Roczniki Akademii Rolniczej w Poznaniu CCCLXXXIII (2007) DOROTA SZOPIŃSKA, HANNA DORNA, KRYSTYNA TYLKOWSKA THE EFFECTS OF GRAPEFRUIT EXTRACT ON GERMINATION, VIGOUR AND HEALTH OF CABBAGE, ONION AND ZINNIA SEEDS From Department of Horticultural Seed Science and Technology August Cieszkowski Agricultural University of Poznań ABSTRACT. Cabbage, onion, and zinnia seeds were soaked in Biosept 33 SL (a.i. grapefruit extract 33%) solutions at concentrations of 0.05 and 0.25%. Sarfun T 65 DS was applied as a chemical control agent. Biosept 33 SL improved germination capacity of cabbage and onion seeds at 10 C and accelerated germination of cabbage seeds at 10 and 20 C. In most cases, the preparation controlled fungi on seeds of the examined species as effectively as the fungicide used or even to a larger extent. The results showed that fungicides used for pre-sowing treatments of cabbage and onion seeds could be replaced by Biosept 33 SL. Key words: Biosept 33 SL, grapefruit extract, cabbage seeds, onion seeds, zinnia seeds, seed treatment Introduction Seeds infested with pathogenic fungi are often the main source of plant diseases. Alternaria brassicicola (Schw.) Wilts. and Fusarium spp. have been recorded as seedborne pathogens of cabbage, Botrytis aclada Fresen. (syn. B. allii Munn), B. cinerea Pers. ex. Fr. and Fusarium spp. as seed-borne pathogens of onion, whereas Alternaria zinniae M. B. Ellis and B. cinerea Pers. ex Pers. as seed-borne pathogens of zinnia (Richardson 1990). Alternaria alternata (Fr.) Keissler is a very common cosmopolitan species, which being a facultative parasite, may quickly change itself into a pathogenic one and accelerate the occurrence and intensity of disease on certain plants (Kwaśna 1992). A. alternata and A. brassicicola cause dark leaf spot in cultivated brassicas world-wide (Tylkowska et al. 2004). B. aclada and B. cinerea cause grey mould and neck rot of onion bulbs (Tylkowska and Dorna 2001). A. zinniae causes Alternaria blight in zinnia whereas B. cinerea grey mould (Richardson 1990). Rocz. AR Pozn. CCCLXXXIII, Ogrodn. 41: 631-636 Wydawnictwo Akademii Rolniczej im. Augusta Cieszkowskiego w Poznaniu, Poznań 2007 PL ISSN 0137-1738
632 D. Szopińska, H. Dorna, K. Tylkowska Seeds are commonly treated with chemicals. The use of plant origin preparations, instead of fungicides, to control seed-borne pathogenic fungi seems an attractive alternative, especially for organic farming. It was proved that extract from grapefruit seeds included many microbial inhibitory compounds (Liu et al. 1990, Angioni et al. 1998, Niedworok 2000). The aim of the study was to determine the effects of grapefruit extract on germination, vigour and health of cabbage, onion and zinnia seeds. Materials and methods Seeds of cabbage (Brassica oleracea L.) cv. Brunświcka, onion (Allium cepa L.) cv. Sochaczewska and zinnia (Zinnia elegans Jacq.) cv. Orys were obtained from Seed Company CNOS in Poznań. Plant origin preparation Biosept 33 SL (a.i. grapefruit extract 33%), produced by Cintamani, Poland, was applied in the experiment. Sarfun T 65 DS (a.i. 20% carbendazim and 45% thiram) was used as a fungicide control. Seeds were soaked in 0.05 and 0.25% Biosept 33 SL solution for 30 min or were treated with the fungicide at dosages: 3 g per 1 kg of cabbage seeds or 5 g per 1 kg of onion and zinnia seeds. Seed germination tests were performed according to the International Rules for Seed Testing (1999) at 10 and 20 C. Seed vigour was described by means of T 1 (time to 1% of the total number of germinating seeds) and T 50 (time to 50% of the total number of germinating seeds) values (Dorna et al. 2005 b). Deep-freezing blotter test was applied to evaluate the health of cabbage and zinnia seeds, whereas agar test for onion