In traditional climate diagrams a fixed coefficient (α) between temperature and precipitation has been adopted. It has been shown, however, that such an approach does not correctly describe the conditions of the climatic balance in Poland for the entire growing season. In this paper, a different solution to this problem is proposed - the introduction of a variable coefficient for individual months. The analysis of patterns of climatic variables over the year supports the hypothesis that in order to estimate ETo only by means of mean air temperature (ETo = α·T), the coefficient α should be variable for the individual months of the vegetative period. The values of the coefficient were empirically determined for use in calculating daily and monthly ETo. The newly proposed coefficients α were different from those determined with the standard climate diagram (published by Walter, Lieth 1967). The introduction of the variable value α into the computational model markedly improved the quality of the estimation of ETo. The mean bias errors determined for the estimation of ETo on the basis of temperature and the changing value of α were considerably lower than for the estimation of ETo with a fixed value of α. This provides the possibility of a more accurate presentation of periods of both excess and shortage of precipitation.
The suitability of capacitance probes for measuring the actual variations in substrate water content in container-grown ornamental species (Lawson cypress) was examined. The probes were installed in the plant containers. Weighing measurement data on water loss was used to assess the actual changes in substrate water content (plant water use). In an additional test, an evaluation of temperature sensitivity of the capacitance probe was performed under laboratory conditions. The probe was placed in a container containing the growing medium (peat substrate) with a defined (stable) moisture content. The substrate temperature was modified and the changes in probe output were recorded. The experiment demonstrated the existence of the effect of temperature on the quality of soil moisture measurements conducted with the capacitance method. The accuracy of the results obtained from measurements with dielectric sensors in relation to the data obtained by means of weighing platforms depended largely on the temperature profile of the measured medium. It was demonstrated that temperature variations explained 99% of the observed differences in the results of moisture content measured with the capacitance method. Due to the fact that there is no possibility of developing universal factors (for different sensors and substrates) for correcting the influence of temperature, this relationship should be defined independently for a given type of crop and the measuring system available.
The increasing role of perennials in ornamental nurseries requires the elaboration of efficient and accurate irrigation control of this specific group of plants. The experiment was conducted in 2015 in Research Institute of Horticulture, in Skierniewice. The aim of the study was to determine the water requirements and designate the specific evapotranspiration crop coefficient Kc of several perennials, commonly grown in Polish ornamental nurseries. Water requirements of perennials were evaluated using weighing lysimeters. At the same time the recorded climate parameters allowed to calculate the potential evapotranspiration (ET0). Lysimeter measurements and meteorological data allowed determine specific to each species crop coefficient (Kc). The Kc values were determined by dividing ETc by ET0. The obtained results showed that irrespectively of plant growth phase there is strong correlation between climate parameters and real crop evapotranspiration (ETc) of six evaluated perennials: Anemone hupehensis ‚Prinz Heinrich’, Echinacea purpurea ‘Guava Ice’, Hemerocallis, ‘Sandra Elisabeth’, Salvia nemorosa ‘Mainacht’ and Veronica spicata ‘Royal Candles Glory’. The Kc coefficients of all species were changed during the growth season and increased according to plant development and percentage of ground coverage of soil in the lysimeter by leaves. The strong, positive correlation was shown for daily and hourly calculated crop evapotranspiration and potential evapotranspiration (ET0) obtained from weather station. Determination of crop coefficients for ornamental perennials is essential for precise calculation of water doses and irrigation controlling in the nurseries.
Spring frosts can cause very significant losses on fruit farms. The most common method of active protection against frost is sprinkling. The aim of this study was to assess the effectiveness of a sprinkling system used to protect apple trees against the effects of a spring frost. The experiment was conducted on the Mączewscy Fruit Farm. The orchard in which the observations were made is equipped with a system of sprinklers. When the temperature readings showed values close to zero, the sprinkler system was activated. Due to a limited water supply, one row of sprinklers had not been activated, and thus some of the trees were not sprayed at all. The assessment of fruit yield carried out in the autumn of 2015 demonstrated high effectiveness of the sprinkling used to protect apple trees against the spring frost. The frost had damaged most of the flowers of the unprotected trees, which resulted in a decrease in yield of as much as 85-93%.
