Effect of regulated deficit irrigation on growth, flowering and physiological responses of potted Syringa meyeri ‘Palibin’

Abstract

<p>The aim of this study was to analyze the physiological and morphological response of <em>Syringa meyeri </em>‘Palibin’ to different levels of irrigation and to evaluate regulated deficit irrigation (RDI) as a possible technique for saving water in nursery production and promoting of flowering. Plants were grown in 3 liter containers in an unheated greenhouse and were subjected to six irrigation treatments for 18 weeks from the be- ginning of June to mid-October 2011. A drip irrigation system was used. Irrigation treatments were established on the basis of evapotranspiration (ETp). Three constant irrigation treatments were used: 1) 1 ETp; 2) 0.75 ETp; 3) 0.5 ETp, while the other three with irrigation varying between phases were as follows: 4) 1–0.5–1; 5) 1–0.25–1; and 6) 0.5–1–0.5 ETp. The 0.75 ETp and 0.5 ETp irrigation regimes adversely affected the growth and visual quality index of plants as well as they resulted in reduced leaf conductance, transpiration, maximum quantum efficiency of photosystem II (Fv/Fm) and CCI (chlorophyll content index). Plants grown under the 1–0.5–1 ETp regime had the same morphological parameters as plants grown under the 0.5 ETp treatment. A further reduction of water quantity supplied to plants in the 1–0.25–1 ETp regime resulted in further deterioration of the visual quality index of plants. In this study, the quality index of plants exposed to 0.5–1–0.5 ETp was similar to control plants (1 ETp). These plants were lower, more compact, and had smaller leaves than control plants. The irrigation regimes imposed in this study had no significant effect on the number of floral buds formed in relation to the control regime, except for 1–0.25–1 ETp where this number decreased.</p>

Deficit irrigation strategies (PRD, SDI) and titanium nanoparticles improve water use efficiency and flower quality in greenhouse-grown cut roses

“…Under drought conditions, restricting vegetative growth to limit transpiration levels is one of the primary defense responses of the plant 49 , 50 . The literature also states that the PRD technique causes more abscisic acid (ABA) secretion in roots; it sends a message to close or limit the diameter of the stomata, which prevents excess water from escaping through the leaves 51 , 52 .…”