On the Germination of the Weed Seeds in Soil Treated with 2, 4-D (Part 1)

Abstract

1. Digitaria ichaemum MUHL seedling was treated with 0.02 and 0.002% solutions of 2, 4-D, in such manners as follows.
a) Pre-emergence treatment : seeds were put in the Petri's dishes containing 2, 4-D solution, till the coleoptiles emerged.
b) Post-emeigence treatment: seedlings were put in the dishes with the chemicals, after the coleoptiles emerged.
c) All-stage treatment : Seeds were put in the dishes with the chemicals through the entire germinating process.
d) No treatment : seeds were put in the Petri's dishes without 2, 4-D solution, till the primary leaf emerged.
2. In the plots treated with 2, 4-D, many abnormal seedlings appeared. Their coleoptiles and seminal roots dilated abnormally.
3, In the plots treated with 0.02% 2, 4-D solution, mary seeds died after abnormal coleoptiles had emerged. The difference between the pre-emergence treatment with 2, 4-D and the post-emergence one was not seen.
4. In the plots treated with 0.002% 2, 4-D solution, the growth of abnormal coleoptiles and seminal roots was damaged. The pre-em-ergence treatment with 2, 4-D was more effectve than the post-emergence one.