Influence of exogenous tryptophan application on production and carotenoids of Calendula officinalis under drip irrigation treatments

Calendula officinalis L. is primarily cultivated as cut flowers plant and also regarded a medicinal with variety of therapeutic uses. Irrigation management results in reduction irrigation requirements, water saving conservation. Tryptophan has major role improving stress tolerance to environmental stresses such deficiency. This study investigated the response C. under drip system number times week-1 tryptophan foliar application two successive seasons. Three treatments (once, twice three week-1) were used main plots four (0, 15, 30 45 mg l-1) applied subplots replicates. Increasing from once showed highest values growth parameters, while week decreased them lower than those week.