Vol. 16—1962 - NorthEastern Weed Science Society

'Ihree experiments were conducted in 1961. In1;he first experiment,
the above three outstanding herbicic1es, or combinations of herbicides, were
tested on Calcom peppers and Del. 13-2 tomatoes. Spray applications were "
made with a single-nozzle hand sprayer • Tillam gran\llar applications were
made with a small hand duster. Plot. size was 2 row:e, 20 feet long. Treatments
were replicated three tiDIes in randomized bl~s. Tillam granular
and spray at 4 lb!A, incorporated just before see41ng by discing, raking,
or by irrigation, caused severe injury, particularly of peppers. PCP, 5 lb!A,
and KOCN,16 lb!A, plus TCA, 3 lb!A, applied just before emergence, gave good
weed control with no significant crop injury.
In the second experiment in 1961, the following herbicides were tested
on Calcom peppers and Del. 13-2 tomatoes, using a logarithmic sprayer:
Diphenamid N, N-dimethyl- 0(, ~ -diphenylaoetamide), from 10 to 1.5 lb!A;
Dacthal (dimethyl tetrachloroterephthalic acid), from 12 to 1.8 lb!A;
Stauffer 1870 (ethyl di-n-butyl-thiolcarbamate), from 12 to 1.8 lb!A;
Tillam, from 12 to 1.8 lb!A; Zytron, from 20 to 3 lb!A; and Geigy Prometryne
(2,4-bis(isopropylamino-6-methyl mercapto.s·triazine), from 10 to 1.5 lb!A.
Plot size was a single row 15 feet long. Treatments were replicated
three times in randomized blocks. Rows of peppers were 3t feet apart and
rows of tomatoes were 5 feet apart. Tillam and Sta,uffer-1810 were incorporated
just before seeding, while the remaining herbicides were applied
just after seeding. Diphenamid was the only outstand,1ng herbicide in this
experiment. The minimum rate required for weed contz'ol was 2.6 lb!A, while
the maXimumrate tolerated by peppers was 4.1 lb!A, and the maXimumrate
tolerated by tomatoes was 1.1 lb/A, .
In the third experiment in 1961, Diphenamid, PCP, and KOCNplus TCA
were evaluated on Calcom peppers and Del. 13-2 tomatoes again. Treatments
were applied and replicated as described above for the first experiment.
No crop injury was produced by any of these treatments (Table 1). All
three treatments gave perfect control of broadleaf weeds. Diphenamid gave
perfect control of annual grasses, while PCP, and KOCNplus TCA, gave near
perfect control of annual grasses.
The following two treatments were super-imposed on the PCP, and KOCi'l
plus TeA plots in the third experiment, to extend the duration of weed cori:.
troll Tillam granular, 4 lb!A, raked in, or Diphenamid, 5 lb!A, applied as
an over-all spray. Both chemicals were very effective for extending the
duration of control of both broadleaf weeds and annual grasses. However,
Tillam caused considerable stunting of both peppers,arxl tanatoes. Diphenamid,
on the other hand, had no adverse effect,
Transplantsd Peppers and Tcmatoes
117
Procedure
and Results:
These experiments were located adjacent to the field-seeded experiments.
Therefore, thfl soil and principal weeds were silnilar. Plot size for both