Evaluation of salicylic acid impact on growth and yield of onion plants under salinity stress conditions [electronic resource]

Includes bibliographic refrence

The present experiment was conducted at the Faculty of Agriculture, AL-Azhar University, Nasr
City, Cairo, Egypt, during the two winter seasons of2014-2015 and 2015-2016 to study the effect of
three saline levels in diluted agricultural drainage water (1000, 2000 and 3000 ppm) besides tap water
as a control (300 ppm) and three foliar salicylic acid (SA) concentrations (0.0, 1.0 and 1.50 mM) at
three times after 30, 45 and 60 days from transplanting and their interaction on the growth, yield and
bulb quality of onion (Allium cepa L.) cultivar Giza 20. The obtained results showed that plant height,
fresh weight, number of leaves, bulb fresh weight and diameter, leaf total chlorophyll, bulb dry weight
and relative water contents were significantly decreased with increasing the saline water levels from
1000 ppm up to 3000 ppm. On contrast, leaf proline content and bulb contents of T.S.S, ascorbic acid
significantly increased with increasing the saline water levels up to 3000 ppm if compared with the
control (300 ppm). On the other hand, data indicated that all the tested parameters were significantly
increased as a result the spray by SA at 1.0 mM compared with 1.5 mM concentration in the untreated
plants. The interaction of between treatments indicated that the application of SA at 1.0 mM was the
most effective in increasing the above mentioned characteristics under the different saline and the
control level. In this respect, it could be concluded that spraying onion plants with SA at the
concentration of 1.0 mM could reduce the adverse effects of saline irrigation water on growth and the
yield.

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