OCCURRENCE OF SHARP EYESPOT (RHIZOCTONIA CEREALIS) IN WINTER TRITICALE GROWN IN SOME PROVINCES OF POLAND 1. Abstract

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1 University of Technology and Life Sciences, Bydgoszcz, Poland OCCURRENCE OF SHARP EYESPOT (RHIZOCTONIA CEREALIS) IN WINTER TRITICALE GROWN IN SOME PROVINCES OF POLAND 1 G. Lemańczyk Abstract Observations of sharp eyespot occurrence were conducted in , on commercial plantations of winter triticale, localized in the northern and central Poland. Disease index (DI)and percent of infected stems were evaluated. Significant differentiation of disease occurrence was noted in particular years. The lowest mean DI (2.12%)and mean percent of diseased stems (5.6%)was observed in 2006; while the highest one in 2009 (respectively 8.72% and 18.9%). Infected stem percentage for individual location was up to 53 in 2008 (Wichowo)and DI 21.8% in 2009 (Mochełek). On some plantations disease symptoms were not observed. Effect of previous crop, fungicide treatment or triticale cultivar on the occurrence of sharp eyespot was not noted. Presence of Rhizoctonia cerealis in damaged tissue was confirmed by mycological analysis as well as by PCR assay, while R. solani was sporadically isolated. Key words: Rhizoctonia cerealis, sharp eyespot, winter triticale, occurrence, PCR Introduction Rhizoctonia cerealis is considered the main causin agent of sharp eyespot. Its occurrence on cereals was recorded for the first time by Boerema and Verhoeven (1977). Based on morphological and cytological differences they found that the cause of this disease is new fungus species refereed to as R. cerealis (sexual stage of Ceratobasidium cereale). In Poland, for the first time, Pokacka and Wojtaszek (1977) reported the occurrence of eyespot caused by R. solani. Species R. cerealis was iso- 1 This work was supported by Grant No PB 0842/P06/2005/28 from the Polish Ministry of Science and Higher Education. Phytopathologia 56: The Polish Phytopathological Society, Poznań 2010 ISSN

2 28 G. Lemańczyk lated from rye stems by Dorenda and Dymitrow (1985)and from wheat by Truszkowska et al. (1986). It is generally recorded that sharp eyespot usually occurs at low intensity and does not cause considerable losses in cereal yield. Currently, however, on some plantations a higher intensity of the disease occurrence is observed, including also winter triticale. There are not many data on the occurrence of sharp eyespot, especially in commercial triticale plantations. That is why an attempt was made to determine its severity on this crop. The aim of the presented studies was to determine the intensity of R. cerealis infection of winter triticale stems, grown under production conditions, depending on previous crop, fungicide protection and the cultivar. Materials and methods Observations of the occurrence of sharp eyespot were carried out in , on commercial plantations of winter triticale. One hundred and three samples originating from the plantations located in six provinces were evaluated. Most of them were located in the Kujawy-Pomerania Province (74)and the Pomerania Province (23), as well as Wielkopolska (2), the West Pomerania (2), the Mazovia (1)and Lublin (1)Provinces. Detailed data concerning the origin of plant samples are shown in Table 1. At the milk stage of grain (GS 75-77; Zadoks et al. 1974), a sample of 100 randomly selected plants was collected along the diagonal of each plot. The plants were dug out from soil and pre-cleaned from soil. Under laboratory conditions, after washing and tearing off ear-bearing tillers, the percentage of stems with symptoms of sharp eyespot (Phot. 1)was evaluated. Then the intensity degree of the disease was determined, according to the following key, based on that of Cromey et al. (2002): 0 no symptoms of sharp eyespot, 1 one or more lesions on the leaf sheath, or one small spot on the stem, 2 more lesions girdling in total less than half of the stem circumference, 3 one or more lesions girdling in total at least half of the stem circumference, 4 one or more lesions girdling in total at least half of the stem circumference and stem weakened at lesions. The degrees of infection were transformed into the disease index (DI)according to the Townsend and Heuberger s formula (Wenzel 1948). The evaluation of the plants health status was supplemented by mycological analysis. Fragments of shoots with sharp eyespot symptoms were randomly cut out to confirm the presence of disease agent. The isolation was carried out according to generally assumed principles. The material was disinfected in 1% solution of AgNO 3 and placed onto PDA medium with streptomycin. The fungal isolates were exposed to preliminary determination to genus according to the mycological keys. In order to determine the Rhizoctonia genus fungi to species, their hyphae were dyed according to the method by Bandoni (1979). In order to confirm the species representation of the Rhizoctonia isolates, PCR (Polymerase Chain Reaction)with specific SCAR primers Rc2 F/R type for