The usefulness of estimating hourly reference evapotranspiration for assessing the water requirements of plants over a 24-hour period was determined in the study. The values of hourly (ET0,h) and daily (ET0,d) evapotranspiration were calculated using the Penman-Monteith (PM) model. The daily ET0 was calculated automatically by the meteorological station, and the evapotranspiration values for individual hours were calculated using spreadsheet software. To verify the values of evapotranspiration calculated with these two approaches in relation to the actual water needs of grass, lysimetric measurements were performed. Additionally, substrate moisture content and temperature were measured using capacitance probes. The values of evapotranspiration estimated with the hourly PM model were higher than those determined with the daily model. An accuracy of the hourly model in relation to the data measured with a weighing lysimeter depended largely on the quality of the reproduction of meteorological parameters at the site of the crop. Observed underestimation of the actual daily evapotranspiration was presumably due to the use of air temperature values in the calculations (measured at a height of 2 m by the weather station). During strong solar radiation the air temperature was much lower than the temperature of the upper layer of the substrate in the weighing lysimeter. Reference evapotranspiration was recalculated by introducing into the hourly PM model the measured values of substrate temperature. After taking into consideration the higher temperatures, the calculated values of evapotranspiration increased, and the regression model took the form: y = 1.01x + 0.014 (R2 = 0.90), which proves the proportionality of the calculated and measured (actual water needs determined with the weighing lysimeter) data. Reliable data on the hourly variations in evapotranspiration over a 24-hour period can be a great tool for use in controlling the irrigation of plants grown in a limited volume of substrate.
Rośliny truskawki (odmiany „Elsanta” „Grandarosa”) uprawiane w szklarni w okresie zimowo-wiosennym (luty-maj) doświetlano przy pomocy lamp sodowych lub LED (diody emitujące światło czerwone, niebieskie oraz w zakresie bliskiej podczerwieni). Kombinację kontrolną stanowiły rośliny rosnące w warunkach naturalnego światła. Prowadzono pomiary intensywności wymiany gazowej oraz natężenia zielonej barwy liści (względna zawartość chlorofilu). Określono plonowanie roślin, a po zakończeniu doświadczenia wykonano analizę budowy morfologicznej roślin, mierząc masę i powierzchnię liści, masę korzeni oraz średnicę korony. Stwierdzono zróżnicowaną reakcję ocenianych odmian na doświetlanie. Zastosowane światło LED spowodowało zwiększenie natężenia fotosyntezy roślin odmiany „Grandarosa”. Rośliny te charakteryzowały się także intensywniejszym wzrostem i większym plonowaniem w porównaniu do roślin niedoświetlanych. W przypadku odmiany „Elsanta” przebieg procesów fizjologicznych, wzrost i plonowanie roślin nie były uzależnione od zastosowanego doświetlania.
EN
The objective of the study was to evaluate the physiological response and growth of strawberry plants grown under different light treat-ment. During cultivation period (February-May), the plants (two cultivars: ‘Elsanta’, ‘Grandarosa’) received supplemental artificial lighting provided by standard high-pressure sodium lamps or high-power solid-state lighting modules with red, blue and far red LEDs. Quantum irradiance in the both combinations was maintained at the same level. The third group of plants (control combination) was grown under the natural light (without sup-plemental lighting). The following measurements were taken: photosynthetic rate, leaf greenness index (relative chlorophyll content), fruit yield and the most important morphological parameters (fresh weight of plant organs, leaf surface area, crown diameter). The results showed that supplemental illumi-nation using LED light source affected photosynthesis (higher rates), growth (higher foliage weight and area) and productivity of ‘Grandarosa’ straw-berry plants. On the opposite, no significant effect of supplemental artificial lighting on performance of ‘Elsanta’ plants was recorded. The obtained results showed that LED lamps could be used in greenhouse lighting systems. However, much work still has to be done to optimize lighting spectrum of LED modules for the cultivation of the specific crop species and cultivars.
