The purpose of the present study was to determine whether water deficit affects cold hardiness of rhododendron ‘Catawbiense Boursault’, ‘Lee’s Dark Purple’, ‘Prinz Karneval’ and ‘Old Port’ shrubs. Plants were grown in unheated greenhouse and for 14 weeks from June to mid-September were subjected to six irrigation treatments. In the end of September shrubs were left in an unheated greenhouse or planted into the ground and at the beginning of each month from December to March freezing tolerance tests were performed. The results showed that in all rhododendron cultivars the highest cold hardiness was noted in January and February, lower in March but the lowest in December. Application of four-week water deficit period during summer especially between the first and the second vegetative growth may improve the frost resistance of Rhododendron shrubs.
Woody cuts are portions of woody ornamentals used for floral or decorative purposes. Some species of wild roses, because of the decorative fruits (hips) can be used for this purpose. The aim of this study was to evaluate the usefulness of Rosa Carolina, R. filipes, R. multiflora and R. virginiana for commercial growing of cut branches for floral arrangements. To assess flower bud formation and fruit production on the current or previous wood, half of the plants in the experiment were pruned annually to a height of 10 cm. Production data regarding shoots length, yields and decorative value for four Rosa species are presented over a three-year study. The most decorative shoots with hips were produced by unpruned R. multiflora shrubs, which had the most uniformly coloured red fruits (an average of 20 on a single shoot), and the hips were small (0.3 g). The fruits were mainly on the lateral shoots, whose average length was 22 cm. This species is also distinguished by a very small number of spines on the shoots, with some shoots completely free of spines, which is a very advantageous feature for using R. multiflora in floral arrangements. Yield and morphological characteristics of the fruit-bearing shoots of R. filipes were similar to those of R. multiflora, but the yields in the individual years of this study were different, and the colouring of the fruits in clusters was greatly extended in time. Unpruned shrubs of R. Carolina and R. virginiana produced 2-3 times fewer fruit-bearing shoots, with larger fruit, than R. multiflora. The treatment of the annual autumn pruning adversely affected flowering and fruiting of each species of rose.
The aim of this study was to analyze the physiological and morphological response of Syringa meyeri ‘Palibin’ to different levels of irrigation and to evaluate regulated deficit irrigation (RDI) as a possible technique for saving water in nursery production and promoting of flowering. Plants were grown in 3 liter containers in an unheated greenhouse and were subjected to six irrigation treatments for 18 weeks from the beginning of June to mid-October 2011. A drip irrigation system was used. Irrigation treatments were established on the basis of evapotranspiration (ETp). Three constant irrigation treatments were used: 1) 1 ETp; 2) 0.75 ETp; 3) 0.5 ETp, while the other three with irrigation varying between phases were as follows: 4) 1–0.5–1; 5) 1–0.25–1; and 6) 0.5–1–0.5 ETp. The 0.75 ETp and 0.5 ETp irrigation regimes adversely affected the growth and visual quality index of plants as well as they resulted in reduced leaf conductance, transpiration, maximum quantum efficiency of photosystem II (Fv/Fm) and CCI (chlorophyll content index). Plants grown under the 1–0.5–1 ETp regime had the same morphological parameters as plants grown under the 0.5 ETp treatment. A further reduction of water quantity supplied to plants in the 1–0.25–1 ETp regime resulted in further deterioration of the visual quality index of plants. In this study, the quality index of plants exposed to 0.5–1–0.5 ETp was similar to control plants (1 ETp). These plants were lower, more compact, and had smaller leaves than control plants. The irrigation regimes imposed in this study had no significant effect on the number of floral buds formed in relation to the control regime, except for 1–0.25–1 ETp where this number decreased.
Badano wpływ dwóch szczepionek endomikoryzowych (Endomix i Endorize-mix) oraz Eko-kompostu (0; 10 i 20% v/v) na wzrost krzewów pięciornika krzewiastego Potentilla fruticosa ‘Gold Drop’ uprawianych w pojemnikach oraz nawożonych nawozem mineralnym Osmocote Standard 5-6M (w dwóch dawkach: 1,5 oraz 3 g∙dm-3. Badania przeprowadzono w latach 2007-2008. W każdym sezonie wegetacyjnym oceniano wysokość roślin, masę wytworzonych pędów, liczbę kwiatów, stopień zasiedlenia systemu korzeniowego przez grzyby endomikoryzowe. Przeprowadzone badania wykazały, że krzewy pięciornika krzewiastego ‘Gold Dropʼ uprawiane w podłożu z dodatkiem Eko-kompostu oraz szczepionek mikoryzowych szybciej uzyskują rozmiary handlowe, są wyższe, mają większą masę pędów oraz wcześniej zakwitają. Najwyższy stopień zasiedlenia systemu korzeniowego przez grzyby endomikoryzowe obserwowano w drugim roku uprawy.