3 Occurrence of sharp eyespot (Rhizoctonia cerealis) Table 1 Occurrence of sharp eyespot in plantations of winter triticale in Location Cultivar Previous crop Plant protection %/DI PCR Location Cultivar Previous crop Plant protection %/DI PCR The Kujawy-Pomerania Province 2006 Chrząstowo Sorento Witon R R 0/0 0/0 Bielawy Fidelio Ww Hortenso Ww Grenado Ww Gostycyn Fidelio Bs T2 4/1.0 Brodnica Janko O U 0/0 Gruczno Sorento Bs+Ws 0/0 Brzuchowo Fidelio Ww 5/1.3 Kończewice Witon R 3/0.8 Choceń Grenado O U 0/0 Miastowice Witon Tw T2 22/7.8 Rs Chrząstowo Gniewko Bl 7/1.8 Rc Minikowo Magnat R 1/0.3 Gałęzewo Fidelio Ww 7/1.8 Woltario Bs 10/2.5 Mochełek Fidelio R U 32/13.5 Rc Gościeradz Fidelio Bs 18/5.3 Sobiejuchy Grenado Ws 13/3.3 Moderato Ww T2 11/6.5 Jeleńcz Moderato Bs 29/10.3 Żerniki Tornado M 0/0 Kanibród Fidelio S 2/0.5 Ww T2 2/0.5 Kaźmierzewo Pawo O U 0/ Kęsowo Janko M U 1/0.3 Rc Chrząstowo Witon Bl 31/9.5 Rc Kończewice Aliko R 3/0.8 Flantrowo Fidelio Bs U 5/1.3 Rc Małocin Hortenso R U 4/1.0 Kończewice Hewo R 5/1.3 Rc Mały Fidelio Bs U 10/3.0 Minikowo Sorento R 5/1.3 Rc Mędromierz Mochełek Fidelio R U 18/5.0 Minikowo Magnat R 2/0.5 Siemoń Fidelio Tw T2 35/14.0 Rc Mochełek Tornado R U 0/0 Sobiejuchy Sorento Tw T2 6/1.5 Rc Nowa Wieś Fidelio R 0/0 Madilo O 2/0.5 Olszewka Marko Bs U 0/0 Grenado Tw 19/5.0 Moderato Bs T2 12/3.3 Padniewo Moderato Ww 38/14.5 Bs 46/21.5 Trutnowo Fidelio Bs 3/1.3 Rc Fidelio Ww 14/4.0 Tryszczyn Sorento R U 6/1.5 Papowo Moderato Ww 20/5.5 Wierzchucin Fidelio Ww U 9/3.5 Biskupie 2008 Pęchowo Baltiko Bs 4/1.0 Aleksandrów Woltario Ww 7/1.8 Pląchoty Woltario R U 40/12.5 Kujawski Płużnica Moderato Bs 2/0.5 U U U 4/1.0 6/2.3 8/2.0 Biskupin Moderato Bs 0/0

4 30 G. Lemańczyk Location Cultivar Previous crop Plant protection %/DI PCR Location Cultivar Previous crop Plant protection %/DI PCR Pręczki Woltario Ww U 0/0 Pruszcz Sobiejuchy Stary Radziejów Witon Bs Moderato Bs Grenado R Moderato O Modillo R Sorento R 0/0 2/0.5 11/3.3 8/3.5 13/3.3 7/2.0 Zorro Ww 19/6.3 Kończewo Fidelio P 1/0.3 Leśno Tornado M U 16/7.5 Rc Radostowo Magnat B 1/ Debrzno Hewo Baltiko O R T2 0/0 15/3.8 Rc Dębina Woltario Magnat R R T2 T2 11/2.8 5/1.3 Wichowo Woltario Ww 53/20.8 Rc Jerzkowice Grenado O 0/0 Wieszczyce Moderato Bs 0/0 Leśno Tornado Bs U M U Wola Bachorna Woltario Ww 3/0.8 Zamarte Moderato Bs 3/ Chrząstowo Gniewko R R U 35/15.5 Rc 37/ /5.5 4/1.0 Lipienice Magnat R 1/0.3 Lubnia Fidelio Bs 8/2.3 Wolental Moderato Bs+Ws 5/1.3 Grenado B U 1/0.5 Zielona Huta Kargo Fidelio G Bs+O U 16/4.5 7/1.8 Minikowo Grenado R 2/0.8 Mochełek Tornado R U 40/ Sławkowo Leontino P U 12/5.8 Leśno Tornado Tw U 4/1.0 P 13/7.0 The Wielkopolska Province (2008) Sobiejuchy Grenado R 8/2.3 Witrogoszcz Fidelio Bs 2/0.5 The Pomerania Province Milcz Grenado R 0/ The West Pomerania Province (2008) Brusy Fidelio Bs+O U 2/0.5 Krąpiel Grenado Bs 1/0.3 Dębina Sorento R 0/0 Suchań Fidelio M 1/0.3 Leśno Tornado Tw U 3/1.3 The Mazovia Province (2008) Rw U 1/0.5 Szewce Kazo M 9/ The Lublin Province (2006) Brusy Fidelio Bs+O U 2/0.5 Osiny Woltario Ww T2 1/0.5 Dębina Woltario R 4/1.3 Rc % percentage of stems with sharp eyespot symptoms, DI disease index (%), PCR presence of Rhizoctonia cerealis (Rc) or R. solani (Rs) confirmed by PCR assay. B beet, Bl blue lupine, Bs spring barley, G mustard, M maize, O oats, P potato, R winter rape, Rw winter rye, S serradella, Tw winter triticale, Ws spring wheat, Ww winter wheat. fungicide application at according to BBCH growth stage scale, T2 fungicide application at according to BBCH growth stage scale, U untreated (without the fungicide protection). Rs

