Vol. 15—1961 - NorthEastern Weed Science Society

108.
Table 1. Results from re-p1anting plots which had given excellent initial
weed kill and severe initial crop damage.
dhemical Lbs. Replanted Crop Ref!Pons41
Broccoli Cabbage Lettuee Spinach
1. Dacthal 6 se1. se1. 8.5 8.0
2.
1\
8 se1. se1. ' 8.5 8.0
3. Hercules 7175 2 1.0 1.0 1.0 6.0
1\
4. n
3 1.0 1.0 1.0 4.0
5. " 7442 4 7.5 7.5 8.0 7.0
It
6.
n 6 4.5 4.5 7.0 8.0
1\
7. 8043 2 9.0 9.0 8.0 7.0
II
II
8. 3 9.0 9.0 8.5 8.0
9. Niagara 5996 1 1.0 1.0
10. n n 2 1.0 1.0
11. Amiben 4 gran. 9.0 9.0
,11Soil raked and crops replanted 33 days after initial treatment and.
planting.
Se1... selective on these crops initially
9- perfect growth; 7 • acceptable; 5 - stunting; 1 :l:Il kill.
Data on crop responses are presented in Table 2. It .can be seen that with
the two Stauffer materials delayed planting had a marked influence on crop
response. Pract,ica11y all toxicity from the two pound. rates of EFTCand 2061
was eliminated atter two weeks. The higher rates still showed some toxicity.
Soil moisture during the trEatment and planting period averaged higher than
normal because rainfall was substantial following a heavy early irrigation.
This might have increased the rapidity of breakdown or degree of leaching.
However, the Niagara and Hercules compounds retained much of their initial
high levels of tonci ty even after two weeks.
A third test was conducted on the same sandy loam soil. Only two eompounds
were included, EPTCand St. 2061. ' Two rates of each were worked into the soil
either by raking' or by'disking. Six plantings of beets and 'spinach were made
at approximately three day intervals .following treating. 'Ratings of crop responses
were made approJdmate1y Beven weeks following treating. Results from
this test were difficult to interpr.etbecause gali.nsoga was present in vatying
amounts throughout the experimental area. Neither EFTCnor St. 2061 gave
control, thus later crop plantings were at a serious competitive disadvantage.
This resulted in stunted plants. ' However, .based on initial stands, it appMTi;).O
that the previously mentioned general trend of reduced toxicity with EFTCand
2061 after ten to fourteen days also held in this test.
'­