ISHS Acta Horticulturae 614: VI International Symposium on Protected Cultivation in Mild Winter Climate: Product and Process Innovation
GROWTH CONTROL BY MECHANICAL CONDITIONING IN SALVIA SPLENDENS SELLOW EX SCHULT |
| Authors: | P. Vernieri, S. Mugnai, F. Tognoni |
| Keywords: | Thigmomorphogenesis, brushing, shaking, impedance, Topflor®, abscisic acid, stomatal conductance |
| Abstract:
Seedlings growth is commonly controlled by chemical growth regulators, but recent legal regulations on the use of these products have caused wide changes on the practices for seedlings growth control. So, mechanical stress has been proposed as an alternative treatment for height control in some species. The aim of this study was to evaluate the efficacy of mechanical stress (brushing, shaking, impedance) on height control in Salvia splendens, one of the most widely diffused bedding plants, compared with the traditional chemical method (Topflor®). The use of a chemical growth regulator, Topflor®, was more effective than mechanical methods in height control in Salvia splendens, cv. Flamex 2000. In details, marked differences in stem height, total dry weight and leaf area among plants treated with Topflor® and control were statistically significant. Although control and all mechanical stress methods led to similar total dry weight, differences in some morphological parameters were observed: impedance and brushing significantly reduce plant height and leaf area, whereas shaking does not affect either plant size or leaf area. No significative differences were found in flower development among the treatments, in terms of both date of flowering and flower size. Moreover, abscisic acid synthesis at root level and its translocation to shoots did not seem to be affected by stress methods, suggesting no relationships among mechanical stress and chemical signalling originating from the roots. | |
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