Comparison of inhibitory effect of some fungicides
against Alternaria pathogenic on grapevine
Species of Alternaria are fungi which have been recorded causing diseases on many species of agricultural crops. They are also opportunistic pathogens on numerous hosts
causing leaf spots, rots and blights on many plant parts. Diseases caused by Alternaria species are very common and are worldwide in their occurrence. Recently,
Alternaria alternata was found causing bunch rot on berries of grapevines in Slovakia*. There are several fungicides registered against diseases caused by Alternaria spp. on
various crops in our country, but until now, no fungicide is officialy authorized to control these fungi on grapevine in Slovakia.
This work was undertaken in order to evaluate the side effect of known fungicides used in vineyards against other diseases to suppress radial mycelial growth of Alternaria
alternata under in-vitro conditions.
Using of Switch ®62,5 WG in vineyards for control of grey mould can also suppress the symptomps and development of bunch rot caused by Alternaria. Although these
fungicides are mainly intended against botrytis, manufacturer report efficacy against a whole (not closer specified) berry rot complex.
However, most effective active ingredients still could be found.
This work was supported by Ministry of Agriculture and Rural Development of the Slovak Republic, contract number 381/2018/MPRV SR - 300: RPVV 15 and UOP 20 and by
AgroBioTech Research Centre built in accordance with the project Building “AgroBioTech” Research Centre ITMS 26220220180.
Alternaria alternata was isolated from symptomatic grapevine berries. It was microscopically
identified on the basis of cultural and microscopic characteristics. Pathogencity of the isolate
was estimated by infecting of healthy berries. Cultures was maintained on MA (malt agar)
medium at 4 °C before experiments.
In study, three fungicides (commercial names - Cantus® WG, Switch® 62.5WG, Tanos® 50WG)
was tested to suppress radial mycelial growth of A. alternata under in-vitro conditions. Stock
solutions of each fungicide with the same level of active ingredients (0.01 % a. i.) was prepa-
Results of trials showed, that all of the fungicides tested have some degree of concentration-dependent inhibitory effect on growth of Alternaria alternata. Comparison of
inhibitory effect of the fungicides at the same concentration (40 µl of 0.01% stock solution/12 ml agar) is shown in picture bellow. The effectivenes of fungicides decreases in
line: Switch > Cantus > Tanos; so the most effective fungicide with best side-effect against Alternaria from tested ones was Switch® 62,5 WG.
But considering that Alternaria is a very variable genus, it is quite possible that the effect of the fungicidal preparations will not be the same for each strain .
Symptoms of bunch rot on grapevine berries, caused by Alternaria in vineyards of Slovakia
1Ervín Jankura, 1Ľubica Piknová and 2Jana Štefániková
1 National Agricultural and Food Centre, Food Research Institute, Priemyselná 4, 824 75 Bratislava, Slovak Republic
2 Research Centre of AgroBioTech, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic
Kakalíková, Ľubomíra – Jankura, Ervín – Šrobárová, Antónia (2009): First report of Alternaria bunch rot of grapevines in Slovakia. Australasian Plant Disease Notes, 2009, 4, p. 68–69
Used in vineyard against:
Switch® 62,5 WG
cyprodinil 375 g/kg
fludioxonil 250 g/kg
grey mould (Botrytis cinerea)
boscalid 500 g/kg
grey mould (Botrytis cinerea)
Tanos® 50 WG
cymoxanil 250 g/kg
famoxadone 250 g/kg
downy mildew (Plasmopara viticola)
red and then incorporated into MA medium (after the medium was autoclaved) at various concentrations. Mycelial plug from the margin of actively growing culture of fungus
Alternaria alternata was inverted and transferred to the center of Petri dishes with the amended media and the control (un-amended MA medium). Trials was replicated three
times and within each trial, treatments were replicated three times at each concentration. After an incubation period 6 days at 25 °C in the dark, inhibition of mycelial growth
on the amended media were compared to the growth of mycelium in the control medium.
Control Switch® 62,5 WG Cantus® WG Tanos® 50 WG
Spores of Alternaria