Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Dynamics of photosynthetic and oxidative stress parameters of two spinach species after short-term low UV-B radiation effect

100%
Januskaitiene I., Sakalauskiene S.
Acta Scientiarum Polonorum. Hortorum Cultus
|
2019
|
tom 18
|
nr 1
This work aimed to underline the dynamics of photosynthetic and oxidative stress parameters of ‘Matador’ and ‘Andromeda’ spinach species after short-term 1 and 2 kJm–2 UV-B radiation effect. When plants reached 3–4 leaves growths stage, the exposure to 1 kJm–2 and 2 kJm–2 UV-B radiation was done once for 68 and 136 minutes, respectively. The photosynthetic and oxidative stress parameters were determined 2, 24, 48 and 72 hours after exposure. The stimulating effect of UV-B emerged on the 3rd day after exposure. The positive effect of UV-B was more pronounced for ‘Matador’. The highest DPPH radical-scavenging capacity and the highest concentration of α-tocopherols were detected 24 hours after 2 kJ UV-B exposure, but the decrease in photosynthetic rate was the highest as well. Meanwhile, on the 3rd day after 1 kJ UV-B exposure, the indicators of oxidative stress of ‘Matador’ decreased, and the photosynthetic rate increased. This study highlights that low UV-B radiation acts as an eustress, by awaking positive changes in photosynthetic and oxidative stress parameters of spinach.
2
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Cultivation of sweet pepper (Capsicum annuum L.) transplants under high pressure sodium lamps supplemented by light-emitting diodes of various wavelengths

51%
Bagdonaviciene A., Brazaityte A., Virsile A., Samuoliene G., Jankauskiene J., Sirtautas R., Sakalauskiene S., Miliauskiene J., Marockiene N., Duchovskis P.
Acta Scientiarum Polonorum. Hortorum Cultus
|
2015
|
tom 14
|
nr 6
In greenhouses, artificial lighting is applied in winter and early spring as sup-plementary light source to increase photosynthesis and plant growth. The objective of this study was to evaluate the cultivation of sweet pepper transplants under LED lamps that were developed to supplement HPS lamps used in greenhouses. The experiments were carried out in the greenhouses at the Lithuanian Research Centre for Agriculture and For-estry Institute of Horticulture. Sweet peppers (Capsicum annuum) L. cultivar ‘Reda’ and the hybrid ‘Figaro’ F1 were used for investigation. Four types of solid-state lamps were used with light-emitting diodes (LEDs) with peak emissions at blue 455 nm and 470 nm, cyan 505 nm, and green 530 nm. PPFD of each type of LED lamp was 15 μmol m-2 s-1, and the PPFD of HPS lamps was 90 μmol m-2 s-1. The reference transplants were grown under the illumination of HPS lamps (110 μmol m-2 s-1). The photoperiod of artificial lighting was maintained at 18 hours. Our experiments revealed different responses to sup-plemental LED lightings between the cultivar and the hybrid. The supplemental 470 nm illumination with HPS lamps mostly resulted in increases in the following areas: leaf area, fresh and dry weight, and the photosynthetic pigment content of the sweet pepper ‘Reda’ transplants. A similar positive effect was determined using supplemental 455 and 505 nm LED lights. However, the supplemental green 530 nm LED lights had no effect on growth, and they inhibited the development of the sweet pepper ‘Reda’ transplants. The HPS light had a positive effect on the growth parameters of the ‘Figaro’ F1 transplants, but all of the supplemental LED lights suppressed their growth and development
3
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Impact of CO2 on quality of baby lettuce grown under optimized light spectrum

51%
Sirtautas R., Samuoliene G., Brazaityte A., Sakalauskaite J., Sakalauskiene S., Virsile A., Jankauskiene J., Vastakaite V., Duchovskis P.
Acta Scientiarum Polonorum. Hortorum Cultus
|
2014
|
tom 13
|
nr 2
The cost and yield are two the most important criteria in agriculture by which optimization of environmental factors are needed to carry out. In the present study, we investigated the efficient lighting spectrum and elevated CO2 concentration for cultivating healthier plants more rapidly. One of the aims of our study is to optimize LEDs light spectrum for healthier vegetable production in greenhouses and maximum economical benefits for growers. The impact of elevated carbon dioxide (CO2) concentration on antioxidant and nutritional properties of green leaf ‘Multigreen 3’ and red leaf ‘Multired 4’ baby leaf lettuce (Lactuca sativa L.), grown under optimized light spectrum was investigated. CO2 concentrations of 0.963 g · dm-3and 1.938 g · dm-3 were maintained in the growth chambers. Lettuce was grown under four wavelength (640, 455, 660 and 735 nm) light-emitting diode based (LED) illumination. Under 0.963 g · dm-3 CO2 conditions, ‘Multired 4’ lettuce represented higher antioxidant value due to higher ascorbic acid, anthocyanin, tocopherol contents and higher sucrose concentration, as compared to ‘Multigreen 3’ lettuce. Higher CO2 concentration (1.938 g · dm-3) had uneven effect on the quality of both baby leaf lettuce cultivars. Red leaf lettuce reacted to the higher CO2 level by lowered D tocopherol, ascorbic acid concentrations and significantly higher glucose contents in their leaves, when green leaf lettuce – contrarily – contained higher ascorbic acid and D tocopherol concentrations under 1.938 g · dm-3 of CO2.
4
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Effect of supplemental UV-A irradiation in solid-state lighting on the growth and phytochemical content of microgreens

42%
Brazaityte A., Virsile A., Jankauskiene J., Sakalauskiene S., Samuoliene G., Sirtautas R., Novickovas A., Dabasinskas L., Miliauskiene J., Vastakaite V., Bagdonaviciene A., Duchovskis P.
International Agrophysics
|
2015
|
tom 29
|
nr 1
In this study, we sought to find and employ positive effects of UV-A irradiation on cultivation and quality of microgreens. Therefore, the goal of our study was to investigate the influence of 366, 390, and 402 nm UV-A LED wavelengths, supplemental for the basal solid-state lighting system at two UV-A irradiation levels on the growth and phytochemical contents of different microgreen plants. Depending on the species, supplemental UV-A irradiation can improve antioxidant proper­ties of microgreens. In many cases, a significant increase in the investigated phytochemicals was found under 366 and 390 nm UV-A wavelengths at the photon flux density (12.4 μmol m-2 s-1). The most pronounced effect of supplemental UV-A irradiation was detected in pak choi microgreens. Almost all supplemental UV-A irradiation treatments resulted in increased leaf area and fresh weight, in higher 2,2–diphenyl–1–picrylhydrazyl free-radical scavenging activity, total phenols, anthocyanins, ascorbic acid, and α-tocopherol.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.