Composition of the stubble weed flora and its role for Heterodera schachtii in the year preceding sugar beet production

Abstract

Summary In Germany, sugar beet is often rotated with 2 years of cereal. Extensive fallow periods between cereal harvest and autumn primary tillage allow for a weed flora to develop. Broad‐leaved weeds could potentially be alternate hosts for the common nematode Heterodera schachtii, one of the most important pests of sugar beet. Between 2009 and 2012, annual weeds developing in cereal stubble fields during July to mid‐October in the season prior to sugar beet were surveyed, including known hosts of H. schachtii. Yearly weather patterns and agronomic practices possibly impacted weed species composition and weed population densities. During September, Chenopodium album, Cirsium arvense, Convolvulus arvensis, Mercurialis annua, Polygonum spp., Solanum nigrum and Sonchus spp. occurred at the highest frequencies. Weed hosts of H. schachtii were present, but densities, frequencies and uniformity were limited. In 2010 and 2011, staining for nematodes in roots revealed juvenile penetration of some weeds but few adult stages. No indication of nematode reproduction of H. schachtii was found on these weed hosts. A fairly stable weed flora was detected on stubble fields that could provide some carry over for weed species. An elevated risk for nematode population density build‐up on these weeds was not found and management of these weeds at the observed densities during the stubble period for nematological reasons appeared unnecessary.

Linking species traits to agroecosystem services: a functional analysis of weed communities

“…Lifespan × regeneration form has only one missing value, while full information is available for the remaining five traits. Weeds are known to host pests, pathogens, viruses and nematodes (disservice; Meinecke et al ., ) but also natural enemies (service; Norris & Kogan, ); this is a relevant issue, but the available information is so scant and interactions among taxa are so complex and crop and context specific that including these data in a one‐table database was not feasible.…”

Quantitative reproductive potential of Heterodera schachtii on weeds typical for late summer fallow in sugar beet rotations

“…Weeds for these tests were chosen based on their abundance in stubble fields during summer fallow (July until October) preceding sugar beet cropping (Meinecke et al ., ) and others because of their known host status (Gleissl, , ). In a first step, the full set of selected weeds (39 species total) and five standards, including one cultivar resistant and one susceptible of Raphanus sativus L. var.…”

“…In a 4‐year survey of commercial fields of Franconia in southern Germany, Chenopodium album L., Cirsium arvense (L.) Scop., Convolvulus arvensis L., Mercurialis annua L., Polygonum spp., Sonchus spp. and Solanum nigrum L. each occurred on >25% of the fields (Meinecke et al ., ). Some of these weeds are known hosts of Heterodera schachtii that is one of the most important nematode pests of sugar beet (Müller, ).…”

Evaluating resistant brassica trap crops to manage Heterodera schachtii (Schmidt) infestations in eastern England

“…Fat hen ( Chenopodium album ), a known host of BCN, is commonly found across the host farm . However, fat hen is classed as a relatively poor host of BCN and Meinecke et al . concluded that common arable weeds do not require control for nematological reasons.…”

“…Weed growth was observed and is reflected in the NDVI measurements on the fallow plots. Fat hen ( Chenopodium album ), a known host of BCN, is commonly found across the host farm . However, fat hen is classed as a relatively poor host of BCN and Meinecke et al .…”