Emergence dynamics of barnyardgrass and jimsonweed from two depths when switching from conventional to reduced and no-till conditions

Abstract

<p>A cylinder experiment was conducted in northern Greece during 2005 and 2006 to assess emergence dynamics of barnyardgrass (<em>Echinochloa crus-galli</em> (L.) Beauv.) and jimsonweed (<em>Datura stramonium </em>L.) in the case of a switch from conventional to conservation tillage systems (CT). Emergence was surveyed from two burial depths (5 and 10 cm) and with simulation of reduced tillage (<em>i.e.</em> by soil disturbance) and no-till conditions. Barnyardgrass emergence was significantly affected by burial depth, having greater emergence from 5 cm depth (96%) although even 78% of seedlings emerged from 10 cm depth after the two years of study. Emergence of barnyardgrass was stable across years from the different depths and tillage regimes. Jimsonweed<em> </em>seeds showed lower germination than barnyardgrass during the study period, whereas its emergence was significantly affected by soil disturbance having 41% compared to 28% without disturbance. A burial depth x soil disturbance interaction was also determined,<em> </em>which showed higher emergence from 10 cm depth with soil disturbance. Jimsonweed was found to have significantly higher emergence from 10 cm depth with soil disturbance in Year 2. Seasonal emergence timing of barnyardgrass did not vary between the different burial depth and soil disturbance regimes, as it started in April and lasted until end of May in both years. Jimsonweed<em> </em>showed a bimodal pattern, with first emergence starting end of April until mid-May and the second ranging from mid-June to mid-August from 10 cm burial depth and from mid-July to mid-August from 5 cm depth, irrespective of soil disturbance in both cases.</p>

Predicting the Emergence of Echinochloa crus-galli (L.) P. Beauv. in Maize Crop in Croatia with Hydrothermal Model

“…The cessation of emergence with the closing of the leaf canopy has already been documented [5] and explained by the change in soil climate. However, studies based on determination of emergence pattern often are performed in a crop-free field [36][37][38]. Nevertheless, when E. crus-galli emergence was observed without the crop at 12 sites in the United States, the emergence extended into September [39]-much longer than in our study.…”

“…The effect of tillage on the vertical distribution of seed in the seed bank is well known, and different tillage practices can significantly affect field emergence. However, Vasileiadis et al [37] concluded that the emergence of E. crus-galli was stable over the years under different simulated tillage systems (conventional, reduced, and, no-till), so AlertInf could be adopted for maize grown under different tillage conditions considering this fact. Another factor that could influence the emergence and effectiveness of the model is soil type, which was not considered in this experiment and should be further investigated.…”

The effect of three soil tillage treatments on weed infestation in forage maize

“…Nevertheless, its presence was the highest in CT and MT. Some authors [21] also found that emergence of E. crus-galli was stable in treatments with different tillage depths during their research. According to Chauhan and Johnson [22], this weed can become a serious problem in NT.…”