W doświadczeniu oceniano wpływ doświetlania lampami LED na rozwój mikrosadzonek truskawki podczas aklimatyzacji. Nieukorzenione mikrosadzonki odmiany „Pink Rosa” z laboratorium in vitro, oczyszczone z agaru. posadzono do multiplatów, do podłoża składającego się z wełny mineralnej chłonącej i niechłonacej (1:1). Rośliny uprawiano w kamerach wzrostowych zapewniając im wysoką wilgotność (80-90%), temperaturę 20-22°C oraz doświetlając je 16 godzin na dobę. Źródłem światła były: lampa sodowa 400 W (HPS), lampa LED – DAPLON-plus/2011 skonstruowana w Instytucie Elektrotechniki, emitująca światło w zakresach widmowych: czerwonym 68,5%, niebieskim 28,4% i bliskiej podczerwieni 3,1% (LED I) oraz lampa LED GrowBox emitująca światło czerwone i niebieskie 8:1 (LED II). Ze względu na wrażliwość mikrosadzonek początkowo rośliny cieniowano tak by natężenie napromienienia wynosiło 50 µmol m-2s-1, natomiast po 3 tygodniach zwiększono je do poziomu 100-120 µmol m-2s-1. Wszystkie rośliny nawożono identycznie płynną pożywką nawozową zawierającą makro i mikroskładniki. Wzrost i rozwój mikrosadzonek oceniono po 7 tygodniach aklimatyzacji. Zastosowane do doświetlania lampy LED wpłynęły bardzo korzystnie na wzrost mikrosadzonek truskawki. Mikrosadzonki doświetlanie lampami DAPLON-plus/2011 (LED I) miały największą świeżą masę, powierzchnię liści oraz najdłuższe korzenie. Nieznacznie słabiej rozwiniętą część nadziemną miały rośliny doświetlane drugim wariantem lamp, LED II. Rośliny doświetlane lampami LED wytworzyły więcej korzeni oraz miały grubsze szyjki korzeniowe niż doświetlanie lampami HPS.
EN
The effect of artificial lighting, using HPS and LED lamps during acclimatization of strawberry was evaluated. Unrooted strawberry plantlets ‘Pink Rosa’ obtained from in vitro laboratory were planted into growing media consisted of mineral wool granulates, water repellent and water absorbent (50:50 v/v). Plantlets were grown in growth chambers, with high humidity (80-90%), temp. 20-22°C and with artificial lighting using HPS (400 W) and LED lamps, photoperiod 16/8 h (day/night). Two types of LED lamps were used: LED I (Daplon-plus/2011 - emitted, red, blue and far red diodes at ratios 68,5%, 28,4% and 3,1%, respectively) and LED II (LED GrowBox – emitted red and blue light at ratios 8:1). Quantum irradiance was maintained at the same level in all treatments: 50 µmol m -2 s-1 during the first 3 weeks and later on 100-120 µmol m -2 s-1. All plants were fertigated twice a week using the same nutrient solution, contained macro and microelements. Plants were evaluated after 7 weeks of acclimatization. Both LED lamps used in this experiment resulted in greater weight, higher leaf area and better root development comparing to plantlets grown with HPS lamps.
W artykule podano wyniki analizy możliwości zastosowania półprzewodnikowych źródeł światła (LED) w doświetlaniu wybranych gatunków sadzonek roślin. Przedstawiono wybrane zagadnienia z zakresu doświetlania upraw szklarniowych światłem sztucznym z uwzględnieniem aspektów fotosyntetycznych i fotomorfogenetycznych. Scharakteryzowano badania przeprowadzone w Instytucie Elektrotechniki i Instytucie Ogrodnictwa. Do badań wykorzystano opracowany model oprawy LED o widmie w zakresie światła niebieskiego, czerwonego oraz promieniowania bliskiej podczerwieni. Artykuł zawiera opis tej oprawy wraz z przedstawieniem jej podstawowych parametrów fotometrycznych i elektrycznych. W czterotygodniowym eksperymencie badawczym wykazano, że zastosowanie tej oprawy do doświetlania sadzonek roślin może prowadzić do wymiernego zmniejszenia kosztów eksploatacyjnych w porównaniu z obecnie stosowanymi w tym zakresie lampami sodowymi.
