Weed species composition of maize fields in Germany is influenced by site and crop sequence

Abstract

Summary During the last decade, maize has become the crop with the second largest acreage in Germany. Therefore, agricultural advisors and the plant protection sector are interested in an overview of the weed species composition in maize fields, their determining factors and trends. From 2001 to 2009, a weed survey was conducted in 1460 maize fields throughout Germany. Data on crop management and soil characteristics were collected via farmer questionnaires. Principal component analysis and redundancy analysis were used to analyse patterns in weed species composition. The late spring and summer germinating species Chenopodium spp., Echinochloa crus‐galli and Solanum nigrum occurred with high densities and frequencies, but their occurrence was determined by different factors. Other frequent weed species were those that typically accompany autumn‐sown crops. The variation in species composition was significantly related to environmental factors (9.1% explained variance), particularly geographical latitude and precipitation, and management factors (4.7% explained variance), particularly crop sequence. The relative importance of these factors seems universal, when compared with surveys in other crops and regions. The factor ‘year’ was of minor importance (0.9% explained variance). Over the 9‐year period, no changes in weed species composition could be determined. The results suggest that despite the limited impact of crop management on weed species composition, farmers can use crop sequence to suppress individual species. The survey furthermore sets a baseline against which future changes can be measured in a landscape of rapidly changing agricultural land use.

When herbicides don't really matter: Weed species composition of oil pumpkin (Cucurbita pepo L.) fields in Hungary

“…3). This is in accordance with the findings of other Hungarian (Pinke et al, 2016(Pinke et al, , 2013(Pinke et al, , 2012 and similar European studies (de Mol et al, 2015;Lososov a et al, 2004), where climatic and edaphic factors were more important than land use. Anyway, it should be noted that large gradients can positively influence the importance of environmental factors.…”

“…Preceding crop was found to be the most important explanatory predictor among cultural variables, which concurs with the earlier findings in Hungarian poppy and sunflower (Pinke et al, 2013(Pinke et al, , 2011, in German oilseed rape and maize (de Mol et al, 2015;Hanzlik and Gerowitt, 2011), as well as in French arable fields (Fried et al, 2008). According to the present study, the most characteristic species associated with the preceding crop maize was Abutilon theophrasti Medik., while A. artemisiifolia tended to be most typical after the previously cropped cereals, and Amaranthus powellii S. Watson followed generally oil pumpkin in greater abundances (Fig.…”

Methods to conduct and analyse weed surveys in arable farming: a review

“…Two surveys or parts of repeated surveys included in this overview provide examples for such public-private partnerships. While private partners are mainly interested in general species overviews and the results of first steps in data analyses, not necessarily published internationally (Mehrtens et al 2005;Goerke et al 2008), public partners can create extra value through more innovative data analyses (Hanzlik and Gerowitt 2011;De Mol et al 2015).…”

Ökológiai és agrotechnikai tényezők hatása a szántóföldi gyomtársulások faj- és jellegösszetételére = Effects of environmental and management factors on species and trait composition in arable weed communities

“…A Mercurialis annua a melegebb régiókkal és a tavaszi vetésű előve-teményekkel, míg a Solanum nigrum a több csapadékkal társult (Hanzlik és Gerowitt 2011). Németországi kukoricavetésekben a fajkompozícióban talál-ható variancia szignifi káns mértékben kapcsolódott a földrajzi szélességhez és a csapadékhoz, valamint a vetésforgóhoz (de Mol et al 2015). Az Echinochloa crus-galli például főként Észak-Németország csapadékban gazdag vidékein fordult elő, ahol a kukorica gyakori összetevője a vetésforgónak.…”