Tolerance of Tomatoes to Pyrenochaeta lycopersici: Comparison of a Tolerant Line with a Susceptible Cultivar in Infested Soils

Abstract

SUMMARY Root rot symptoms and yields of an advanced breeding line of tomato (J513) tolerant to brown root rot (BRR) were compared with those of the susceptible cultivar Ailsa Craig when both were grown in glasshouse soils having different amounts of inoculum of Pyrenochaeta lycopersici Schneider & Gerlach. Less BRR was found on J513 than on Ailsa Craig in both 1972 and 1973 and the decline in yield with increasing soil inoculum was less on J513 than on Ailsa Craig. However, the yield of J513 on freshly sterilised soils was less than that of Ailsa Craig, so that overall the yields of J513 were no heavier than Ailsa Craig on the soils used. Thus, whilst the BRR tolerance was demonstrably effective, further improvements in the agronomic potential of tolerant lines are necessary to exploit this tolerance where BRR is not severe.

Effect of soil amendments and biological control agents (BCAs) on soil-borne root diseases caused by Pyrenochaeta lycopersici and Verticillium albo-atrum in organic greenhouse tomato production systems

“…The severity of corky root rot symptoms was not scored in experiments presented here. Instead, RFW was used as an indication of the level of root loss due to soil-borne diseases, since corky root rot severity is closely correlated with root loss (Last and Ebben 1966;Ebben 1974;Ebben et al 1978;Pohronezny and Volin 1991). The difference in RFW between plants grown in steam-disinfected and non-steam-disinfected soils was used as a measure of overall root damage/ loss caused by the different soil-borne pathogen inocula.…”

“…(especially V. dahliae and V. albo-atrum). Corky root rot is more severe in regions with cooler climates such as countries in northern Europe, with yield losses of up to 75% reported (Ebben et al 1978;Campbell et al 1982). However, it can also cause problems in southern European countries especially in glasshouse crops during the winter months and in early open-field tomato crops (Pegg and Brady 2002).…”

“…However, it can also cause problems in southern European countries especially in glasshouse crops during the winter months and in early open-field tomato crops (Pegg and Brady 2002). The pathogen, which also attacks a wide range of other glasshouse crops including pepper, aubergine, cucumber, squash, and melon, is very persistent in soil and therefore cannot be controlled by breakcrops or rotation of crops in the greenhouse (Ebben et al 1978;Grove and Campbell 1987). Verticillium spp.…”

The relationship between brown and corky root rot caused by Pyrenochaeta lycopersici and yield loss in tomatoes established by the use of artificially infested soils

“…Upstone (1968) found that in one experiment, differences in severity of brown root rot were not reflected in yield, and Jeves & Smith (1980) found no signifieant yield effects resulting from disease differences following a number of fungicide treattnents. Ebben et at. (1978) have pointed out that, under poor environmental conditions, factors other than brown root rot may limit yield, and an affected root system, although decreased by the disease, tnay still be able to support a poorly growing plant.…”