Effects of Foliar Spraying with Salicylic acid and Putrescine on Growth Characteristics and Yield of Summer Savory (Satureja hortensis L.)

Summer Savory (Satureja hortensis L.) is an annual, herbaceous plant belonging to the Labiatae family. This plant is most often used as a culinary herb, but it also has marked medicinal benefits, especially upon the whole digestive system. The most important components of S. hortensis include volatile oils, phenolic compounds, flavonoids and phenolic acids, tannins, mucus, resins, carotenoids and mineral components. Plant growth regulators are used to improve the quality and quantity of medicinal plant production. Salicylic Acid is one of this PGRs that involved in seed germination, photosynthesis, Stomatal opening and closure, Membrane Permeability, Ions Absorption and transmission and other growth processes. Polyamines are ubiquitous low-molecular-weight aliphatic amines that are involved in regulating plant growth processes. The most commonly found polyamines in higher plants, putrescine (Put), spermidine (Spd) and spermine (Spm) may be present in free, soluble conjugated and insoluble bound forms. It has been demonstrated that PAs are important for the normal course of diverse plant ontogeny processes such as cell division and elongation, organogenesis and somatic and zygotic embryogenesis.
This experiment was conducted in factorial based on a randomized complete block design with three replications in Karaj, Iran. Foliar spraying with SA (1, 2 and 3 mM.l) and Putrecine (50, 100, 150 and 200 mg l-1) was performed in thrice in Savory growth period. Spraying was performed at 21, 35 (Budding Phase) and 56 (flowering initiation phase) day after seed germination. In flowering stage, some morphological traits such as plant height, weight, yield, canopy diameter, stem diameter, leaf area, essential oil content and efficiency were measured.
Analysis of variance showed that the effects of salicylic acid and putrescine spraying on plant height, canopy diameter, stem diameter, number of axillary stems, foliage dry weight, foliage yield, flower dry weight, number of leaves, leaf dry weight, leaf yield, leaf area index (LAI), number of inflorescence, dry weight of inflorescence, total chlorophyll content, chlorophyll a and b content, essential oil content, yield and efficiency was significant (P This study revealed that foliar application of SA and putrescine significantly affected the morphological, physiological and biochemical traits of Satureja hortensis. Thus, it can be used as a plant growth regulator for yield and essential oil content improvement in field production of this plant.