savings at 494 kWh per °C over a crop cycle of nine months in warm weather conditions. However, selection of the optimal cooling strategy utilising control of vents and curtains must also account for the impact from other greenhouse environmental factors, including light, humidity, and CO2 concentration, which may be crop specific.

In Case You Haven't Heard…

Warwick, New York, will have a cannabis cultivation site soon, with construction already underway by Green Thumb Industries of Chicago. The location is on the site of a former prison, where there is already a greenhouse and processing facility. The company has invested $150 million to remodel the site, which will create 100 construction jobs and 100 permanent positions with benefits, according to an article in the Sept. 9 Times‐Union. Green Thumb purchased the 40 acres of former prison grounds for $3.3 million in May, after Orange County approved a 15‐year tax abatement. The $3.3 million covered the town's remaining debt on the cost of the purchase of the prison property from the state. The town is not ready, however, to allow on‐site cannabis consumption at its cafes or to allow marijuana dispensaries at all.

Development of a robust nitrate sensor for online measurements

According to the EU Water Framework Directive the emission of nutrients and plant protection products to water bodies should be reduced dramatically. In practice threshold values for water bodies are exceeded due to leakages, discharges and unexpected problems from greenhouse facilities. Nitrate eutrophicates surface water. In the Netherlands nutrient solution recirculation in soilless cultivation is obliged and discharge is regulated to yearly crop specific nitrogen concentrations. However, water authorities still measure exceedances in surface water, leading to an interest real-time measurement of nitrogen or nitrate to have data faster available. Adjustments in nutrient recipes in greenhouses are based on a 7-14 days analysis of drainwater by sending it to a laboratory. This practice is suboptimal since the loss in nutrients is higher than necessary and it might even reduce crop development. Besides it is time consuming and often expensive. In areas where the results of the laboratory are not fast available, a nitrate sensor may even play an important role in creating the right solution for the plants. With a real-time measuring nitrate sensor, it is possible to fertigate more accurately which increases the harvest/quality of the crop with a lower environmental footprint. Besides, such a nitrate sensor has also a large scientific value since the dynamic nitrate uptake by the crop can be studied at a scale of minutes instead of days. A start has been made to analyse available methods for measuring nitrate, and in this study we will present an innovative optical fibre based nitrate sensor using an algorithm which has been tested in a greenhouse setting at field conditions. This UV-VIS spectroscopy system in combination with the developed model can be used for online monitoring of nitrate concentrations in hydroponic solutions, without the use of any reagents or need for recalibration, to enhance the efficiency and safety of greenhouse systems with respect to water reuse and recycling.

The Breeding of Winter-Hardy Malting Barley

In breeding winter malting barley, one recurring strategy is to cross a current preferred spring malting barley to a winter barley. This is because spring malting barleys have the greatest amalgamation of trait qualities desirable for malting and brewing. Spring barley breeding programs can also cycle their material through numerous generations each year—some managing even six—which greatly accelerates combining desirable alleles to generate new lines. In a winter barley breeding program, a single generation per year is the limit when the field environment is used and about two generations per year if vernalization and greenhouse facilities are used. However, crossing the current favored spring malting barley to a winter barley may have its downsides, as winter-hardiness too may be an amalgamation of desirable alleles assembled together that confers the capacity for prolonged cold temperature conditions. In this review I touch on some general criteria that give a variety the distinction of being a malting barley and some of the general trends made in the breeding of spring malting barleys. But the main objective of this review is to pull together different aspects of what we know about winter-hardiness from the seemingly most essential aspect, which is survival in the field, to molecular genetics and gene regulation, and then finish with ideas that might help further our insight for predictability purposes.

The Utilization of User Fees to Subsidize Greenhouse and Growth Chamber Facilities at Public and Land Grant Universities

Greenhouse and growth chamber operating and maintenance costs continue to escalate while budgets remain stagnant. As a result, many universities struggle to find the necessary funds for the maintenance, repair, and replacement of basic research infrastructure needs. A survey was conducted to develop an understanding of how user fee systems contribute to funding stability, and how they are designed and managed in support of greenhouse and growth chamber facilities at colleges of agriculture throughout the United States. Where user fees have been implemented, the majority of greenhouse and growth chamber facilities are managed centrally, and are administered by agricultural experiment station (AES) directors or facility managers. Regardless of the administrative authority, most systems use an advisory committee to set fee schedules and determine policies. The majority of user fees are allocated back to the specific facility, with the majority of funds in general used to help pay for indirect expenses. The findings also indicate that user fees make more efficient use of space by providing faculty with a financial incentive to minimize their project area and to conduct experiments quickly.