Evaluation of the impact of drought stress levels on yield and morphological traits of borage (Borago officinalis L)

Cultivation of medicinal herbs in the country can play an essential part in ensuring public health and employment and preventing the genetic erosion of valuable medicinal plant species due to unprincipled harvesting from their natural habitat as well as non-oil export. Thus, the present experiment was carried out in 2020-2021 on a farm located in Namin city seeking to evaluate the impact of drought stress levels on the yield and morphological traits of borage (Borago officinalis L). The experiment was conducted in completely randomized blocks with three iterations. The treatments included three levels of drought stress including al: control (no stress), a2: normal stress (irrigation at 70% FC), and a3: intense stress (irrigation at 40% stress). The traits evaluated in the present study included the number of leaves, plant height, the number of flowers, the number of branches, wet yield, dry yield, and dry flower yield. Results indicated that the studied variables differed significantly in terms of all the studied traits at 1% and 5% significance levels. Results revealed that treatment with 40% and 70% FC irrigation resulted in a (15.1 and 24.57%) and (17.16 and 21.12%) decline in wet and dry yields and a (5.12 and 18.71%) and (7.44 and 18.32%) decline in wet and dry flower yields, respectively. in other words, drought stress left a significant impact on the traits, indicating that borage is sensitive to water deficiency and suffers from reduced growth manifested through reduced plant height, wet weight, dry weight, and flower yield under drought conditions.