seeds (Tylkowska and Dorna 2000). Seed health was evaluated at 20 C. Results and discussion Treating cabbage and onion seeds with Biosept 33 SL and Sarfun T 65 DS significantly improved their germination capacity and decreased the number of diseased seedlings and dead seeds at 10 C. Biosept 33 SL at higher concentration and the fungicide increased also germination capacity of onion seeds at 20 C. In general, considerably lower number of diseased seedlings was observed at 20 C after Biosept 33 SL and fungicide treatments of cabbage and onion seeds (Table 1). Neither Biosept 33 SL nor the fungicide improved germination capacity of zinnia seeds. The effect of Biosept 33 SL treatments on the incidence of diseased seedlings and dead seeds was differentiated in the latter species (tab. 1). Soaking cabbage seeds in Biosept 33 SL solutions accelerated their germination at 10 and 20 C. In general, the preparation had no effect on onion seed vigour, but influenced negatively this parameter for zinnia seeds at 20 C (Tab. 2). All treatments improved seed health of the species examined. Biosept 33 SL controlled growth of A. alternata and A. brassicicola to a larger extent than Sarfun T 65 DS. In case of A. zinniae on zinnia seeds and B. aclada and B. cinerea on onion seeds, the preparation was as effective as the fungicide. Biosept 33 SL decreased the incidence of Fusarium spp. on cabbage and onion seeds, however was not effective against these
The effects of grapefruit extract on germination... 633 Table 1 Effects of cabbage, onion and zinnia seed treatment on their germination at 10 and 20 C Wpływ sposobu traktowania na kiełkowanie nasion kapusty, cebuli i cynii w temperaturze 10 i 20 C Seed treatment Sposób traktowania nasion germination capacity zdolność kiełkowania 10 C 20 C diseased seedlings siewki porażone dead seeds nasiona martwe Cabbage Kapusta germination capacity zdolność kiełkowania diseased seedlings siewki porażone dead seeds nasiona martwe C 1) 58.0 b* 13.3 a 4.3 a 63.3 b 22.7 a 4.0 a F I 2) 89.0 a 6.7 b 0.7 b 75.0 a 10.3 b 1.7 ab B I 3) 90.0 a 0.3 b 1.0 b 72.0 ab 13.7 b 2.0 ab B II 4) 91.3 a 2.3 b 1.0 b 67.0 ab 14.7 ab 0 b Onion Cebula C 31.3 c 11.0 a 13.7 a 74.3 b 13.3 a 4.0 a F II 5) 55.7 b 4.0 b 0 c 88.7 a 3.0 c 1.3 b B I 55.3 b 4.3 b 3.3 b 81.0 b 6.0 b 4.0 a B II 77.7 a 0.3 c 3.0 b 87.7 a 2.0 c 2.7 ab Zinnia Cynia C 5.3 a 7.3 bc 48.0 a 20.3 bc 53.0 a 20.0 b F II 6.3 a 4.3 c 4.0 d 29.3 ab 26.7 c 1.0 c B I 2.3 b 11.7 a 24.0 b 14.7 c 55.0 a 27.3 ab B II 3.3 a 10.3 ab 10.3 c 21.7 abc 33.0 b 31.3 a 1) Control, 2) Sarfun T 65 DS 3 g/kg seeds, 3) Biosept 33 SL at 0.05% concentration, 4) Biosept 33 SL at 0.25% concentration, 5) Sarfun T 65 DS 5 g/kg seeds. *For each species values in columns followed by the same letters are not significantly different according to Duncan s multiple new range test (α = 0.05). 1) Kontrola, 2) Sarfun T 65 DS 3 g/kg nasion, 3) Biosept 33 SL w stężeniu 0,05%, 4) Biosept 33 SL w stężeniu 0,25%, 5) Sarfun T 65 DS 5 g/kg nasion. *Dla każdego gatunku, wartości w kolumnach oznaczone tymi samymi literami nie różnią się istotnie według testu Duncana (α = 0,05). fungi on zinnia seeds (tab. 3). Dorna et al. (2004) found that Citrosept, plant origin preparation based on grapefruit extract, controlled fungi on onion seeds as effectively as fungicides applied, but had no effect on germination and vigour of onion seeds. It has been also reported that this preparation inhibited the growth of several fungi, isolated from cabbage, carrot and onion seeds, among them: A. alternata, A. brassicicola, B. aclada, B. cinerea, Fusarium avenaceum and F. oxysporum (Dorna et al. 2005 a). The antifungal activity of grapefruit extract has been confirmed previously (Orlikowski 2001, Orlikowski and Skrzypczak 2001).