5 Occurrence of sharp eyespot (Rhizoctonia cerealis) Phot. 1. Symptoms caused by Rhizoctonia cerealis on triticale: a two-week-old seedling, b at the milk stage of grain (photo by G. Lemańczyk) R. cerealis (Nicholson and Parry 1996)and ITS1/GMRS-3 for R. solani (Johanson et al. 1998)was carried out. The procedure was applied to selected isolates which, using conventional methods, were identified as R. cerealis or R. solani. The isolation of total DNA was performed according to the modified Doyle and Doyle method (1990). PCR reactions were made applying Core Kit (Qiagen). The obtained data were statistically analyzed with the statistical calculation package Statistica v. 8 (StatSoft Polska), using the test of single-factor analysis of variance ANOVA, with random component, at the significance level of = Prior to calculations, the data describing the number of infected treatments, expressed as percentage, were transformed into Bliss angle degree. The occurrence of the disease was tested depending on the year, previous crop, fungicide protection and cultivar. Results The results pointed at the importance of R. cerealis which was much greater than commonly believed. A greater intensity of sharp eyespot, however, differed on respective plantations. The maximum infection was observed in the case of one field in 2008, where 53% of stems were infected (Table 1). Throughout four years of re-

6 32 G. Lemańczyk Fig. 1. Sharp eyespot severity in particular years: a disease index, b percentage of stems with sharp eyespot symptoms search no symptoms of sharp eyespot were observed on 18 plantations only (out of 103 observed). The research revealed significant differences in sharp eyespot occurrence on winter triticale in respective years. The greatest number of infected stems was reported in 2009 in which there were on average on 18.9% of infected stems, and the least in % (Fig. 1). The occurrence of sharp eyespot was not considerably affected by the level of agrotechnical practices. There was no significant variation depending on the previous crop, fungicide application or cultivar (Tables 2 4). Previous crop Occurrence of sharp eyespot depending on previous crop Total Table 2 n % DI n % DI n % DI n % DI n % DI Cereals Maize Legume Cruciferous Root crops Sum/mean F-ratio ns ns ns ns ns ns ns ns ns ns p-value ns ns ns ns ns ns ns ns ns ns n number of plantations, % percentage of stems with sharp eyespot symptoms, DI disease index (%). ns not significant.

7 Occurrence of sharp eyespot (Rhizoctonia cerealis) Fungicide protection Table 3 Occurrence of sharp eyespot depending on fungicide protection Total n % DI n % DI n % DI n % DI n % DI Untreated Protection in Protection in T Sum/mean F-ratio ns ns ns ns ns ns ns ns ns ns p-value ns ns ns ns ns ns ns ns ns ns n number of plantations, % percentage of stems with sharp eyespot symptoms, DI disease index (%). fungicide application at according to BBCH growth stage scale, T2 fungicide application at according to BBCH growth stage scale. ns not significant. Occurrence of sharp eyespot depending on cultivar of triticale Cultivar Number of plantations Percentage of stems with sharp eyespot symptoms Table 4 Disease index (%) Aliko Baltiko (4 15)2.38 ( ) Fidelio (0 35)2.83 ( ) Gniewko (7 37)11.00 ( ) Grenado (0 19)1.57 ( ) Hewo (0 5)0.63 ( ) Hortenso (4 6)1.63 ( ) Janko (0 1)0.13 ( ) Kargo Kazo Leontino (12 13)6.38 ( ) Madilo Magnat (1 5)0.50 ( ) Marko Moderato (0 46)5.23 ( ) Pawo Sorento (0 13)0.89 ( ) Tornado (0 40)3.88 ( ) Witon (0 31)3.60 ( ) Woltario (0 53)4.75 ( ) Zorro In brackets range value is described.

