Vol. 16—1962 - NorthEastern Weed Science Society

Pre-emergence Crabgrass Control
A number of chemicals are now !lva.11able for the pre-emergence controlof
crabgrass (Dig te~ ischaemum, 12.;.sanguinalis). This paper reports the
results of our 19g1 trials in which ocemercf.al, f'ormuJ.ations of sevendif-·
ferent chemicals were observed for their effectiveness in the pre-emergence
control of crabgrass.
MA.TERIAUlAND METHODS
The experimental plots ,,'erelocated at the Cornell Turfgrass Research
~lots, Nassau County Park, East. Hempstead, Long Ioland.
Two separate areas were selected for these trials. one area, designated
"poor turf," consisted of a thin stand of native bentgrass and loed.
fescue and was selected because of its reliability of crabgrass infestat:tbn.­
'i.'he experimental design was a complete randomized block with seven treat':'­
ments in quadruplicate on 7 x 7' plots. Four plots served as checks. ~
area was fertilized following application of the chem1caJ.s excep-t; for plots
tre,ated with the arsenical-fertilizer formuJ.ation (Pax). All the chemicals
were watered in.
The second area, designated "established turf," consisted of a unifqtm
and dense stand of Kentuclty bluegrass, red fescue, and bentgrass. Little
crabgrass was present in this area in 1960 even though a heavy infestation
(70'f"crabgrass) had occurred in 1959. In order to provide conditions more
favorable for the development of crabgrass within this area, it was subjet
to a rather severe renovation treatment prior to the application of the .
chemicals. Th€l area was clipped at a height of approximately t inch. ,
Several passes were made over the area with a Henderson Thin-Cut set So the
blades cut into the soil approximately t inch. The pre-emergence crabgr8lSs
control materials were then applied and watered in. The experimental des'Jign
was a complete randomized block with eleven treatments in triplicate on .
7 x 7' plots. Seven plots served as checks. The turf was maintained at·..'
approximately 1 inch, well fertilized and adequately irrigated.
The materials were applied on March 29) 1961. All of the chemiCals',
were in granular formuJ.ations and were broadcast by hand without a.iluent.
REO'ULTSANDDISCUSSION
The materials 'Used, rates of application, percentage crabgrass control
and turf injury ratings are found in Table 1.
1 Assistant Professor wld Professor of Ornamental HortiCUlture, respectively,
Cornell Univer~ity, Ithaca, New York.