M.A. Thesis:

ROLE of potassium in mitigation of salt stress in common Purslane ( portulaca grandiflora )

In salt stress conditions, the use of moderating substances such as potassium-containing fertilizers can reduce the negative effects of saline on yield and yield components of crops.. The objective of this study was to determine the effect of amount of potassium on yield and yield component of Common Purslane (Portulaca oleracea L.) grown under salt stress. The study was conducted in pot experiments under greenhouse conditions in Sabzevar branch, Islamic Azad university in 2016. a factorial experiment was carried based on completely randomized design with three replication. Factors were : amount of potassium (0. 150 and 300 kg k2o ha-1) as Solopotash form and salinity levels (0, 6, 9 and 12 ds/m). The results showed that increasing potassium amount in salt stress conditions increased the yield and yield components of Common Purslane and the highest height, number of lateral branches, number of capsule per plant, number of seeds per capsule, dry weight of plant, grain yield, potassium content and lowest The amount of sodium was obtained by consuming 300 kg ha-1. Salinity at 12 dS.m-1 level, 57.75% reduced plant height, 55.75% number of lateral branches, 37.27 capsules per plant, 68.56 seeds per capsule, 67.57% 1000 seed weight, 71% of plant dry weight, 47.21% grain yield, 41.91% potassium and increased 27.65% sodium content compared to control. In total, the results showed that till 9 dS.m-1 grain yield was not statistically significant and consumption of 300 kg.ha-1 was more suitable for reducing the effects of salinity stress.

Keywords: Potassium, Salinity, Common Purslane, yield