Vol. 54—2000 - NorthEastern Weed Science Society

Kentucky bluegrass was rated to have unacceptable color on the final two rating dates (July 27
and Aug 3).
At the 30% shade level ethephon treated peretUlial ryegrass color was rated lower than
untreated turfbut not below the level of acceptability of7. By July 27 only the perennial ryegrass
treated with ethephon at 3 oziM wasratedlower that untreated turf. On the final rating date (Aug
3) all perennial ryegrass (treated and untreated) was rated g.5 for color.
Whenperennialryegrasswas subjectedto a 55%shadeandratedforcolor only the 5 and
10 oziM rate of ethephon on July 13 were below that of untreated turf.
On July 13 all ethephon treated perennialryegrass under 73% shade hadcolor ratings
beluw untreated turf but not below a level of acceptability. On July 27 perennial ryegrass treated
at the 3 and 10 oziM rates ofethephon hadpoorer color than the untreated perennial ryegrass. By
the final rating date (Aug 3) all peretmial ryegrass treated with ethephon was rated to have poorer
color thanuntreatedturf.Regardlessof treatment,the colorratingsof the perennialryegrasswas
neverratedbelow the acceptablelevel.
After harvesting fresh weights ofperetUlial ryegrass grown at 55% shade on Aug 3 the
untreated turf produced 137.7 gramsof clippings which was significantly more than the perennial
ryegrass treated at any rate of ethephon (fables 2 and 3).
More shade/ethephon research should be conducted in the future.Although, some
interestingresultswere foundin these studies,the shadecanopies should be put in placejust after
turfgreenupin the springandtreatmentsbewithhelduntil the turfgrassis acclimatedto the
shadeenvironment.Thestudyshouldthenbeconductedforthe entiregrowing season.
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