Changes in henna (Lawsonia inermis L.) morphological traits under different deficit irrigations in the southern Tunisia

Abstract

Henna plant belongs to continental oases where water shortage constitutes the essential limiting factors of its agricultural production. Lawsonia inermis L. (Lytraceae) is often exposed to severe drought stress in Gabes; a Tunisian arid region. The present study was carried out to evaluate the impact of water stress on the morphology of Tunisian henna plants. Thus, an experiment of four months was carried out under greenhouse at the Institute of Arid Region in Medenine, Tunisia. Henna was exposed to three different irrigation regimes, whereby the plants where irrigated to field capacity (control, T0), 50% of the control (moderate stress, T1) and 25% of the control (severe deficit irrigation, T2). Results showed that, leaf area (LA), leaf number and stem length of henna, decreased in response to the studied stress. The effect of water stress was clearly observed on those parameters. Moderate drought (T1) did not damage henna morphology, and the plants grew better than without water limitation (T0). Furthermore, the water stress-typical responses were shown as time and severity dependent in all the measured parameters. Indeed, lowest water availability treatment (T2) induced significant decrease in total number of leaves, as well as

Salinity-Induced Changes of Photosynthetic Performance, Lawsone, VOCs, and Antioxidant Metabolism in Lawsonia inermis L.

“…Conversely, an inhibition of growth parameters occurred at the highest salt level (150 mM) after only 20 days of treatment. A similar reduction of leaf number and leaf area was observed in henna plants subjected to drought stress [7] and to long-term salinity treatment [10].…”

“…Lawsone production is enhanced by high temperature and high light intensity [ 6 ]. Many reports have been conducted to analyze the growth condition of henna in order to achieve information on its ability to tolerate drought and salinity [ 7 , 8 , 10 ]. However, these authors excluded the examination of the influence of the stress for the production of lawsone.…”

“…Several studies have been carried out to underline the effect of some abiotic factors on germination, seedling growth, and morphological and physiological traits [ 7 , 8 ]. Drought stress is considered one of the main limiting factors of the henna cultivation that alters the growth, gas exchange parameters, and photosynthetic pigment contents proportionally with the intensity of water limitation [ 7 , 9 ]. L. inermis can overcome drought stress but not salinity [ 6 ] because it activates the reproductive phase when subjected to prolonged salt stress [ 10 ].…”

Alternative Irrigation Method as an Effective Technique for Rationalization of Irrigation with Foliar Fertilizer on Henna (Lawsonia alba, Lam.) Plants

“…Henna plants were able to tolerate water stress in the moderate stress (50% of the control) by adapting morphological mechanisms to counter drought damage. However, plants seem to be more sensitive to drought at (25% of the control) severe deficit irrigation stress, (Enneb et al, 2015).…”

“…Foliar fertilization method may be a good substitute to the predictable soil application to avoid the loss of fertilizers by leaching and thereby minimizing the ground water pollution, (Tomimori et al, 1995) There isn't enough information about water requirements and consumptive use for ornamental, medicinal and aromatic plants, especially in the North Nile delta region. Abovementioned reviews, according to drought sensitivity index, henna consider as a moderately tolerant plant to drought, (Enneb et al, 2015) and can be achieved overcome drought in these areas. On the other side, rationalization of irrigation water in agriculture sector is becoming a must to save water and reaches with the losses to the minimum level by decreasing the irrigation area in comparison with traditional irrigation method which always practices by local farmers.…”