Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Interference between healthy and rusted groundsel (Senecio-Vulgaris L) within mixed populations of different densities and proportions
AU - Paul, Nigel
AU - AYRES, P G
PY - 1986/10
Y1 - 1986/10
N2 - Plants of groundsel (Senecio vulgaris L.), either inoculated with rust Puccinia lagenophorae Cooke or uninoculated, were grown to capitulum production at a range of densities up to 2240 plants m−2, both in monoculture and together in mixture. Rust infection reduced vegetative growth and capitulum production in monocultures and mixtures. However, in mixture, unequal interference between inoculated and uninoculated plants amplified the effect of rust infection on growth. The relative crowding coefficient of uninoculated over rusted groundsel consistently exceeded unity but showed no clear trend in response to planting density. Rust infection resulted in bimodal frequency distributions of plant height, particularly in mixture, i.e. many rusted plants were stunted and were confined to the lowest layers of the shoot canopy. Thus, the reduced yield of the inoculated component of mixtures resulted from the very severe inhibition of growth of a proportion of rusted plants. However, it appeared that suppressed, rusted plants remained able to respond to limitation of available resources since both dry weight partitioning to the roots and specific leaf area increased. Perhaps because of the ability of groundsel to adapt to unfavourable environmental conditions, rust infection resulted in little mortality. Thus, even heavily rusted suppressed plants were able to produce some capitula and, potentially, seed.
AB - Plants of groundsel (Senecio vulgaris L.), either inoculated with rust Puccinia lagenophorae Cooke or uninoculated, were grown to capitulum production at a range of densities up to 2240 plants m−2, both in monoculture and together in mixture. Rust infection reduced vegetative growth and capitulum production in monocultures and mixtures. However, in mixture, unequal interference between inoculated and uninoculated plants amplified the effect of rust infection on growth. The relative crowding coefficient of uninoculated over rusted groundsel consistently exceeded unity but showed no clear trend in response to planting density. Rust infection resulted in bimodal frequency distributions of plant height, particularly in mixture, i.e. many rusted plants were stunted and were confined to the lowest layers of the shoot canopy. Thus, the reduced yield of the inoculated component of mixtures resulted from the very severe inhibition of growth of a proportion of rusted plants. However, it appeared that suppressed, rusted plants remained able to respond to limitation of available resources since both dry weight partitioning to the roots and specific leaf area increased. Perhaps because of the ability of groundsel to adapt to unfavourable environmental conditions, rust infection resulted in little mortality. Thus, even heavily rusted suppressed plants were able to produce some capitula and, potentially, seed.
KW - Senecio vulgaris (groundsel)
KW - Puccinia lagenophorae
KW - planting density
KW - intra-specific interference
KW - population structure
U2 - 10.1111/j.1469-8137.1986.tb00650.x
DO - 10.1111/j.1469-8137.1986.tb00650.x
M3 - Journal article
VL - 104
SP - 257
EP - 269
JO - New Phytologist
JF - New Phytologist
SN - 0028-646X
IS - 2
ER -