Effect of fulvic and humic organic acids and calcium on growth and chlorophyll content of tree species grown under salt stress
Dendrobiology 2009, vol. 62: 47-53
Abstract: The use of salt to malt ice has definite effects on the environment. Some of these environmental effects are: soil erosion, environmental pollution, changes in mineral nutrition or general destruction of the physiological processes of plants. This use of salt has a negative impact on roadside vegetation and sustainability. The objective of the presented study was to investigate the effects of fulvic and humic organic acids as well as the calcium on growth and chlorophyll content of seven tree species grown under salt stress. Two year old seedlings of – Acer campestre, Aer platanoides, Acer pseudoplatanus, Acer tataricum ssp. ginnala, Ginkgo biloba, Platanus ×hispanica 'Acerifolia' and Tilia cordata were planted to plastic pots (2 dm3 vol). They were planted outdoors in a growing medium compound which had high sphagnum peat, grainy sand and composted pine bark. Salinity stress was maintained by irrigating plants with tap water containing 3.3 g NaCl/L H2O. Different organic fertilizers were used to redce the risk of nutritional stress caused by salinity. Salinity in the growing medium limited the growth of two maple species and littleleaf linden. In other species such A. campestre, A. tataricum ssp. ginnala, G. biloba there were no significant differences when compared to the control group of plants. Severe leaf damage was observed on A. paltanoides where leaf burning was seen on up to 30%of the leaf blade surface. The response to salinity of other species like A. pseudoplatanus, A. tataricum ssp. ginnala, and T. cordata was less evident. Humic organic acids applied alone to the growing medium improved the growth of all the maple species when compared to the control group. A calcium had the best effect on the growth of all tested trees except A. tataricum ssp. ginnala and G. biloba. The chlorophyll content index (CCI) differed according to the growing medium treatment and the species. The total CCI ranged from 9.62 for the control plants P. ×hispanica 'Acerifolia' to 52.64 for G. biloba which had been treated with a calcium. Application of organic fertilizers to the salt treated growing medium increased the CCI in many species.
Additional key words: chlorophyll content, salinity stress, ornamental trees