Vol. 16—1962 - NorthEastern Weed Science Society

Asparagus
The results of weed control tests in asparagus are presented in
Table II. Crabgrass was perhaps the most persistent weed present in
th*i\plots.
Zytron was included in the tests because this chemical is considered
to be very specific for controlling cra~sra~s. vThere Zytron
was used, weed control was satisfactory for several weeks but long
before the end of the cutting season these plots were badly infested
with pigweed, lamb's quarters and crabgrass. Atrazine, and more
particularly Simazine, was vel;'y effective in coatrolling weeds in
these tests. This was also true in the 1960 tests (3). No significant
differences were displayed among means of the plots as far as
total or marketable yield of asparagus spears was concerned.
Last year we reported that where monuron had been applied yearly
for four years an oat bioassay test indicated that none of the chemical
persisted in the soil over winter (3). A cucumber bioassay in the
spring of 1961 corroborated the earlier finding, and also indicated no
toxic residues from 2.5 to 5.0 lb. applications of Atrazine and Simazine
made one year prior to the test.
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Tomatoes
Certain chemicals that have some herbicidal properties have been
reported as being selective for tomatoes. Results from testing some
of these are presented in Table III.
Tillam was incorporated into the soil with a rototil1er just prior
to plantin3; Amiben was applied as granules and Casoron, Sola~Diphen~id
and Dacthol were applied as sprays at lay-by. Only one application was
made of the chemicals. Although Solan appears to be the most promising
of the materials that have been tested, in 1960 when two applications
were made, considerable folia3e injury resulted to the crop. Broadleafed
weeds were controlled well in those tests but crabgrass grew
rampant. The one application in 1961 reduced growth of broadleafed
weeds without perceptible foliage injury. Weed control was not good,
however, and crabgrass was abundant and vigorous. Yields were not
affected in the 1961 tests here but in 1960 Moran (4) reported highly
significant reductions in yield and fruit size in tests conducted on
two different soil types. .
Seedling tomato plants three to four inche.,talU were killed with
a Solan spray at the rate of four pounds per acre i$1 50 gallons of water.