EN
The article analyzes the applicability of semiconductor light sources (LED) for illumination of selected plant seedlings. Few chosen problems of supplementary artificial light illumination of greenhouse spices including photosynthetic andmphotomorphogenetic aspects were presented. The studies were performed in Electrotechnical Institute and Horticulture Institute. They were based on the application of LED lamp model of blue, red as well as infrared spectrum. The basic photometric and electical data of the lamp were stated. The four weeks research experiment proved the measurable reduction of operating costs of proposed LED application In comparison with currently used for this purposes HPS lamps.
Ukorzenione sadzonki roślin rabatowych: fuksji 'Beacon' oraz irezyny 'Shiny Rose' uprawiano zimą w szklarni stosując doświetlanie lampami sodowymi (400 W) i LED (zestaw oświetleniowy DAPLON-plus/2011 skonstruowany w Instytucie Elektrotechniki, emitujący światło w zakresach: niebieskim, czerwonym i bliskiej podczerwieni). Doświetlanie stosowano w godzinach 6-18, wyłączając je, gdy natężenie naturalnego promieniowania docierającego do roślin było wyższe niż 200 W m-2. Rośliny kontrolne uprawiano bez doświetlania. Dla obydwu doświetlanych kombinacji natężenie napromieniowania mierzone na poziomie łanu liści wynosiło 150-190 ?mol m-2 s-1. Wybrane parametry wzrostu roślin (wysokość, rozkrzewienie, świeżą i suchą masę) oceniono po 6 tygodniach wzrostu. Uzyskane wyniki wskazują, że obydwa gatunki doświetlane lampami LED były bardziej zwarte, wytworzyły mniej pędów bocznych oraz miały mniejszą powierzchnię liści. Świeża i sucha masa nadziemnej części irezyny i fuksji była najwyższa w przypadku doświetlania światłem sodowym. Najniższe wartości analizowanych parametrów wykazano w przypadku roślin kontrolnych, niedoświetlanych.
EN
Rooted cuttings of fuchsia 'Beacon' and iresine 'Shiny Rose' were cultivated in greenhouse during winter months (November, December). Supplemental lighting was applied from 6 do 18 using High Pressure Sodium Lamps (HPS, 400 W) or LED lamps (DAPLON-plus/2011, model elaborated in Electrotechnical Institute, Warsaw). Lamps were switched off when natural irradiation was higher than 200 W m-2. Control plants were grown in natural light conditions - without supplemantal lighting. For both treatements with supplemental lighting light intensity on plant canopy was 150-190 ?mol m-2 s-1. The growth parameters (plant height, branching, fresk and dry weight) were evaluated after 6 weeks of cultivation In greenhouse. Obtained results showed that both bedding plants iresine and fuchsia grown with LED lamps were more compact, with shorter side shoots and with lower leaf area. Fresh and dry weight of iresine and fuchia were the highest in conditions with HPS lamps. According to expectations the control plants, grown without supplemental lighting, had significantly shorter stems with less side shoots, the lowest fresh and dry weights and the lowest leaf area. Plants grown with supplemental ligting using HPS and LED lamps,had higer chlorophyll content in leaves (expressed as CCM and SPAD values), comparing to control plants.
