'TIfway" hybrid bermudagrass ( Cynodon Iransvaalensis Burtt-Davy x C.
dacty/on ( L.) Per5. ) is a popular turigrass used in Egypt on a large scare. 'MIen this
grass is managed as a medium- to high· quality turf, frequent mowings are needed to
limit vegetative growth and seedhead emergence. Plant growth retardants offer Ihe
potential to reduce the number or mowings needed by turigtasses and accordingly
reduce the cost of turf maintenance. Therefore, a field experiment was conducted
during spring of Ihe two successive seasons of 2002 and 2003 to Sludy the effects' of
two different growth retardants on growth and quality of "Tifway' bermudagTss under
the Egyptian conditions. Threa weeks after planting rhe turf plugs, the ueated grasses
received once alther melluid(de at a rale of,4 mglblock (1x'm), paclobutrazol at a
rate of '10 mglblock, or mefluidide plus paclobutrazol at the previously mentioned
rates. Each treated block was sprayed individually with 5 fiters distilled water
containing the designated amount of growth retardants using a 5 liter semi'automated
hand sprinkler, Control blocks (untreated grasses) were sprayed with distilled water
only. Measurements on grass height, coverage percentage, clipping welghl,
quality and color of the tungrass were conduC\ed al the end of 3, 6 and 9 weeks alter
application with the plant growth retardants in addition to shoot and root weight atl,he
end of experiment to determine Ihe effects of mefluidide and paclobutrazot on grOWth
and quality of the used tungrass. The obtained results Showed that three weeks after apprtcation, mefluidjde
alone provided fast suppressive effects on grass height and shool growth, but
reduced quality. color, and the coverage percentage. Paclobutrazol alone, on the
othat hand was more efteclhle Ihan mefluIdlde In suppressing height and reducing
clipping dry weight with little effect on grass quality, color, and coverage percentage
after six wee\(s from application. Menuidide plus paclobutrazoi treatment gave fast
and best suppressive effect on grass height and shoot growth thrcugh01Jt the
experiment. This treatment reduced quality and color or 'Tlfway' bermudagrss dU~lng
the first three weeks after application, but grasses recovered their quality and color six
weeks after application until the end of the experiment. The results also showed t at
the effects of bOth grC'l'o't1h retaroants were minimIzed after nine weeks 01 applicatlbn.
At the end of experiment, mellu;dide alone produced the highest shoot and root dry
weights and the highest rooVshoot ratio among the three growth retardant tteOltments. These resutts were obtained (rom using a singte application, and Mure
experiments are needed to study the effect of these growth retardants using multi Ie
applications on a well established turfgrass slar.d.