Vol. 15—1961 - NorthEastern Weed Science Society

73.
COHBIltit.TloNS' OF cnu:'PITH CDAA· AND'
{"HERCOMPOmmS FOn\JEEDING VEGETABLES
Joseph Cialone and R. D. Sweet
Department of Vegetable Crops, Cornell University, Ithaca, l~. " ,
GrOWerst:requently use several ~n8ecticides or~cides in combination
in order to control·the range of pests that may attack a given veretable.
However, the use of herbicides in combination is negligible, except in a few
isolated cases such as CIPC plus·CDAA for weed control in onions on muck
soils. The great majority of other herbicide treatments involwone chemical
applied once to. a gi.V'encrop. .
Since ve(!etables almost always have two or more weed species prevalent
in a given field, and since the areas of production are scattered over many
soils and climates, a tremendous number of weed species are potential pests
for any given vegetable planting. It is highly unrealistic to expect one
herbicide to be effective under all these environmental conditions and against
all possible weed species.
her­
The purpose of the studies reported here was to make a small start
toward the much needed and extremely complicated problem of evaluating
bicide combinations.
Experimental.
Since these tests were considered to be only a partial attack on a large
problem,. the number of chemicals was arbitrarily limited. Two general types
of tests were included 1) logarithmic caubinations of two chemicals and
2) specific rates ofchem1.cals on a given series of plots •. All tests were
located on a Dunkirk sandy loam.
Losarif,hmic Test
s "
The logarithmic type applications were made with a conventional logarithmic
sprayer mounted on a Jeep .YThe applications of the two chemicals invol
ved were made simultaneously by having one chemical in the concentrate
tank and the other in the diluent tank. In another plot the position of the
two chemicals j.n the sprayer was reversed. Each plot was 50 feet long. The
sprayer was operated so that the half dosage distance was 20 feet.
On July 29 the experimental area was fitted to a very fine seed bed and
di vided into plots 6 x SO. In the central portion of the plot six rows of
vegetables were seeded immediately lengthwise of each plot. Rows were
spaced six inches apart. This left adequate area for the Jeep to travel over
the plots without daniave to the seeded area. Each treatment was replicated
twice.
~a,pcr No. 4S3of the Department of Vegetable Crops, Cornell University.
11 Loaned by Dr. S. 1'1. Fertig of the Cornell University Agronomy Department.