TY - JOUR

T1 - A new approach to quantify weed suppression, crop tolerance and weed-free yield in cereal variety trials without weed-free plots

AU - Rasmussen, Jesper

AU - Jensen, Signe M.

AU - Mariegaard Pedersen, Tove

N1 - Funding Information: The experiments were conducted as a part of the FREJ project (J.nr. 667‐00251) funded by The Danish Agricultural Agency (GUDP), Ministry of Environment and Food of Denmark. The publication was produced with financial support from the Nordic Public Private Partnership for pre‐breeding in cultivated plants (NordGen) (Project nr. PPP_1804). No conflict of interests has been declared. We thank three anonymous reviewers whose comments/suggestions helped improve and clarify this manuscript. Publisher Copyright: © 2021 European Weed Research Society

PY - 2021

Y1 - 2021

N2 - Cereal varieties are commonly tested in the presence of weeds in organic agriculture, and a variety of test programmes with weeds are relevant in relation to fields containing herbicide-resistant weeds. However, the interpretation of results from variety trials with weeds is complex because different levels of weed pressure affect the yield differently. Crop yield is a result of the combined effect of weed suppression, crop tolerance and the weed-free yield. Until now, there has been no attempt to separate weed suppression, crop tolerance and weed-free yield in ordinary variety trials without weed-free plots. This study applied a new approach based on the combination of functional trait analysis and analysis of variance (ANOVA). A total of 16 variety trials were analysed with early crop coverage, final canopy height and disease severity as functional traits. The main objectives were to quantify weed suppression, crop tolerance and weed-free yield in spring barley varieties, and to evaluate the importance of the trade-off between weed suppression and weed-free yield. Results showed that early crop coverage and final canopy height both increased weed suppression, and taller cultivars tolerated weeds better than shorter cultivars. However, a trade-off between canopy height and weed-free yield made it difficult to justify the selection of tall varieties unless the weed pressure was at its maximum level in the trials. Large early crop coverage was an advantage in terms of weed suppression and weed-free yield, making early coverage a better selection criterion than final canopy height under the condition that early coverage is a result of genotypic variation. Future studies have to show how well genotypic and phenotypic variations are related in terms of early coverage and final canopy height.

AB - Cereal varieties are commonly tested in the presence of weeds in organic agriculture, and a variety of test programmes with weeds are relevant in relation to fields containing herbicide-resistant weeds. However, the interpretation of results from variety trials with weeds is complex because different levels of weed pressure affect the yield differently. Crop yield is a result of the combined effect of weed suppression, crop tolerance and the weed-free yield. Until now, there has been no attempt to separate weed suppression, crop tolerance and weed-free yield in ordinary variety trials without weed-free plots. This study applied a new approach based on the combination of functional trait analysis and analysis of variance (ANOVA). A total of 16 variety trials were analysed with early crop coverage, final canopy height and disease severity as functional traits. The main objectives were to quantify weed suppression, crop tolerance and weed-free yield in spring barley varieties, and to evaluate the importance of the trade-off between weed suppression and weed-free yield. Results showed that early crop coverage and final canopy height both increased weed suppression, and taller cultivars tolerated weeds better than shorter cultivars. However, a trade-off between canopy height and weed-free yield made it difficult to justify the selection of tall varieties unless the weed pressure was at its maximum level in the trials. Large early crop coverage was an advantage in terms of weed suppression and weed-free yield, making early coverage a better selection criterion than final canopy height under the condition that early coverage is a result of genotypic variation. Future studies have to show how well genotypic and phenotypic variations are related in terms of early coverage and final canopy height.

KW - competition

KW - crops

KW - cultural weed control

KW - integrated weed management

KW - methodology

KW - non-chemical weed management

KW - organic agriculture

U2 - 10.1111/wre.12499

DO - 10.1111/wre.12499

M3 - Journal article

AN - SCOPUS:85112076482

VL - 61

SP - 406

EP - 419

JO - Weed Research

JF - Weed Research

SN - 0043-1737

IS - 5

ER -