Tag Archives: LED

173–186 I. Alsina, L. Dubova and M. Duma
Assessment of common bean responses to light spectral composition and microbial inoculation using non-destructive methods
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Assessment of common bean responses to light spectral composition and microbial inoculation using non-destructive methods

I. Alsina¹*, L. Dubova¹ and M. Duma²

¹Latvia University of Life Sciences and Technologies, Faculty of Agriculture and Food Technology, Institute of Soil and Plant Sciences, 2 Liela street, LV3001 Jelgava, Latvia
²Latvia University of Life Sciences and Technologies, Faculty of Agriculture and Food Technology, Food Institute, 2 Liela street, LV3001 Jelgava, Latvia
*Correspondence: Ina.Alsina@lbtu.lv

Abstract:

. Non-destructive methods are increasingly used to evaluate plant physiological status. This study assessed the applicability of spectrometry and chlorophyll fluorescence for monitoring common bean (Phaseolus vulgaris) responses to light quality and microbial seed inoculation. A two-factor growth chamber experiment was conducted using LED lighting of equal intensity but different red-to-blue ratios (1:1, red-dominated, blue-dominated) and seeds that were either uninoculated or inoculated with Rhizobium phaseoli strains or Proseed-Met. Non-destructive measurements were performed on the same leaves using a spectroradiometer RS-3500 and a FluorPen FP110 fluorometer. Vegetation indices were calculated to evaluate stress, pigment content, senescence, and water status, while fluorescence parameters described photosynthetic performance. Spectrometric indices more clearly reflected light treatment effects, showing higher pigment content under red light, greater senescence under balanced light, and increased stress under red-dominated spectra. Fluorescence parameters were mainly affected by microbial inoculation and were higher in inoculated plants. Limited correlations between the two methods indicated that they capture different aspects of plant physiology. Blue-dominated light increased pod number, whereas red light reduced pod and seed mass. Microbial inoculation alone did not significantly affect yield, but the highest seed yield was observed in Rhizobium-inoculated plants under blue light. The results highlight the importance of light spectral composition for bean productivity and support the combined use of spectrometric and fluorescence methods for comprehensive physiological assessment.

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1926-1932 I. Alsiņa, L. Dubova, M. Dūma, I. Erdberga, I. Augšpole, D. Sergejeva and A. Avotiņš
Lighting source as cause of changes in cucumbers’ physiology and morphology
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Lighting source as cause of changes in cucumbers’ physiology and morphology

I. Alsiņa¹*, L. Dubova¹, M. Dūma², I. Erdberga¹, I. Augšpole¹, D. Sergejeva¹ and A. Avotiņš³

¹Latvia University of Life Sciences and Technologies, Faculty of Agriculture, Institute of Plant and Soil Science, Liela street 2, LV-3001 Jelgava, Latvia
²Latvia University of Life Sciences and Technologies, Faculty of Food Technology, Department of Chemistry, Liela street 2, LV-3001 Jelgava, Latvia
³Riga Technical University, Faculty of Power and Electrical Engineering, Kaļķu street 1, LV-1658 Riga, Latvia
*Correspondence: Ina.Alsina@llu.lv

Abstract:

The demand of fresh fruits and vegetables is growing. Therefore cultivation of them is essential all year round. The growth in the dark period of a year is not imaginable without artificial lighting sources. Therefore the experiments were carried out to investigate the effects of three different lighting sources on the growth of cucumbers at the early stages of development. Plants were grown in the polycarbonate greenhouse under three different lighting sources: Led cob Helle top LED 280, induction lamp and high pressure sodium lamp Helle magna. Cucumbers were grown in 16h photoperiod with PAR at the tips of plants 200 ± 20 μmol m-2 s-1. Plant growth parameters, specific leaf area, pigments, phenols and flavonoids content in leaves, leaf light reflection parameters were determined. Results showed that cucumber plants grown under Led cob Helle top LED 280 in average were smaller, with less chlorophyll, carotenoids and phenols, but leaves have higher chlorophyll a and b ratio and specific leaf area in comparison with traditionally used in greenhouses High Pressure Sodium Lamps (HPSL). Cucumber plants grown under Induction lamp in average were shorter, but with larger leaf area, with higher chlorophyll and carotenoids content, but decreased phenols content in comparison with HPSL. Lichtenthaler index 1 (LIC1) and NDVI are useful for assessing the physiological state of cucumber plants. Despite the fact that the plants grow well and develop normally under all lamps, the results show that sodium lamps are the most suitable for cucumbers. Further research is needed to adjust LED lighting for cucumber cultivation.

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982–986 M-Q. Dang, J. Šafránková, M. Libra, V. Poulek, P. Kouřím and J. Sedláček
Autonomous photovoltaic system for night-time lighting in the stable
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Autonomous photovoltaic system for night-time lighting in the stable

M-Q. Dang, J. Šafránková, M. Libra, V. Poulek, P. Kouřím and J. Sedláček

Czech University of Life Sciences Prague, Kamycka 129, CZ16521 Prague, Czech Republic
*Correspondence: janicka.safrankova@gmail.com

Abstract:

Autonomous photovoltaic (PV) systems are suitable, for example, for powering various appliances or scientific instruments in the field, for automatic data collection, for signaling, etc. At the Czech University of Life Sciences Prague, we have designed an experimental autonomous PV system designed for night-time lighting for orientating in a stable for horses. The article describes the construction of a PV system with a PV panel rated at 170 Wp, with a lead-acid accumulator and a 1,5 W LED light source. The data collection was automated. The data evaluation shows that during the whole year, the PV system has been recharged and there was no lighting failure. The paper also presents important measured characteristics.

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