Impact of site-specific weed management in winter crops on weed populations

Abstract

This work is focused on evaluating the effects of site-specific weed management (SSWM) on weed populations over a 4-year period. SSWM was used on a 3.07 ha experimental field during 2011-2014 in a rotation of winter wheat and winter oilseed rape. The area was split into application cells of 6 × 10 m and weed abundance was evaluated manually in each cell. Four different herbicide treatments were tested. Standard whole-field herbicide application (blanket spraying) was treatment 1. Treatments 2, 3 and 4 comprised SSWM using different thresholds for postemergent herbicide applications. SSWM resulted in herbicide savings of 6.3-100% for Galium aparine, 0-84.4% for other dicotyledonous weeds, and 31.3-90.6% for annual monocotyledonous weeds. SSWM led to significantly increased density of G. aparine and Tripleurospermum inodorum in the final experimental year when compared to the blanket treatment. Negative correlation coefficients between 2011 and 2014 plant densities found in SSWM treatments (−0.237 to −0.401) indicate that Apera spica-venti does not establish a long-term soil seed bank.

Economic potential of site-specific pesticide application scenarios with direct injection and automatic application assistant in northern Germany

“…Only at the field plot 'Sickte 15' in 2019, the yield was 1.4 t (16%) above the conventional application field plot. In other studies, yield increases by precision agriculture technologies in weed management could also not be clearly observed either in field trials or in model estimations (Gerhards et al, 2011;Hamouz et al, 2013Hamouz et al, , 2014. Hamouz et al (2013) found that site-specific weed management applied to winter cereals and winter oilseed rape had no significant effect on crop yields.…”

“…Hamouz et al (2013) found that site-specific weed management applied to winter cereals and winter oilseed rape had no significant effect on crop yields. On the other hand, Hamouz et al (2014) found negative correlation coefficients between plant densities in site-specific weed management treatments indicating that some weeds e.g. Apera spica-venti did not establish a long-term soil seed bank.…”

“…However, when a conventional plot experiment was set up in the same field of the site-specific treatments, no statistically significant grain yield difference between the treatments was found (Gerhards et al, 2011). Hamouz et al (2014) state that even if weed control is intensive, an increase in some weed populations may occur in a field due to repeated cultivation of the same crop. However, it should be considered, that weed population dynamics are affected not only by herbicide application but by many other factors, such as crop rotation and soil conditions (Hamouz et al, 2014).…”

“…Hamouz et al (2014) state that even if weed control is intensive, an increase in some weed populations may occur in a field due to repeated cultivation of the same crop. However, it should be considered, that weed population dynamics are affected not only by herbicide application but by many other factors, such as crop rotation and soil conditions (Hamouz et al, 2014). Thus, it seems to be difficult to attribute yield effects clearly to site-specific herbicide treatments.…”

“…Thus, it seems to be difficult to attribute yield effects clearly to site-specific herbicide treatments. Finally, Hamouz et al (2014) emphasised that crop rotation should be considered as an integral part of each weed control system due to seed persistence in the soil. Additional studies on yield effects of strategies with reduced pesticide use could be helpful, since potential yield increases represent additional economic benefits for farmers to apply precision agriculture technology (Christensen et al, 2009).…”