Septoria Blotch of Field Pea
Note Number: AG1164
Published: May 2008
Updated: August 2012
Reviewed: June 2017
Septoria blotch of field peas is usually a minor disease occurring sporadically in Victoria and South Australia but has caused major crop losses in NSW. The disease is often seen on senescing plants late in the growing season. The disease can be prevented by stubble management and crop rotation.
What to look for
Fig1. Typical leaf lesions caused by Septoria.
Fig 2. Fruiting bodies of Septoria on infected pea leaf and tendrils.
The disease is mainly found on the lower, senescing parts of the plant and pods. Diseased areas on leaves are of indefinite size and shape and are yellow then straw coloured to light brown (see Figure 1), often with a lighter centre and a pale yellow halo on the margin. Several such blotches may join together to cover the entire leaf. Within the lesions, pin-point sized black fruiting bodies of the fungus may be seen (see Figure 2). Diseased tissues may dry off prematurely.
Septoria blotch is caused by the fungus Septoria pisi. The fungus survives from one season to the next on infected pea trash and seed. Spores of the fungus are carried by wind from infected trash, into the new crop. Infection is found on the lower foliage where the humidity is high following rain or heavy dews. The disease is favoured by warm temperatures (21 to 27°C) and extended periods of high humidity. Secondary spread occurs during the growing season. Rain splash assists in spreading the disease within a crop. Whilst seed transmission can occur it is unlikely to be important.
Fig 3. Fruiting body of Septoria on an infected pea pod
The disease occurs in most pea growing regions but seldom causes significant yield losses. In susceptible pea varieties, grain yield losses of up to 40 per cent have been reported.
Septoria can be controlled by destroying infected stubble and by crop rotation.
The septoria blotch fungus survives in soil and on old pea trash. It is only safe to re-crop an area with peas after all pea debris has decomposed. Destroying pea stubble by grazing, burning and cultivation will help in reduce the amount of inoculum available to infect new crops. A break of at least two years between successive field pea crops will minimise the risk of disease carry over.
Nearly all field pea varieties are moderately susceptible to septoria, however, the disease appears to be most severe on the short, semi-leafless varieties.
No foliar or seed applied fungicides are registered for use on septoria in field peas in Victoria.
Detailed information on each of the pulse diseases can be obtained from:
- DEDJTR Agricultural Information Notes.
- Pulse Australia
- National Variety Trials
- Grain Legume Handbook.
- Victorian Winter Crop Summary
- Victorian Pulse Disease Guide
- Seed Health Testing in Pulse Crops (AG1250)
- Pulse Seed Treatments and Foliar Fungicides
Contact/Services available from DEPI
Field Crops Pathology, Grains Innovation Park, 110 Natimuk Road, Horsham 3400. Phone: (03) 5362 2111 or the DEDJTR Customer Service Centre 136 186
This Information Note was originally written by Trevor Bretag. It was reviewed by Helen Richardson and Frank Henry, BioSciences Research - Farm Services Victoria, March 2010. This AgNote was last reviewed by Helen Richardson June 2016. Support by the GRDC is gratefully acknowledged.
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Published by the Victorian Government Department of Economic Development, Jobs, Transport and Resources Melbourne 2016
© The State of Victoria Department of Economic Development, Jobs, Transport and Resources Melbourne 2016 This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968. ISSN 1329-8062