55
September 2014
PRODUCT*
ACTIVE INGREDIENT(S)
RATEPERHA
Abacus
Epoxiconazole+Pyraclorostrobin
1 000ml
Acanto 250SC
Picoxystrobin
300ml
Cabrio
Pyraclostrobin
250ml
Capitan 250EW
Flusilazole
400ml
Folicur 250EW
Tebuconazole
750ml
Flint 50WG
Trifloxystrobin
100g
Soprano 125SC
Epoxiconazole
800ml
Acanto 250SC+Capitan 250EW
Picoxystrobin+ Flusilazole
300ml + 400ml
Cabrio/Folicur
Pyraclostrobin/Tebuconazole
250ml/750ml
Flint/Soprano
Trifloxystrobin/Epoxiconazole
100g/800ml
Prosper Trio/Prosaro 250EC
Tebuconazole+Triadimenol +Spiroxamine/Tebuconazole
+Prothioconazole
500ml/400ml
Control (no fungicide applied)
-
-
TABLE 1: LISTOF FUNGICIDES EVALUATEDONWHEATATMALMESBURYAND TYGERHOEKDURING 2013/2014.
*Eachproductwas applied twice, i.e. at seven leaf and flag leaf stages;whereproducts are separatedby ‘/’, twodifferent productswere applied, one at seven leaf and the
other at flowering stages. E.g. Cabrio/Folicur: Cabriowas applied at seven leaf stage followedby Folicur at flag leaf stage.
Graph 1: Yieldof SST 88 andSST 056 in response todifferent fungicide applications atMalmesbury.
Graph 2: Yieldof SST 88 andSST 056 in response todifferent fungicide applications at Tygerhoek.
A significantly higher yield for SST 056
was obtained from Acanto, Abacus and a
mixture of Acanto and Capitan applied at
seven leaf and flag leaf stages (Graph 1).
At Tygerhoek, Abacus, Cabrio, Folicur (each
applied twice, i.e. at seven leaf and flag
leaf stages), and Cabrio applied at seven
leaf followed by Folicur at flag leaf stage,
resulted in significantly higher yields of
SST 88 and SST 056 compared to controls
(
Graph 2
). At this locality, Cabrio and
Abacus increased the yield of SST 88 and
SST 056 by 0,850 ton/ha and 0,502 ton/ha,
respectively (Graph 2.)
At both localities, yield response to
fungicide application was greater for the
rust susceptible cultivar SST 88 than for
SST 056. The increased yield of SST 88
following fungicide application may have
been partly due to the effect of the latter in
reducing the level of foliar diseases.
On theotherhand,althoughdiseaseseverity
on SST 056 was insignificant, fungicides
significantly increased its yield over the
untreated control at the two localities.
This suggests that certain fungicides
could increase grain yield not only by
controlling diseases, but also through other
mechanisms, probablydue to their effect on
thephysiologyof thewheat plant. However,
the yield increment achievedwith fungicide
applicationon the resistant cultivar SST056
appeared tobe relatively low.
Some of the fungicides evaluated here,
includingAcanto, Cabrio and Flint, have not
been registered for use on wheat in South
Africa. However, they are registered for the
control of various diseases on other crops.
Acanto is registered for the control of some
barley diseases, whereas Cabrio and Flint
are registered for usemainlyon fruit crops.
In thisstudy,Cabrioapplied individuallyor in
combination with Folicur, performed better
thanmostof the remaining fungicides.Thus,
Cabrio appears to be a potentially useful
product for the control of wheat diseases.
However, additional tests are required to
confirm these resultsbefore recommending
Cabrio for useonwheat inSouthAfrica.
Conclusion
Fungicides can significantly increase wheat
yields by effectively reducing disease
development. They can provide profitable
control on susceptible cultivars grown
under favourableweather conditionswhere
diseasepressure is likely tobehigh.
Among fungicides registered for use on
wheat in South Africa, and tested in this
study, Abacus and Folicur appear to be
promising in terms of controlling leaf and
stem rust with positive yield responses.
Of those fungicides not registered for use
on wheat, Cabrio appears to be the best
performer. However, this result needs to
be verified with additional tests before this
fungicide can be recommended for the
control of wheat diseases. The resistant
cultivar included in this trialshowedasmaller
yield response to fungicide application,
suggesting that it may not be necessary to
apply fungicides when resistant cultivars
areplanted.
For more information, con-
tact Dr Tarekegn Terefe at
058 307 3400.
