Vol. 15—1961 - NorthEastern Weed Science Society

A duplicate test was started August 11. This location with a similar sandy
loam soU had very good uniformity. The weather I however, was mucb different.
Irrigation was supplied after the first treatment. Light showery weather
prevailed tor tbe next week. l-bisture at the surface was almost continuously
good for seed germination. However, no substa'Zltial rainfall occurred.. By
the time of the six-d.ey-treatment all crops seedings had emerged. In Table 4
are presented. the crop and weed control ratings taken three weeks following
the first treatment. The data show a striking picture of increased injury at
the time of crop sprouting and less deme&eat the siXth day when the crap had
Just emerged. The same general trend but much less Pronounced was evident
in weed control. These results strongly suggest that aQ'tivity of CDECin
relation to crops frequently considered. "tolerant" is definitely influenced by
time of application. Furthermore, that actiVity on weeds species is perhaps
increased when the seeds are sprouting.
Tabie 4. The influence of time of CDICapplication in relation to date of
crop seeding •
4 lbs. of CDEC . CroPS*
Beets Spinach· Broccoli* . Weeds!!
0 days 8.00 8.25 7.' 6.0
2 " 7.75 6.25 7.5 7.0
4 " 3.50 3.75 4.5 7.5
n
6 6.75 5.50 6.5 6.0
Check 8.0 7.00 7.5 2.2
'!I Check plots contained high populations of purslane, cregrass and galinsoga.
* Ratings of crops are en average of four values for each observatlon
except tor broccoli, which is for two values. 9. perfect growth; 7 ==
slight stunting but commercial.ly acceptable; 3 .. severe stunting and reduce~.
stand; 1, ==complete kUla
Weed control ratings: 9 .. l~ control; 5. subatantial weeding needed
for commercial control; 1 • complete heavy ground cover.
DiacU8sion
In the tests reported here. there were several observations that need
critical evaluation and interpretation. Results nth formulation were somewhat
variable but were definitely not an important factor influencing overall
CDECperformance •
. Mechanical incorpOration was inferior to irrigation as a meansof enhaD.cing
CDECactivity 'Whenthe soil was fairly dry. However, under condit
ions as in test twO, where underneath the surface, seed germit!ation occurred
without additional water, mechanicsl was generally ae good as watering. An
important exception was tt1esuperior results obtatned with theb1gber rate of
water u.ed1a;telyafter applying CIBC. No detin1teatatelDent can be made on
the reasons tor thea41 result,. One possibil1ty 1. that mechanical incorpora.­
tion resulted in a ~t...~ penet.nt,.1on o.r-tbt herb1c1de than d1d