Effect of site-specific weed management in winter crops on yield and weed populations

Abstract

Site-specific weed management (SSWM) methods allow spatially variable treatment of weed populations according to actual weed abundance, thus offering the opportunity for herbicide savings. However, SSWM's effect on weed population dynamics is not sufficiently understood. In this study, SSWM was conducted based on various application thresholds to analyse the effects on crop yield and weed infestation in the succeeding crop. SSWM was used on a 3.07 ha experimental field in winter wheat (2011) and winter oilseed rape (2012). The whole area was split into application cells of 6 × 10 m and abundance of all weed species 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 post-emergent herbicide application. SSWM resulted in savings of post-emergent herbicides ranging from 71.9% to 100%, depending on the application threshold. Differences in winter rape yield among treatments were generally small and statistically insignificant (P = 0.989). Although some minor changes in weed abundances were observable, the experiment showed that none of the site-specific herbicide treatments caused a significant (α = 0.05) increase of weed species abundance compared to the standard treatment.

Marketable Yield of Potato and Its Quantitative Parameters after Application of Herbicides and Biostimulants

“…Potato is propagated vegetatively, which exposes the crop plant to numerous harmful factors (weeds, pests, viral, fungal and bacterial diseases). As a result of reduced soil tillage and simplified harvest, delayed planting dates, natural manuring and continuous cropping, an increase in weed infestation of fields planted to potato has been observed [6][7][8].…”

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

“…To evaluate the spatial stability of weed populations, Pearson's correlation coefficient was calculated for densities of weed groups between 2011 and 2014. Other details on methods can be found in Hamouz et al (2014).…”

“…In previous work (Hamouz et al 2013(Hamouz et al , 2014, it was shown that SSWM applied to winter cereals and winter oilseed rape had no significant effect on crop yields. The present work evaluates the effect of SSWM on weed populations over a 4-year period based on various threshold values.…”

Development and testing of image processing algorithm to estimate weed infestation level in corn fields

“…Since it is only when infestation surpasses 7.4% that immediate intervention is necessary, this breakdown of a field into areas of low, intermediate and high levels of infestation makes it possible to construct herbicide treatment maps identifying where intervention is needed (Gerhards et al, 2002;Longchamps et al, 2012), with the insertion of such maps in equipment performing localized applications promoting economy in herbicide use (Shiratsuchi et al, 2003). Evaluating a system of images to help in making decisions about intervention in the control of weeds, Hamouz et al (2014) identified a potential reduction of up to 90% in the volume of herbicides needed in comparison with what was recommended by a more conventional method. For Rizzardi and Fleck (2004), densities of 4 or more plants per m -2 of the common weed Bidens pilosa L. can limit the development of soybeans.…”