Effect of salicylic acid on yield and osmolate content of radish (Raphanus sativus L.) at drought stress condition

Possibility of reducing drought stress adverse effects on yield and osmolate content of radish (var. Radish cherry bell) by application a plant growth regulator, salicylic acid, was studied in Shiraz Branch, Islamic Azad University, Fars province, Iran in 2012. Experiment was carried out as factorial based on a completely randomized design (CRD) with three replications under a long-term drought stress condition (45 days). Radish seeds were planted in pots with sandy-clay soil and drought stress was applied after two leaf stage. Factors were drought stress at three levels of one-day (normal), three-days (mild stress) and five-days (severe stress) irrigation intervals and salicylic acid at three levels (0, 1 and 2 mM). Yeild traits including length, diameter and weight of hypocotyl (under ground eatable part) and osmolates (prolin and soluble carbohydrates) were measured. The results showed that interaction effect of drought stress and salicylic acid was significant on all the studied traits. Sever stress condition caused a considerable reduction in hypocotyl length and diameter. Foliar application of salicylic acid 2 mM caused higher osmolate rates and it reduced the adverse effect of drought stress on radish yield.