| Abstract: | Abstract Results of an experiment comparing six times of herbicidal application showed that an application of the amine salt of 2,4-D at the rate of 1.0 kg/ha at 50% flowering of the weeds had the most detrimental effect on viable seed production of both winter and rainy season weeds as judged from their germination tests. Delay in the application time of 2,4-D by one week increased seed viability by 150 and 55% in rainy and winter season respectively. Delay of each week in application tended to significantly increase viable seed production. Germination percentage of Triantherna portulacastrum, Digera arvensis, Amaranthus viridis, Amaranthus spinosus, Physalis minima, Phyllanthus niruri, Echinochloa colonum, Acalypha celiata, Flavaria contra-yerba and Cyperus rotundus growing in kharif season when treated at flowering stage was 0,0,0,0,2,0,16,0,14, and 0% respectively as against 44, 66, 76, 58, 82, 66, 90, 26, 92 and 61% respectively for untreated seeds. In the case of winter weeds, germination percentage of Cornopus didymus, Anagallis arvensis, Melilotus indica, Chenopodium album, Chenopodium murale, Convolvulus arvensis, Spergula arvensis, Argemone mexicana, Asphodelus tenuifolius and Sonchus arvensis when treated at flowering stage was 0, 2.7, 0, 5.3, 2.7, 0, 0, 0, 0 and 0% respectively as against 8.0, 30.7, 40.0, 32.0, 33.3, 38.7, 16.3, 18.7, 25.3 and 12.7% respectively for untreated seeds. |
