Effect of Water Deficit Stress and Foliar Application of Maternal Plant on Germination Characteristics of Three Barley (Hordeum vulgare) Cultivars

Barley is the fourth largest cereal crop in the world and the second cereal crop in Iran in supplying food needs. Considering population growth and food shortages, it is important to look at ways to increase production. Seeds of higher quality and vigor emerge better when exposed to biotic and abiotic stresses and have stronger seedlings with higher vigor. It seems that one of the appropriate strategies for reducing or moderating the effect of stress on yield is foliar application with micronutrients which can also affect germination and vigor of the produced seeds. For this purpose, the effect of water stress and foliar application on germination characteristics and vigor of barley seeds was investigated. 

A factorial experiment was carried out based on CRD with four replications on the seeds resulted from a field experiment at Isfahan Kaboutarabad Agricultural Research Station, during the cropping year of 2018-19.  The main factors was foliar application at five levels: no foliar application(water use), zinc sulfate (0.5%), potassium sulfate (0.5%) and salicylic acid (1.5 mM), and superoxide dismutase (3 mg/liter) at the start of tillering for three times at seven day intervals and the sub-factor was genotypes was Goharan (drought tolerant), Mehr (salt-tolerant) and Armaghan (stress-sensitive). After harvesting, germination traits were evaluated.

Foliar application of maternal barley plant at the late season drought stress had a significant effect on root and shoots length, root and shoot dry weight, length and weight vigor indices, allometric coefficient and germination uniformity of seed. Also among the studied cultivars in late season irrigation cut off conditions, Goharan cultivar had a better shoot and root development (seedling vigor weight index) and higher seed germination uniformity.

Foliar application of potassium sulfate and zinc sulfate on different barley cultivars resulted in favorable metabolic conditions in seed and due to better root development and higher dry weight than stem development and as a result, higher allometric coefficient and better establishment under late season drought stress, may provide better growth conditions under drought stress conditions.

Goharan barley cultivar responds more positively to foliar application under late season drought stress conditions. Foliar application of potassium sulfate, zinc sulfate and super oxidase superoxide on Goharan cultivar maternal plant under late season drought stress condition led to the highest seedling root length, root dry weight and shoot dry weight.