(1) A study, which ultimate object lies to prove how farmers labor for weeding is economized by the use of chemicals, is now in progress by the writers, and in this report tests with CL-IPC (isopropyl N-(3-chlorophenyl) carbama te(II)) are made in barley, rape and onion fields.
(2) 300g. of a 45.8% emulsifiable concentrate of CL-IPC diluted with 108 1. of water was the dose applied to 10 are in a treatment. In each field, three kinds of blocks, i.e. no treatment once and twice treatments, were prepared.
(3) In the barley field treated, crops were influenced for bad and a number of barleys was dead the first treatment, although in the second such a bad effect on crops was not observed. On rape and onion, CL-IPC in the dosage applied was quite safe for use.
(4) A comparison of the total weight of weed per 10 are after treatment was made among the three blocks in each field. Results were as follows.
<tt>
No Once Twice
treatment treatment treatments
Barley field 354.930kg. 10140kg. 1.920kg.
Rape field 470.640 65.295 22.980
Onion field 245.220 11.600 2.940
</tt>
A remarkable effect of weed control with CL-IPC was proved in every treatment.
(5) In the onion field, a comparison among the three blocks was also attempted on the time required for weeding 10 are by hand after chemicl treatment : the times were 41.5, 4.5 and 1.5 hrs. at the blocks of no treatment, once and twice treatments, respectively.