M.A. Thesis:

The effect of rate and application method of potassium on yield and yield components of Sunflower in saline condition

Potassium (K) plays an essential role in reducing the effects of salt stress in plants. Yield and yield components response of Sunflower to rate and application method of Potassium under saline condition was studied as out as split plot design based on randomized complete block design with three replications in Sabzevar Agriculture and Natural Resources Research center in 2015. Factors were: K rate (100 and 150 kg ha-1 K20 (Solopotash form(50% k20 and 18% S)) as the main plot and application method (100% at planting, 75% at planting +25% at vegetative stage, 50% at planting +50% at vegetative stage, 50% at planting+25% at vegetative stage+ 25% at flowering stage and control). Increasing of K level to 150 kg.ha-1 increased plant height, head diameter, seed per head, 100 kernel weight, seed yield and biological yield. K application as 100% in planting date had plant height, head diameter, seed per head, 100 kernel weight, seed yield and biological yield which didn’t significant difference with 75% at planting +25% at vegetative stage. The results obtained here suggest that 150 kg.ha-1 application (as Solopotash form) in planting date.

Keywords: Application method, Potassium rate, Salinity stress, Sunflower