8 34 G. Lemańczyk a Phot. 2. Confirmation of Rhizoctonia cerealis (a) and R. solani (b) with a PCR assay (photo by G. Lemańczyk) b The main causal agent of sharp eyespot was R. cerealis. Its occurrence was confirmed using traditional method, i.e. by isolation of fungi onto artificial media, where it was sporadically isolated. From stems with symptoms of sharp eyespot Rhizoctonia spp. were not always isolated. Frequently isolations yielded Fusarium spp., mainly F. avenaceum and F. culmorum. The infected tissues were also inhabited by saprotrophic fungi, from such genera as Aspergillus, Penicillium and Trichoderma. The PCR reaction with Rc2 F/Rc2 R primers confirmed the classification of selected isolates to R. cerealis, giving the expected amplification product of 850 bp (Phot. 2). By applying the molecular method, it was confirmed that in 15 randomly sampled triticale commercial plantations the occurrence of R. cerealis was unquestionable. Besides, the PCR reaction with ITS1/GMRS-3 primers confirmed the occurrence of R. solani in two fields, giving the expected product of amplification, 550 bp. Discussion Kurowski and Adamiak (2007), based on the strict experiments, inform that R. cerealis infects mainly winter cereals. Wachowska (2000)reports on the possibility of infection by the pathogen of triticale as well. According to Kurowski (2002) triticale is usually less infected by R. cerealis, compared with wheat. The observed variation in infestation between the years probably was due to prevailing weather conditions in particular years, which is reported by Żółtańska (2006)and Gill et al. (2001). According to these authors, on soils with higher moisture content a lower infection degree of cereals with R. cerealis is observed, which can result from better conditions for the development of soil saprotrophic microorganisms. It was not confirmed in our study because there was no clear correlation between the disease severity and the precipitation. The absence of such a relationship is also indicated by the observations of Daamen and Stol (1990). In this research it was only noted that in the growing seasons with the highest infestation (2007, 2009), a relatively large amount of rainfall in May and June was re-

9 Occurrence of sharp eyespot (Rhizoctonia cerealis) ported. This is confirmed by Cromey et al. (2005), who observed more sharp eyespot symptoms on irrigated winter wheat. Wiese (1987)reports that infection is primarily promoted by humidity near the stem base. Our studies showed a much greater effect of temperature. Higher level of infestation was observed during cropping seasons, characterized by a relatively warm autumn and winter. Such conditions promote development of Rhizoctonia mycelium also during this period. Pitt (1964)and Wiese (1987)reported that R. cerealis could grow even at low temperatures. Thus, the lack of frost prolonged the time in which infection and development of mycelium in the plant could have occurred. In the years when more symptoms were observed, also higher temperatures in May and June were reported. Żółtańska (2005)and Smiley and Uddin (1993)also observed in the field experiments that more sharp eyespot was present in the years of higher temperature. No effect of previous crop on the occurrence of the disease in winter cereals, including triticale, was also observed during previous studies (Lemańczyk 2006). Matusinsky et al. (2008), using PCR methods, also did not find any variability in the intensity of the R. cerealis occurrence in wheat grown after different previous crops. According to Żółtańska (2006), the infection with R. cerealis was intensified by growing cereals after cereals, which corresponded with the reports of Kurowski (2002)who isolated R. cerealis and R. solani more often when the plants were grown after the same plant. Non-cereals can be also infected with R. cerealis. Weber and Zdziebkowski (1989)as well as Wachowska (2000)noted that the pathogen, besides cereals and some grasses, can also infect rape and potato. Priyatmojo et al. (2001) also indicated the possibility of infecting sugar beet, soybean and bean. No variation was observed in the infestation intensity between cultivars. Different results were obtained by Daamen and Stol (1990), who reported significant differences in the intensity of sharp eyespot on winter wheat cultivars. Nicholson et al. (2002)reported that cultivation of less susceptible cultivars was a basic tool of limiting the disease caused by R. cerealis. Both in these studies, and in those by other authors, mainly R. cerealis was isolated from triticale stems with symptoms of sharp eyespot, and much more rarely R. solani (Kurowski 2002). Sometimes, despite clear disease symptoms, characteristic of a specific pathogen, other species secondarily infesting the infected tissues, or saprotrophic fungi are isolated (Bateman and Kwaśna 1999). Identification of Rhizoctonia species using SCAR-PCR confirms that this is an effective technique for the identification of these pathogens. Turner et al. (2001) as well as Matusinsky et al. (2008), applying specific primer type SCAR also confirmed the presence of R. cerealis in plant tissues of cereal plants. Ray et al. (2006) found that the amount of DNA of the pathogen, as compared with the total DNA obtained from the plant, increased in wheat at successive development stages. Nicholson and Parry (1996)also identified the presence of R. cerealis in single wheat stems, despite of the lack of symptoms, however, they did not always confirm the occurrence of the fungus despite clear disease symptoms.

