M.A. Thesis:

Effect of sodium nitroprusside (SNP) time application on physiological characteristics of Sweet corn seedlings under salinity stress

To evaluate the effect of foliar application of Sodium nitroprusside on physiological characteristics of sweet corn under salt stress a factorial experiment in completely randomized design with three replications was conducted in Islamic Azad University of Sabzevar. Factors were Sodium nitroprusside time application with 200 ppm concentrations (vegetative, reproductive and vegetative + reproductive) and salinity (0,3,6,9 dS m). The results showed that increasing salinity levels from 0 to 9 dS m decrease the height 31.81%, plant dry weight 34.34% , the number of ear 46.34%, chlorophyll a 30.54%, chlorophyll b 55.81%, chlorophyll index 40.86%, carotenoid 37.40% total chlorophyll and the amount of potassium 54.86% and increased the amount of sodium 63.86% and potassium ratio 17.82. Two times application Sodium nitroprusside in vegetative and reproductive stage had maximum height, plant dry weight, ear number, chlorophyll a, chlorophyll b, total chlorophyll, chlorophyll and foliar potassium in the reproductive stage had higher levels of carotenoids and sodium to potassium ratio. Overall the results indicated that sweet corn is sensitive to salinity and cannot tolerate salinity more than 6 dS m. at Low salinity condition Sodium nitroprusside foliar application in vegetative + reproductive stage and in high salinity level once in the vegetative stage can somewhat reduce the effects of salinity.

Keywords: salinity, sodium nitroprusside, sweet corn, chlorophyll