Growth and Biochemical Characters of Basil (Occimum basilicum) in Response to Low Irrigation and UV-B

Abstract

Various basil cultivars in greenhouse can be cultivated round all year with the necessary growth conditions. Environmental stresses such as low irrigation and ultraviolet radiation are among the factors affecting the plant growth and development process. In the current study, five treatments for duration of ultraviolet radiation (0, 5, 10, 15, 20 minutes per day) and four irrigation levels (100, 75, 50, 30 % of field capacity) on two green and violet type of basil based on factorial in a completely randomize design experiment was conducted. The results showed that the duration of UV irradiation, low irrigation stress and their interaction effected morphological and biochemical responses of both basil cultivars. Measured traits such as leaf thickness, secondary metabolites, percent of essential oil, sodium and potassium elements content under UV treatments, low irrigation stress, and their interactions significantly increased compared to the control, but inter-nod decreased due to ultraviolet radiation, low irrigation stress and interaction effects. The amount of soluble sugars increased due to low irrigation stress (especially relatively severe low irrigation stress, 50% FC), but decreased due to high levels of UV treatments compared to the control, according to the result, UV radiation and low irrigation stress had shown synergistically stat together. The purpose of this study was to investigate the effects of UV light duration (280–320 nm), low irrigation stress, and the combined effects of UV light duration and low irrigation stress on morphological and biochemical responses of two basil cultivars.