Karolina Mieszkalska

Warsaw University of Life Sciences – SGGW

Aleksandra Łukaszewska

Warsaw University of Life Sciences – SGGW


Geraniums are popular bedding plants used in urban public space and private gardens. Although well adapted to drought they often suffer from water stress, especially when planted into containers. In this trial, a response to periodical soil water shortage was tested on potted geraniums fertilized with a fertilizer containing 36% silicon and 20% phosphorus. During five weeks of culture under the experimental conditions, half of the greenhouse-grown plants were subjected to two 7 and 10-day periods without irrigation, separated by the periods of standard watering (7 and 10 days, respectively) (stressed plants) while the other half were irrigated (control plants). Half of the plants in each watering regime were planted into a growing medium enriched with the Si+P fertilizer. The
parameters of growth and flowering were evaluated on the 35th day and the leaves were analyzed for RWC, chlorophyll a+b and free proline contents. Water stress had little effect on plant height but decreased by one third the fresh weight of the above-soil plant parts. The number of flowers remained unaffected but the number of flower buds developed under the experimental conditions fell to 30% in plants subjected to stress as compared to the watered control. The application of the fertilizer enhanced plant growth regardless the watering regime but decreased flower numbers in both groups. However, this treatment positively affected development of new flower buds, especially in stressed geraniums, where the increase in bud number was nearly 8-fold relative to the non fertilized plants. The relative leaf water contents remained unaffected by the watering regime while the fertilizer increased RWC in both plant groups. Total chlorophyll contents doubled under stress, and were further increased by the fertilizer in both plant groups. Water deficit increased the free proline content in leaves by a third. However, in the non-stressed and fertilized plants it increased by 48% and remained unchanged in stressed fertilized plants. The experiment demonstrates that Si+P fertilization may mitigate the undesirable effects of water-stress in potted geraniums.


bedding plants, drought, growth, flowering, RWC, free proline, chlorophyll a b

Augé R.M., Stodola A.J.W., Moore J.L., Klingeman W.E., Duan X., 2003. Comparative dehydratation tolerance of foliage of several ornamental crops. Sci. Hort. 98, 511–516.
Barrs H.D., 1968. Determination of water deficit in plant tissues. Water Deficit and Plant Growth, Vol.1, Academic Press, New Dehli.
Bates L.S., Waldren R.P., Teare I.D., 1973. Rapid determination of free proline for water stress studies. Plant and Soil 39, 205–207.
Chyliński K.W., 2008. Reakcja roślin ozdobnych na warunki miejskie [Response of ornamental plants to urban conditions]. PhD Thesis, SGGW, Warszawa.
Chyliński W., Dziedzic J., 2005. Changes in ammonium and chlorophyll a+b contents in leaves of two bedding plants grown under drought stress. Biological Lett. 42, 207.
Chyliński K.W., Łukaszewska A., Kutnik K., 2007. Response of two bedding plants to drought. Acta Physiol. Plant. 29, 399–406.
Chyliński K.W., Łukaszewska A.J., 2008. Reaction of bedding ornamentals to drought stress. Ann. Warsaw Univ. Life Sci. – SGGW, Horticult. Landsc. Architect. 29, 39–44.
Gong H., Zhu X., Chen K., Wang S., Zhang C., 2005. Silicon alleviates oxidative damage of wheat plants in pots under drought. Pl. Sci. 169, 131–321.
Hattori I., Inanaga S., Araki H., An P., Morita S., Luxova M., Lux A., 2005. Application of silicon enhanced drought tolerance in Sorghum bicolor. Physiol Plant 123, 459–466.
Hu Y., Schmidhalter U., 2005. Drought and salinity: a comparison of their effects on mineral nutrition of plants. J. Plant Nutr. Soil Sci. 168, 541–549.
Jin J., Wang G., Liu X., Pan X., Herbert S.J., Tang C., 2006. Interaction between phosphorus nutrition and drought on grain field, and assimilation of phosphorus and nitrogen in two soybean cultivars differing in protein concentration in grains. J. Pl. Nutr. 29, 1433–1449.
Kavi Kishor P.B., Hong Z., Miao G.H., Hu C.A.A., Verma D.S.P., 1995. Overexpression of Δ1-pyrroline-5-carboxylate synthetase increases proline production and confers osmotolerance in transgenic plants. Plant Physiol. 108, 1387–1394.
Lichtenthaler H., Wellburn A.R., 1983. Determination of total carotenoids and chlorophylls a and b leaf extracts different solvents. Biochem. Soc. Trans. 603, 591–592.
Łukaszewska A., Porowska M., Chyliński W., 2008. Effect of drought and benzyladenine on scarlet salvia (Salvia splendens Sello) and geranium (Pelargoniom hortorum L.H. Bail.). Ann. Warsaw Univ. Life Sci. – SGGW, Horticult. and Landsc. Architect. 29, 45–52.
Ma J.F., 2004. Role of silicon in enhancing the resistance of plants to biotic and abiotic stresses. Soil Sci. Plant Nutr. 50, 11–18.
Nelsen C.E., Safir G.R., 1982. Increased drought tolerance of mycorrhizal onion plants caused by improved phosphorus nutrition. Planta 154, 407–413.
Pei Z.F., Ming D.F., Liu D., Wan G.L., Geng X.X., Gong H.J., Xhou W.J., 2010. Silicon improves the tolerance of water-deficit stress induced by polyethylene glycol in wheat (Triticum aestivum L.) seedlings. J. Pl. Growth Regul. 29, 106–115.
Sanchez-Blanco M.J., Alvarez S., Navarro A., Banon S., 2009. Changes in leaf water relations, gas exchange, growth and flowering quality in potted geranium plants irrigated with different water regimes. J. Plant Physiol. 166, 467–476.
Sawwan J., Shibii R.A., Swaidat I., Tahat M., 2000. Phosphorus regulates osmotic potential and growth of African violet under in vitro-induced water deficit. J. Plant Nutr. 23, 759–771.
Shen X., Zhou Y., Duan L., Li Z., Egrinyza Eneji A., Li J., 2010. Silicon effects on photosynthesis and antioxidant parameters of soybean seedlings under drought and ultraviolet–B radiation. J. Pl. Physiol. 167, 1248–1252.
Siddique M.R.B., Hamid A., Islam M.S., 2000. Drought stress effects on water relations of wheat. Bot. Bull. Acad. Sin. 41, 35–39.
Šircelj H., Tausz M., Grill D., Batic F., 2007. Detecting different levels of drought stress in apple trees (Malus domestica Borkh.) with selected biochemical and physiological parameters. SciHort.113, 362–369.
Ueda A., Kanechi M., Uno Y., Inagaki N., 2003. Photosynthetic limitations of a halophyte sea aster (Aster tripolium L.) under water stress and NaCl stress. J. Plant Res. 116, 63–68.
Wang W., Vincour B., Altman A., 2003. Plant responses to drought, salinity and extreme temperatures: towards genetic engineering for stress tolerance. Planta 218, 1–14.
Wang X., Wei Z., Liu D., Zhao G., 2011. Effects of NaCl and silicon on activities of antioxidative enzymes in roots, shoots and leaves of alfalfa. Afr. J. Biotech. 10, 545–549.
Yamada M., Morishita H., Urano K., Shiozaki N., Yamaguchi-Shinozaki K., Yoshiba Y., 2005. Effects of free proline accumulation in petunias under drought stress. J. Exp. Bot. 56, 1975–1981.


Karolina Mieszkalska 
Warsaw University of Life Sciences – SGGW
Aleksandra Łukaszewska 
Warsaw University of Life Sciences – SGGW



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