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Finding management solutions
to a devastating pathogen
S
clerotinia sclerotiorum
is the causal agent of Sclerotinia
stem rot on soybean and Sclerotinia head rot on sunflower.
The fungus can infect more than 400 host species and
can survive in the soil for up to eight years (depending on
environmental conditions) – thus making this disease a challenge to
manage.
No resistant soybean or sunflower cultivars are available and only
a few chemical control products are registered for use against
Sclerotinia.
In the light of the above challenges and after attending the National
Sclerotinia Initiative in Minnesota in January last year, we created
a platform for young researchers to assist one another and share
their experiences with Sclerotinia research in South Africa. How-
ever, there was significant interest from beyond academic
institutions, and so the South African Sclerotinia Research Network
(SASRN) was born.
SASRN is a virtual community of practice for Sclerotinia researchers
in South Africa and serves as a platform where collaborations can
be established, and parallel and comprehensive research goals can
be met that benefit multiple investigators and the public. We aim to
generate social and academic capital where experienced investiga
tors can exchange knowledge gained with peer investigators.
In September last year, SASRN had its inaugural meeting and
has since then continued working with Grain SA as well as industry
and academic partners. Currently, SASRN is applying for research
funding to investigate solutions for Sclerotinia diseases of soybean
and sunflowers and, in future, canola.
Prediction model
Researchers at the University of the Free State are developing
a prediction model to assist producers in identifying the risk of
Sclerotinia disease developing at critical growth stages during the
cropping season.
Disease forecast models serve as an early warning system to assist
producers in optimising the timing of fungicide applications to
ensure optimal efficiency. In Europe, canola field experiments
between 1981 and 2004 indicated that fungicide sprays were
only 27% to 33% cost-effective against Sclerotinia stem rot
(Koch
et al
., 2007).
In Sou h Africa, chemical agents represent a significant portion
of a producer’s production costs, and forecast models can assist
producers in either minimising fungicide applications or increasing
the efficacy of the application without compromising the degree of
control.
Thus the objective is to accurately predict when the host, environ
ment and pathogen interact in such a manner that disease can occur
and can cause economic loss. The effects of other driving variables
such as resistance, planting dates and cropping practices are also
considered.
There are three key issues which SASRN would like to focus on:
Generate a local centre of excellence and expertise.
Be the ‘face’ for Sclerotinia researchers nationally and inform
the international community of the role South Africa can play in
Sclerotinia research.
Finding practical solutions for South African producers against
diseases caused by
Sclerotinia
spp.
While producer-focused research to develop practical management
strategies to
Sclerotinia
diseases is the main focus of the network,
the collaborations established by the network is also a crucial
aspect. The collaborations promote communication between parties
involved, preventing duplication and allowing researchers to inform
industry directly of findings, and
vice versa
.
This network is also a platform where industry and academia can
listen to the needs of producers with a view of actively resolving
issues through applied and directed research questions. The
community of practice established will drive the communication
between producers and network members.
If you are a researcher or producer and you are interested in
connecting with us and growing our network, please contact Lisa
at
coetzeela@ufs.ac.za
. Please support our
page, South
African Sclerotinia Research Network, tag us
@sclerotiniaza
, use the
#sclerotiniaZA
or contact
sclerotinianetwork@gmail.com
if you are
interested in more information.
65
September 2018
FoCus
Integrated pest control
The South African Sclerotinia Research Network:
Lisa Rothmann,
Plant Sciences Department, University of the Free State and
Miekie Human,
research assistant, Grain SA
1: Apothecia – fruiting structure, responsible for the
production and release of ascospores of
S. sclerotiorum.
2: Mycelium of S. sclerotiorum on soybean stem
(Sclerotinia stem rot).
3: Severe sunflower head rot caused by
S. sclerotiorum
.
1
2
3