This investigation was carried out in the open field at the experimental nursery of Ornamental
Plants and Landscape Gardening Res. Dept., Hort. Res. Inst., ARC., Giza, Egypt during 2015/2016 and
2016/2017 seasons to study the effect of different anti-transpirants (active dry yeast extract at 1, 2 and 3%,
calcium carbonate at 100, 200, 300 ppm and kaolin at 1, 2 and 3%) on umbrella plant (Cyperus alternifolius L.)
cultivated as a pot plant in 25 cm pots under different irrigation levels expressed as percentage of water holding
capacity (WHC) at 100, 75, 50 and 25%. The aim of this work was to reduce irrigation water quantity to a
considerable level without obvious reduction in the plant quality and its aesthetic value. Reducing irrigation
levels resulted in the lowering plant quality with increasing proline content (mg/g d.w.) in the plants. The effect
of irrigating at 75% WHC was close to irrigating at 100% WHC without great quality reduction in most cases.
Spraying with calcium carbonate (CaCO3) at 200 ppm or active dry yeast extract (ADY) at 3% resulted in the
highest values for the most studied traits. Combined treatment between irrigating at 75% of WHC and spraying
with CaCO3 at 200 ppm produced the highest values of plant height (cm), chlorophylls a, b, carotenoids contents
(mg/g f.w.) and total carbohydrates percentage. Such treatment came in the second order after the superior
combination comprised irrigating at 100% WHC without significant difference between them concerning stem
number/plant, stem diameter (cm), offset number/plant, fresh and dry weights of vegetative growth and
underground parts weight (g) and root length (cm). Our results indicate that irrigation water quantity could be
reduced by 25% without reduction in quality and atheistic value in umbrella plants planted in 25 cm pots via
irrigation at 75% WHC two times/week and spraying them with CaCO3 at 200 ppm monthly.