COMPARISON OF LEAF-AREA INDEX WITH ROOT WEIGHT FOR ASSESSING PLANT DAMAGE BY SOIL-BORNE PATHOGENS

‘Hymark’ and ‘Mission’ melons (Cucumis melo) were grown in growth chambers over 4 weeks in sand inoculated with the soil-borne pathogens Monosporascus cannonballus, Acremonium cucurbitacearum, or Rhizopycnis vagum. Quantitative information on plant characteristics and biomass was collected from destructively sampled plants.
Leaf-surface area and root mass decreased in plants proportionally with disease severity.
Both the leaf-area index and the root mass were significantly correlated with disease severity index.
However, leaf-area index was 3.5 times more precise and more likely to reflect damage to plant roots than shift in root mass.
Leaf-area index was capable of detecting significant differences in root damage even in cases where root-mass measures failed to do so.
The leaf area index is particularly suitable for non-destructive, continuous evaluation of plant impairment.
Standardized to common scale, quantitative assessment of plant impairment using leaf area index has great potential as a tool for precise and accurate assessment of plant resistance and/or pathogen virulence.
The index may facilitate spatial and temporal comparisons and meta-analyses of data for cucurbits.

VII Eucarpia Meeting on Cucurbit Genetics and Breeding

M. Biernacki, Benny D. Bruton

Acremonium cucurbitacearum, Cucumis melo, image analysis, Monosporascus cannonballus, Rhizopycnis vagum

https://doi.org/10.17660/ActaHortic.2000.510.27