Effects of tillage and reduced herbicide doses on weed biomass production in winter and spring cereals

Abstract

The effects of different tillage systems and dose reduction on the efficacy of triasulfuron & chlortoluron mixture in the post-emergence control of annual broad-leaved weeds in winter wheat and spring barley were studied on lessive pseudogley soil in north-eastern Croatia during 1997-2000. Total dry biomass production in untreated plots was significantly influenced by tillage and it was lowest in continuous mouldboard ploughing (99 kg/ha), medium and similar in mouldboard ploughing/disk harrowing alternating every second year and in chisel ploughing (218 kg/ha) whereas the biomass was highest in continuous disk harrowing (422 kg/ha). Thereby the proportion of annual broad-leaved weed biomass was 70, 63, and 28%, respectively. Chenopodium album L., Ambrosia artemisiifolia L., Ch. polyspermum L. and Polygonum aviculare L. are the most abundant annual weed species in all tillage treatments. One half and one quarter of the recommended rate decreased the control efficacy of total weed biomass by 12 and 19%, respectively in wheat and by 6 and 15%, respectively in barley compared to the highest dose but they still provided a very good biomass control of main annual weeds (94-96 percentage units). The efficacy of reduced herbicide doses in the control of annual broad-leaved weeds did not vary significantly between tillage treatments and growing seasons. Significant interaction with continuous disk harrowing tillage and one-quarter herbicide dose was detected in the last year of wheat trial when perennial weeds increased their biomass proportion 8 times compared to four years before.

Influence of soil tillage and weed suppression on winter wheat yield

“…The RT treatment did not express similar peaks, and compaction was significantly lower than CT at given depths (10-21 and 28-39 cm). In the first season (2008/09), there was a significantly higher mass of the weed at RT in comparison with CT (Table 1), whereas there were no significant differences among herbicide treatments, although results suggest that all herbicide treatments reduced weed biomass in comparison with the herbicide control (NH), which confirms finding of Knežević et al (2003) that half herbicide dosages can suppress weed as effectively as recommended dosages. Higher weed pressure on RT, however, significantly reduced winter wheat yield in comparison with CT ( Table 2), most likely due to the competition for water in a dry spring season of 2009.…”

Herbicide Doses and Application Times in Weed Suppression on Different Red Bean Varieties

“…Increasing the dose of herbicide application from 1.5 to 3.5 li/ha enhanced the percent of weed biomass control; weeds biomass control was nearly 100% in 3.5 li/ha. Knezevic et al (2003) reported that although the full dose of herbicide caused the highest weed control, 25% of the full dose also resulted in an acceptable weed control [18]. Red bean yield and yield components.…”

Biochar and Fertilization Effects on Weed Incidence in Winter Wheat

“…At the investigated locations, a typical common weed flora for the wheat community of Eastern Croatia was determined [43,44]. According to the life cycle and the leaf shape, most weed species belonged to annual broadleaf species.…”