INVESTIGATION OF THE EFFECT OF MALT AND PLANT EXTRACTS ON DIFFERENT PLANT PATHOGENSS|
Jenő HODONYI1, Gabriella KAZINCZI2, József BAKONYI3, Ernő TYIHÁK3, Árpád SZÉCSI3, József HORVÁTH4, Richard GÁBORJÁNYI4, András TAKÁCS2
1Sächsische Malzindustrie und Nährmittelfabrik GmbH, D-01909 Großhartau, Dresdner Str. 27, Germany
2Office for Academy Research Groups Attached to Universities and Other Institutions, Virology Group, University of Veszprém, Georgikon Faculty of Agricultural Sciences, H-8361 Keszthely, P.O.Box 71, Hungary
3Plant Protection Institute of Hungarian Academy of Sciences, H-1525 Budapest, Herman Otto u. 15, Hungary
4University of Veszprém, Georgikon Faculty of Agricultural Sciences, H-8361 Keszthely, P.O.Box 71, Hungary (contact e-mail: email@example.com)
Malt has an importance in food industry. Because of its complex behavior its seems to be wery plausible that biological activity could some role in the plant protection. Natural chemicals and their use for integrated plant protection is one of the focuses of research works all over the world (Duke et al. 2002). These compounds could be used against different phytopathogen fungi (Orlikowski 2001). and their effects are also known to inhibit the spread and replication of viruses and to reduce the virus concentration in the infected leaves (Smookler 1971, Baranwal and Verma 1997, Manickam and Rajappan 1998, VIVANCO et al. 1999).
Experiments were carried out in order to study the effect of malt and plant extracts on plant growth, plant-virus interaction and phytopathogen fungi under laboratory conditions.
Material and methods
The effect of the malt samples and different extracts (No. 1-14) have been studied to phytopathogen fungi (Phytophthora infestans, Alternaria alternata, Botrytis cinerea, Sclerotinia sclerotiorum, Fusarium avenaceum, F. culmorum, F. graminearum, F. moniliforme, F. sambucinum) in petri dishes (Table 1). Fusarium species were growing to 7 days in dark at 25oC on potato-dextrose agar. Phytophthora infestans, Alternaria alternata, Botrytis cinerea and Sclerotinia sclerotiorum were maintained on pea-agar. The agar-plates with malt extracts were inoculated with disc (5 mm) fungi-gel cultures. After the treatment petri-dishes were kept in dark at 25oC. The diameters of the fungal thalli were measured after 24 and 72 hours.
Table 1. The studied malt samples and plant extracts
|Sample No||Malt samples and different extracts ||dilution (g/l)|
|2||Wheat : Barley malt 50 : 50||40-80|
|3||Wheat : Barley malt 70 : 30||40-80|
|4||Wheat germ 10 %||43-85|
|5||Wheat germ 15 %||41-81.5|
|6||Rye : Barley malt 50 : 50||3.5-5.5|
|7||Rye : Barley malt 70 : 30||3.5-5.5|
|8||Rye : Barley malt 30 : 70||5.5|
|9||Nettle - Malt extract 18 : 85 thickness 73 %||80|
|10||Coffee - Malt extract||60|
|11||Walnut leaf - Barley malt concentrate thickness 80 %||50|
|12||Malt concentrate - Peppermint||80|
|13||Onion oil extract - Barley malt||6.5|
|14||Garlic extract - Barley malt||6.5|
|15||Grape-vine leaf - Nettle leaf - Malt extract||7.5|
|16||Elderpith - Nettle leaf - Malt extract||7.5|
|17||Plantain - Malt extract||7.5|
|18||Pigweed - Malt extract||7.5|
The plant growth and virus susceptibility were studied in potato cv. Desiree, tomato cv. Manó and tobacco cv. Xanthi-nc in pot experiments. Potato-Potato virus Y (PVY), cucumber-Zucchini yellow mosaic virus (ZYMV), tomato-Cucumber mosaic virus (CMV), tobacco-Tomato spotted wilt virus (TSWV) and tobacco-CMV plant-virus interactions were studied. Tobacco, potato, tomato plants were infected at 6-8 leaf stages and cucumber plants at cotyledonous. Plants were treated (the soil was treated by malt solution, the plants were sprayed, or soil treatments and plant sprays together) two times per weak with different malt samples and plant extracts (No. 1-18). Two month later fresh weight of the plants and virus susceptibility by DAS-ELISA serological method after Clark and Adams (1977) were measured.
Results and discussion
The samples No. 13 and 14 (dilution 160 g/l) were reduced the growth of all Fusarium species by about 50 % and the samples 1, 4, 5, 6, 9, 11, 12, 13 and 14 inhibited the growth of P. infestans by 100 %. In some cases the malt samples were not enough effective or had stimulatory effect to some fugal species. In our experiments the P infestans, A. alternata and B. cinerea species were the most sensitive to treatments. However S. sclerotiorum were stimulated by majority the most malt samples. Among the malt samples the No. 3, 4, 5, 6, 11, 12, 13, and 14 showed the most strongest (22-34%) inhibitory effect (Table 2).
Table 2. The inhibitory effect of malt samples and plant extracts to growth of thallus (%)
|Samples||Pathogens and Malt concentrations|
|Phythophthora infestans||Alternaria alternata||Botrytis cinerea||Sclerotinia sclerotiorum|
In some cases malt samples stimulated the plant growth in the pot experiments. Except No. 14, all malt samples increased the fresh weight all of the tested plants. The pigweed - malt extract (No. 18) inhibited the ZYMV infection of the cucumber test plants in all cases. Malt extracts mixed with other plant component reduced the virus infection, showing the additional virus inhibitory effect of the plant extracts.
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