Literature indicates that under drought, alkaline or high-salinity conditions, plants respond by reducing growth via systems involving alkalinisation of xylem sap, hormone signalling via abscisic acid and ethylene and other physical and physiological changes such as stomatal closure. Professor Kettlewell and Andrew Beacham of HAU investigated the effect of using high-pH and high-salinity treatments.
Applied as drenches, high-salinity treatments were found to be effective in reducing petiole length in flat leaf parsley and coriander. The overall biomass of plants was reduced at times by the saline treatments, suggesting more compact growth. Overall effectiveness and phytotoxicity of the treatments appeared to depend on environmental conditions and treatment regime. Phytotoxicity was very low or absent in winter months but increased into spring.
The project demonstrated that saline treatments have potential to reduce etiolation with no significant phytotoxic effects. Further work will be required to determine optimum treatment regimes across a range of herbs. However, this work may provide growers with additional control mechanisms to improve shelf life and plant quality in the future.
Horticultural Development Company
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