Main content area

Effect of weed management on weeds, and on the nodulation, nitrogenase activity, growth and yield of pea (<i>Pisum sativum</i>)

Singh, G., Wright, D.
Acta agronomica Academiae Scientiarum Hungaricae 2006 v.54 no.4 pp. 469-485
Elymus repens, Pisum sativum, Poa annua, Polygonum aviculare, adverse effects, application rate, bentazon, biomass, nitrogen content, nitrogen fixation, nitrogenase, nodulation, photosynthesis, plant growth, seed yield, seeds, sowing, straw, terbuthylazine, terbutryn, weed control, weeds
<p class=MsoNormal align=left style='text-align:left;mso-layout-grid-align: none;text-autospace:none'>Effects of one pre-emergence herbicide (terbutryn/terbuthylazine) and one post-emergence herbicide (bentazone) along with unweeded and hand-weeded controls on weeds and on the nodulation, nitrogenase activity, nitrogen content, growth and yield of pea (<i>Pisum sativum</i>) were studied. Terbutryn/terbuthylazine was applied pre-emergence @ 1.40, 2.80 and 5.60 kg/hawhereas bentazone was sprayed 6 weeks after sowing @ 1.44, 2.88 and 5.76 kg/h. Terbutryn/terbuthylazine controlled all the weeds very effectively, whereas bentazone did not control some weeds such as <i>Polygonum aviculare</i>, <i>Poa annua</i> and <i>Elymus repens</i>. The herbicides decreased the number of nodules, the dry weight of nodules, the nitrogenase activity, the shoot dry weight, the nitrogen content in the straw and seeds, and the seed yield of peas, the effects generally being higher at higher rates of application. The adverse effects of herbicides on these parameters might be due to their effects on plant growth, as both the herbicides are known to adversely affect photosynthesis. Nitrogenase activity did not correlate well with plant-N content or shoot dry weight. However, there was a strong relationship between plant biomass and plant-N content, which suggests that researchers can rely on these parameters for studying the effects of treatments on nitrogen fixation, rather than measuring nitrogenase activity.</p> <p class=MsoNormal> </p>