Rośliny pomidora uprawiane w szklarni w okresie jesienno-zimowym (listopad - grudzień) doświetlano przy pomocy lamp sodowych lub LED (diody emitujące światło czerwone, niebieskie oraz w zakresie bliskiej podczerwieni). Kombinację kontrolną stanowiły rośliny rosnące w warunkach naturalnego światła. Prowadzono pomiary intensywności wymiany gazowej oraz natężenia zielonej barwy liści (względna zawartość chlorofilu). Po zakończeniu doświadczenia wykonano analizę budowy morfologicznej roślin mierząc masę organów roślinnych, wysokość roślin, średnicę pędu oraz powierzchnię liści. Doświetlanie roślin spowodowało zwiększenie natężenia wymiany gazowej i zawartości chlorofilu w liściach a także intensywniejszy wzrost. Ponadto wykazano zróżnicowanie pomiędzy roślinami z kombinacji doświetlanych. Rośliny doświetlane przy pomocy diod elektroluminescencyjnych były wyższe, miały większą masę, a w ich liściach stwierdzono więcej chlorofilu w porównaniu kombinacją, w której użyto lamp sodowych.
EN
The objective of the study was to evaluate the physiological response and growth of tomato transplants grown under different light treatment. During cultivation period (November - December), the transplants received supplemental artificial lighting provided by standard high-pressure sodium lamps (HPS) or high-power solid state lighting modules with red, blue and far red LEDs. Quantum irradiance in both combinations was maintained at the same level. The third group of plants (control combination) was grown under the natural light (without supplemental lighting). The following measurements were taken: leaf gas exchange (net photosynthesis and transpiration rate), leaf greenness index (relative chlorophyll content) and the most important morphological parameters (fresh weight of plant organs, leaf surface area, plant height). The results showed that supplemental illumination using LED or HPS light sources affected growth and physiological responses of tomato plants. The higher rates of gas exchange and leaf greenness index as well as enhanced growth were found in the plants grown under conditions of artificial lighting (compared to control ones). Additionally, significant differences (as a result of light spectral quality) were found between the plants lighted with HPS lamps or LED modules. LED lighting resulted in the stem elongation, greater weight of plant organs and higher chlorophyll content in the leaves. The obtained results proved that HPS lamps can be replaced by LEDs in greenhouse lighting systems. However, much work still has to be done to optimize lighting spectrum of LED modules for the cultivation of the specific crop species.
The investigation aimed at examining the changes in growth and photosynthetic activity of greenhouse-grown cucumber plants subjected to various fertilization regimes. The plants were subjected to the following treatments: standard fertilization with nutrient solution (control), foliar treatments with two fertilizers (complete or nitrogenous), without any fertilization (non-fertilized plants). The plants without fertilization were supplied with water only. Lack of fertilization resulted in the reduction of net photosynthesis and leaf chlorophyll content. The lowest rates of photosynthesis and leaf chlorophyll content were observed in the non-fertilized cucumber plants. Also, retardation in plant growth was evident in this group of plants as a result of nutrient deficiency. Foliar application of complete fertilizer (Agroleaf Power Total) had a pronounced effect on photosynthesis and growth of cucumber plants. On the other hand, the plants sprayed with nitrogenous fertilizer (Basfoliar 36 Extra) assimilated with low intensity, and their vigor did not differ significantly from that recorded for plants supplied with water only (non-fertilized).
PL
W dooewiadczeniu szklarniowym oceniono wzrost i aktywnooeć fizjologiczną rooelin ogórka w reakcji na zastosowane nawożenie. Kombinacje dooewiadczalne obejmowały rooeliny nawożone dokorzeniowo (fertygacja pożywką płynną), rooeliny nienawożone w trakcie trwania uprawy oraz rooeliny nawożone dolistnie jednym z dwóch nawozów: wieloskładnikowym (zawierającym makro i mikroelementy) lub azotowym (zawierającym azot i mikroelementy). Rooeliny nienawożone zasilane były tylko wodą. Najmniejsze natężenie fotosyntezy i zawartość chlorofilu w lioeciach wykazano w przypadku roślin nienawożonych. U tej grupy rooelin stwierdzono także najsilniejsze zahamowanie wzrostu. Spośród zastosowanych nawozów dolistnych, wyższą skuteczność wykazano w przypadku nawozu wieloskładnikowego. U roślin opryskiwanych tym nawozem stwierdzono większą zawartość chlorofilu w liściach oraz wysokie wartosci fotosyntezy netto. Rośliny traktowane nawozem wieloskładnikowym charakteryzowały się także bardziej intensywnym wzrostem.
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