RESPONSE OF Cyperus alternifolius L. PLANT TO SOME ANTITRANSPIRANTS AND IRRIGATION WATER LEVELS

Rezumat

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.