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Dendrometric evaluation of Helianthus annuus under water deficit conditions

Obročník Oliver, Bárek Viliam

Journal of Water and Land Development

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2023

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no. 59

50--53

EN

Drought is characterised as a recurring climatic phenomenon with prolonged duration, affecting land through below-average rainfall and often accompanied by high temperatures. When the available water falls below the optimum level, water deficit or water stress arises, disrupting normal plant processes. This condition poses challenges for plant growth and development as it hampers the internal water transport, induces stomatal closure, and limits access to photosynthetic resources. The study employed the annual sunflower as the experimental plant. The plants were cultivated in a controlled environment with a temperature ranging from 20 to 25°C and a humidity level of 55 to 60%, supplemented by MARS HYDRO artificial LED lighting set to a 12-h photoperiod. Radial changes in the plant stems were monitored using a DD-S type dendrometric sensor to measure radial fluctuations. The collected data were recorded in a dendrometric data logger DL 18. Data collection occurred at hourly intervals from February 20 to March 9, 2023. The nine plants were divided into three groups, each comprising three plants. All plants from groups 1 and 2 received irrigation at one-day intervals (group 1 - 80 cm3 per plant, group 2 - 40 cm3 per plant) and group 3 was not irrigated. Based on these findings, visible water stress was evident in the plants under experimental conditions. Consequently, continuous monitoring throughout the growing season will be essential to adjust the irrigation rate to meet the requirements of the plants.

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Ocena potencjału allelopatycznego rośliny inwazyjnej - nawłoci olbrzymiej (Solidago gigantea) w odniesieniu do gryki zwyczajnej (Fagopyrum sagittatum) oraz słonecznika zwyczajnego (Helianthus annuus)

Sekutowski T. R., Bortniak M., Domaradzki K.

Journal of Research and Applications in Agricultural Engineering

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2012

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Vol. 57, nr 4

86-91

PL

W badaniach własnych oceniano wpływ wodnych wyciągów sporządzonych ze świeżej masy liści i łodyg nawłoci olbrzymiej (S. gigantea) na zdolność kiełkowania i wzrost korzeni gryki zwyczajnej (F. sagittatum) oraz słonecznika zwyczajnego (H. annuus). Doświadczenie przeprowadzono z użyciem testu kiełkowania i wczesnego wzrostu roślin - Phytotoxkit. Testy obejmowały trzy niezależne serie doświadczeń laboratoryjnych, w każdej serii po trzy powtórzenia. Wodne wyciągi sporządzono ze 125, 250 oraz 500 g świeżej masy nawłoci olbrzymiej (S. gigantea) na 100 cm3 wody destylowanej. Obiekt kontrolny stanowiły pyłki, na które nanoszono jedynie wodę destylowaną. Uzyskane wyniki wykazały, że najsilniejszy efekt inhibicyjny w odniesieniu do zdolności kiełkowania oraz długość korzeni gryki zwyczajnej (F. sagittatum), stwierdzono po zastosowaniu 50% wyciągu. Natomiast najsilniejszy efekt w postaci stymulacji wzrostu korzeni słonecznika zwyczajnego (H. annuus), stwierdzono po zastosowaniu 12,5% wyciągu.

EN

In the laboratory experiments effect of the fresh mass of goldenrod (S. gigantea) leaf and stem water extracts on germination capacity and buckwheat (F. sagittatum) and sunflower (H. annuus) on root growth were determined. Test of germination and early growth - Phytotoxkit was used in experiment. The research covered 3 independent laboratory series, 3 repetitions in each series. Water extracts were prepared from 125 g, 250 g and 500 g of fresh mass of goldenrod (S. gigantea) and 100 cm3 of distilled water. Plates moistened of distilled water were control objects in these experiment. Data indicated that the highest inhibition effect on the germination capacity and buckwheat (F. sagittatum) root length was obtained after application on water extracts of 50%. The strongest effect in the form of sunflower (H. annuus) root growth stimulation was observed after application of water extract of 12.5%.

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Bioaccumulation of 137Cs and 60Co by Helianthus annuus

Horník M., Pipíška M., Vrtoch L., Augustín J., Lesný J.

Nukleonika

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2005

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Vol. 50,suppl.1

49-52

EN

The 60Co and 137Cs bioaccumulation by Helianthus annuus L. was measured during 9 day cultivation at 20 š 2°C in hydroponic Hoagland medium. Previous starvation for K+ and for NH4 + 2.2 and 2.7 times, respectively, enhanced 137Cs uptake rate. Previous cultivation in surplus of K+ ions 50 mmol.l 1 has no effect on 137Cs bioaccumulation rate. Both 137Cs and 60Co bioaccumulation significantly increase with dilution of basic Hoagland medium up to 1:7 for caesium and up to 1:3 for cobalt followed by mild decrease at higher dilutions. Root to shoot specific 137Cs radioactivity ratio (Bq.g 1/Bq.g 1, fresh wt.) increased with dilution from 1.46 to 9.6-9.8. The values root to shoot specific radioactivity ratio for 60Co were less dependent on the nutrient concentrations and were within the range 5.7 to 8.5. 137Cs was localized mainly in young leaves (30%) and roots (39%) and 60Co mainly in roots (67%) and leaves (20%). Obtained data showed less sensitivity of 60Co uptake by sunflower on nutrient concentration in hydroponic media.