SA Graan Julie 2016

July 2016

fact that such a wide range of fungi were isolated could also point

to infection that occurred after the plant was exposed to a certain

stress. Since the symptoms resembled that of herbicide damage,

the recommendation was made that the producer investigate such

a possibility.

A new project co-funded by the Maize Trust commenced at the

ARC-GCI during April of this year and focuses on the further devel-

opment of the qPCR technology. The succession of the fungal

pathogen complex will be monitored – a first of its kind. This will

evaluate how qPCR technology can improve the understanding of

soilborne diseases and contribute to better management strategies

for producers.

For enquiries contact Dr Aneen Schoeman or

Dr Maryke Craven at 018 299 6100,

BelgroveA@arc

agric.za

CravenM@arc.agric.za .

EXEROHILIUM PEDICELLATUM FUSARIUM EQUISETI

RHIZOCTONIA SOLANI

CONCENTRATION (PG/μL)

Limit of detection

‘Diseased’ plant

5 037

‘Healthy’ plant

29,2

791

45,21

TABLE 1: QPCR RESULTS OBTAINED FOR ROOT ROT SAMPLES BROUGHT IN DURING DECEMBER 2015.

Graph 1: Average fungal frequencies of twelve known root and crown rot pathogens as measured at the Ventersdorp locality over five seasons (2009/2010

to 2013/2014).

1: Root systems of a ‘healthy’ as opposed to a ‘diseased’ plant.

2: The morphological characteristics of the fungal pathogens as observed under a light microscope, A)

Exserohilium pedicellatum

Fusarium equiseti

and C)

Rhizoctonia solani

3: Soybean seedlings resembling symptoms associated with both Pythium root rot and herbicide damage.