Anna Kołton

Bio: Anna Kołton is an academic researcher from University of Agriculture, Faisalabad. The author has contributed to research in topics: Ascorbic acid & Pepper. The author has an hindex of 10, co-authored 41 publications receiving 368 citations. Previous affiliations of Anna Kołton include University of Agriculture in Krakow & University of Stavanger.

Light use efficiency for vegetables production in protected and indoor environments

Abstract: In recent years, there is a growing interest for vegetables production in indoor or disadvantaged climatic zones by using greenhouses. The main problem of crop growing indoor or in environment with limited light availability is the correct choice of light source and the quality of lighting spectrum. In greenhouse and indoor cultivations, plant density is higher than in the open field and plants have to compete for light and nutrients. Nowadays, advanced systems for indoor horticulture use light emitting diodes (LED) for improving crop growth, enhancing the plant productivity and favouring the best nutritional quality formation. In closed environments, as indoor growing modules, the lighting system represents the only source of light and its features are fundamental for obtaining the best lighting performances for plant and the most efficient solution. LED lighting engines are more efficient compared to the lighting sources used traditionally in horticulture and allow light spectrum and intensity modulations to enhance the light use efficiency for plants. The lighting distribution and the digital controls are fundamental for tailoring the spectral distribution on each plant in specific moments of its growth and play an important role for optimizing growth and produce high-quality vegetables. LED lights can increase plant growth and yield, but also nutraceutical quality, since some light intensities increase pigments biosynthesis and enhance the antioxidants content of leaves or fruits: in this regards the selection of LED primary light sources in relation to the peaks of the absorbance curve of the plants is important.

The Complex Issue of Urban Trees—Stress Factor Accumulation and Ecological Service Possibilities

Abstract: This review paper is the first that summarizes many aspects of the ecological role of trees in urban landscapes while considering their growth conditions. Research Highlights are: (i) Plant growth conditions in cities are worsening due to high urbanization rates and new stress factors; (ii) Urban trees are capable of alleviating the stress factors they are exposed to; (iii) The size and vitality of trees is related to the ecological services they can provide. Our review shows, in a clear way, that the phenomenon of human-related environmental degradation, which generates urban tree stress, can be effectively alleviated by the presence of trees. The first section reviews concerns related to urban environment degradation and its influence on trees. Intense urbanization affects the environment of plants, raising the mortality rate of urban trees. The second part deals with the dieback of city trees, its causes and scale. The average life expectancy of urban trees is relatively low and depends on factors such as the specific location, proper care and community involvement, among others. The third part concerns the ecological and economic advantages of trees in the city structure. Trees affect citizen safety and health, but also improve the soil and air environment. Finally, we present the drawbacks of tree planting and discuss if they are caused by the tree itself or rather by improper tree management. We collect the latest reports on the complicated state of urban trees, presenting new insights on the complex issue of trees situated in cities, struggling with stress factors. These stressors have evolved over the decades and emphasize the importance of tree presence in the city structure.

Leaf Morphology, Photosynthetic Performance, Chlorophyll Fluorescence, Stomatal Development of Lettuce (Lactuca sativa L.) Exposed to Different Ratios of Red Light to Blue Light

Abstract: Red and blue light are both vital factors for plant growth and development. We examined how different ratios of red light to blue light (R/B) provided by light-emitting diodes affected photosynthetic performance by investigating parameters related to photosynthesis, including leaf morphology, photosynthetic rate, chlorophyll fluorescence, stomatal development, light response curve, and nitrogen content. In this study, lettuce plants (Lactuca sativa L.) were exposed to 200 μmol⋅m(-2)⋅s(-1) irradiance for a 16 h⋅d(-1) photoperiod under the following six treatments: monochromatic red light (R), monochromatic blue light (B) and the mixture of R and B with different R/B ratios of 12, 8, 4, and 1. Leaf photosynthetic capacity (A max) and photosynthetic rate (P n) increased with decreasing R/B ratio until 1, associated with increased stomatal conductance, along with significant increase in stomatal density and slight decrease in stomatal size. P n and A max under B treatment had 7.6 and 11.8% reduction in comparison with those under R/B = 1 treatment, respectively. The effective quantum yield of PSII and the efficiency of excitation captured by open PSII center were also significantly lower under B treatment than those under the other treatments. However, shoot dry weight increased with increasing R/B ratio with the greatest value under R/B = 12 treatment. The increase of shoot dry weight was mainly caused by increasing leaf area and leaf number, but no significant difference was observed between R and R/B = 12 treatments. Based on the above results, we conclude that quantitative B could promote photosynthetic performance or growth by stimulating morphological and physiological responses, yet there was no positive correlation between P n and shoot dry weight accumulation.

Renewable and sustainable energy saving strategies for greenhouse systems: A comprehensive review

Abstract: In this study, a comprehensive review focusing on key strategies of energy saving and climate control technologies for greenhouses is presented. Following the brief and concise assessment of existing greenhouse systems in terms of their role in total energy consumption; cost-effective, energy-efficient and environmentally friendly technologies are analyzed in detail for potential utilization in greenhouses for notable reductions in energy consumption and emission levels. The technologies considered within the scope of this research are mainly renewable and sustainable based solutions such as photovoltaic (PV) modules, solar thermal (T) collectors, hybrid PV/T collectors and systems, phase change material (PCM) and underground based heat storage techniques, energy-efficient heat pumps, alternative facade materials for better thermal insulation and power generation (heat insulation solar glass, PV glazing, aerogel and vacuum insulation panel, polycarbonate sandwich panels), innovative ventilation technologies using pre-heating and cooling (high performance windcatchers) and efficient lighting systems. The findings from the research clearly reveal that up to 80% energy saving can be achieved through appropriate retrofit of conventional greenhouses with a payback period of 4–8 years depending on climatic conditions and crop type.

Photovoltaic agriculture - New opportunity for photovoltaic applications in China

Abstract: Photovoltaic industry has been an important development direction of China's strategic emerging industries since 2012, and more and more attentions have been paid to broaden the domestic demand to solve the problem of overcapacity of China's PV industry. Photovoltaic agriculture, the combination of photovoltaic power generation and agricultural activities, is a natural response to supply the green and sustainable electricity for agriculture. There are several main application modes of photovoltaic agriculture such as photovoltaic agricultural greenhouse, photovoltaic breeding, photovoltaic wastewater purification, photovoltaic water pumping and new type rural solar power station. Photovoltaic agriculture can effectively alleviate the contradiction between more population and less land, powerfully promote the development of controlled environmental agriculture, evidently increase economic benefits of farmers, and significantly improve environment due to emissions reduction in China. In recent years, photovoltaic agriculture has a rapid development in China due to powerful support policies, flourishing controlled environmental agriculture, policy-oriented rural electrification and promising electric machinery for greenhouse. Therefore, photovoltaic agriculture provides new opportunity for China's photovoltaic industry, thus not only to solve the dilemma of overcapacity for China's photovoltaic industry effectively, but also to accelerate the development of modern agriculture in China. However, the more theoretical researches and practical exploration must be conducted to optimize the combination of photovoltaic power generation and agricultural planting. And the unified standards must be established to standardize the design and scale of projects of photovoltaic agriculture. Also, photovoltaic enterprises need to produce widely applicable photovoltaic products for agricultural production and farmers’ life.