634 D. Szopińska, H. Dorna, K. Tylkowska Table 2 Effects of cabbage, onion and zinnia seed treatment on their vigour at 10 and 20 C Wpływ sposobu traktowania na wigor nasion kapusty, cebuli i cynii w temperaturze 10 i 20 C Seed treatment Sposób traktowania nasion T 1 6) 10 C 20 C T 50 7) T 1 T 50 Cabbage Kapusta C 1) 3.96 a* 4.53 a 1.17 a 1.68 a F I 2) 3.08 b 4.12 b 1.04 ab 1.48 b B I 3) 2.14 d 3.63 c 0.98 ab 1.24 c B II 4) 2.50 c 3.74 c 1.15 a 1.44 bc Onion Cebula C 2.71 a 4.91 a 1.50 a 2.33 a F II 5) 2.41 a 4.77 ab 1.43 a 2.46 a B I 2.81 a 4.54 b 1.54 a 2.46 a B II 2.60 a 4.69 ab 1.40 a 2.34 a Zinnia Cynia C 2.77 ab 5.58 b 0.88 a 1.80 c F II 2.97 a 6.56 a 0.74 ab 2.58 a B I 1.74 bcd 4.96 c 0.62 ab 2.16 b B II 1.44 cd 5.13 bc 0.61 ab 2.48 a 6) time to 1% of the total number of germinating seeds, 7) time to 50% of the total number of germinating seeds. For other explanations: see Table 1. 6) czas potrzebny do wykiełkowania 1% z ogólnej liczby kiełkujących nasion, 7) czas potrzebny do wykiełkowania 50% z ogólnej liczby kiełkujących nasion. Pozostałe objaśnienia: patrz tabela 1. The results obtained suggest that Biosept 33 SL can replace fungicides in presowing treatments of cabbage and onion seeds. Conclusions 1. Grapefruit extract significantly improved germination capacity of cabbage and onion seeds at 10 C and accelerated germination of cabbage seeds at 10 and 20 C. 2. The preparation effectively controlled most of the pathogenic fungi occurring on cabbage, onion and zinnia seeds.
The effects of grapefruit extract on germination... 635 Effects of cabbage, onion and zinnia seed treatment on their health Wpływ sposobu traktowania na zdrowotność nasion kapusty, cebuli i cynii Table 3 Species Gatunek Seed treatment Sposób traktowania nasion The percentage of seeds infested with Odsetek nasion opanowanych przez Cabbage Kapusta Onion Cebula Zinnia Cynia Alternaria alternata Alternaria brassicicola Fusarium spp. C 1) 96.5 a* 77.0 a 8.0 a F I 2) 50.5 b 37.5 b 0 b B I 3) 4.0 c 2.0 c 0.5 b B II 4) 2.5 c 1.5 c 0 b Botrytis aclada Botrytis cinerea Fusarium spp. C 21.5 a 6.0 a 1.0 a F II 5) 1.5 b 0 b 0 b B I 6.0 b 0 b 0 b B II 4.0 b 0 b 0 b Alternaria zinniae Botrytis cinerea Fusarium spp. C 54.0 a 6.5 a 37.0 a F II 38.0 bc 0 c 2.0 b B I 43.5 b 3.5 b 37.5 a B II 31.0 c 6.0 a 38.0 a Explanations: see Table 1. Objaśnienia: patrz tabela 1. References Angioni A., Cabras P., Hallewin G., Pirisi F. M., Reniero F., Schirra M. (1998): Synthesis and inhibitory activity of 7-geranoxycoumarin against Penicillium species in Citrus fruit. Phytochemistry 47, 8: 1521-1525. Dorna H., Tylkowska K., Shan Wenyan, Szopińska D. (2004): Wpływ preparatów pochodzenia roślinnego na zdrowotność, kiełkowanie i wigor nasion oraz wschody cebuli (Allium cepa L.). Folia Univ. Agric. Stetin. 239, Agric. 95: 69-74. Dorna H., Tylkowska K., Szopińska D., Wasilewska D., Zieliński G. (2005 a): Effects of plant origin preparations on the growth of fungi isolated from seeds of selected vegetables. In: Modern Fungicides and Antifungal Compounds IV. Eds. H.W. Dehne, U. Gisi, K.H. Kuck, P.E. Russel, H. Lyr. BCPC, Alton, UK: 293-299. Dorna H., Tylkowska K., Wei Yahong, Marcinek R. (2005 b): Germination and health of onion (Allium cepa) seeds after priming combined with chemical or biological treatments. Phytopathol. Pol. 37: 69-81. International Rules for Seed Testing (1999): Seed Sci. Technol. 27.
636 D. Szopińska, H. Dorna, K. Tylkowska Kwaśna H. (1992): Occurrence of Alternaria species in Poland. In: Alternaria: Biology, Plant Diseases and Metabolites. Eds J. Chełkowski, A. Visconti. Elsevier Science Publishers B.V., Amsterdam, London, New York, Tokyo: 301-336. Liu Y.B., Alford A.R., Rajab M.S., Bentley M.D. (1990): Effects and modes of action of citrus limonoides against Leptinotarsa decemlineata. Physiol. Entomol. 15, 1: 37-45. Niedworok J. (2000): Sok grejpfrutowy a działanie leków. Wiad. Zielar. 10: 10-11. Orlikowski L.B. (2001): Effect of grapefruit extract on development of Phytophthora cryptogea and control of foot rot of gerbera. J. Plant Prot. Res. 41, 3: 288-294. Orlikowski L.B., Skrzypczak Cz. (2001): Biopreparat z wyciągu z grejpfruta postęp w biologicznej ochronie roślin przed chorobami. Ann. Univ. Mariae Curie-Skłodowska Sect. EEE, Hortic. 9: 261-269. Richardson M.J. (1990): An annotated list of seed-borne diseases. International Seed Testing Association. Zűrich, Switzerland. Tylkowska K., Dorna H. (2000): Effects of carrot, cauliflower and onion seed treatment with plant material or fungicides on the incidence of seed-borne pathogenic fungi. Rocz. AR Pozn. 232, Ogrodn. 31, 1: 527-532. Tylkowska K., Dorna H. (2001): Onion (Allium cepa) seed and plant health with special reference to Botrytis allii. Phytopathol. Pol. 21: 55-68. Tylkowska K., Korbas M., Kurzawińska H., Rataj-Guranowska M. (2004): Objawy chorób powodowanych przez grzyby rodzaju Alternaria. In: Kompendium symptomów chorób roślin oraz morfologii ich sprawców. Ed. M. Rataj-Guranowska. Inst. Ochr. Rośl. Bank Patogenów Roślin, Poznań: 3-22. WPŁYW EKSTRAKTU Z GREJPFRUTA NA KIEŁKOWANIE, WIGOR I ZDROWOTNOŚĆ NASION KAPUSTY, CEBULI I CYNII Streszczenie Celem doświadczenia było zbadanie wpływu zaprawiania ekstraktem z grejpfruta nasion kapusty, cebuli i cynii na ich kiełkowanie i wigor oraz zasiedlenie przez grzyby. Nasiona moczono przez 30 minut w 0,05 i 0,25-procentowym roztworze preparatu Biosept 33 SL (s. a. ekstrakt z grejpfruta, 33%) lub zaprawiano na sucho preparatem Sarfun T 65 DS. Zdolność kiełkowania i wigor nasion określano w temperaturze 10 i 20 C. Zdrowotność nasion oceniano w temperaturze 20 C, dla kapusty i cynii za pomocą testu bibułowego z przemrażaniem, a dla cebuli w teście agarowym. Ekstrakt z grejpfruta istotnie poprawił zdolność kiełkowania nasion kapusty i cebuli w temperaturze 10 C oraz przyspieszał kiełkowanie nasion kapusty w obu temperaturach. Preparat ten bardziej niż Sarfun T 65 DS ograniczał występowanie A. alternata i A. brassicicola na nasionach kapusty oraz był równie skuteczny jak fungicyd w zwalczaniu A. zinniae na nasionach cynii oraz B. aclada i B. cinerea na nasionach cebuli.