10 36 G. Lemańczyk Conclusions 1. The intensity of sharp eyespot occurrence seems very differentiated. Number of triticale stems with the disease symptoms in commercial fields were variable in the study years (the maximum of 53% affected stems occurred, while in some plantations the disease was not reported at all). 2. Under commercial field conditions there was no significant effect of the previous crop, fungicide protection or the cultivar on the occurrence of sharp eyespot in winter triticale. 3. Rhizoctonia cerealis was the main causal agent of sharp eyespot (confirmed both with conventional and molecular method), while R. solani was only sporadically isolated. Streszczenie WYSTĘPOWANIE OSTREJ PLAMISTOŚCI OCZKOWEJ (RHIZOCTONIA CEREALIS)W PSZENŻYCIE OZIMYM UPRAWIANYM W WYBRANYCH REJONACH POLSKI Obserwacje występowania ostrej plamistości oczkowej przeprowadzono w latach , na plantacjach towarowych pszenżyta ozimego, położonych w północnej i środkowej Polsce. Określono indeks chorobowy (DI)i procent porażonych źdźbeł. Stwierdzono istotne zróżnicowanie nasilenia występowania choroby w poszczególnych latach. Najmniej objawów ostrej plamistości oczkowej obserwowano w 2006 roku, w którym średnio były one widoczne na 5,6% źdźbeł, a średnia wartość DI wynosiła 2,12%. Najwięcej objawów stwierdzono w roku 2009 średnio na 18,9% źdźbeł, a wartość DI wynosiła 8,72%. Maksymalnie na jednym polu porażeniu uległo 53% źdźbeł, co odnotowano w 2008 roku w miejscowości Wichowo, a największą wartość DI (21,8%)uzyskano w 2009 roku w miejscowości Mochełek. Na niektórych plantacjach nie obserwowano objawów choroby. Nie stwierdzono istotnego wpływu przedplonu, zastosowanej ochrony fungicydami ani odmiany pszenżyta na występowanie ostrej plamistości oczkowej. Analiza mikologiczna oraz molekularna (PCR)potwierdziły, iż Rhizoctonia cerealis był głównym sprawcą obserwowanych zmian chorobowych, natomiast znacznie rzadziej R. solani. Literature Bandoni R.J., 1979: Safranin O as a rapid nuclear stain for fungi. Mycologia 71: Bateman G.L., Kwaśna H., 1999: Effects of number of winter wheat crops grown successively on fungal communities on wheat roots. Appl. Soil Ecol. 13: Boerema G.H., Verhoeven A.A., 1977: Check-list for scientific names of common parasitic fungi. Series 26: Fungi on field crops: cereals and grasses. Neth. J. Plant Pathol. 83:

11 Occurrence of sharp eyespot (Rhizoctonia cerealis) Cromey M.G., Butler R.C., Boddington H.J., Moorhead A.R., 2002: Effects of sharp eyespot on yield of wheat (Triticum aestivum) in New Zealand. N. Z. J. Crop Hortic. Sci. 30: Cromey M.G., Butler R.C., Munro C.A., Shorter S.C., 2005: Susceptibility of New Zealand wheat cultivars to sharp eyespot. N. Z. Plant Prot. 58: Daamen R.A., Stol W., 1990: Surveys of cereal diseases and pests in the Netherlands. 2. Stem-base diseases of winter wheat. Neth. J. Plant Pathol. 96: Dorenda M., Dymitrow J., 1985: Niektóre choroby żyta uprawianego w płodozmianie zbożowym i norfolskim. Cz. II. Rocz. Nauk Roln. Ser. E 13, 1 2: Doyle J.J., Doyle J.L., 1990: Isolation of plant DNA from fresh tissue. Focus 12: Gill J.S., Sivasithamparam K., Smettem K.R.J., 2001: Effect of soil moisture at different temperatures on Rhizoctonia root rot of wheat seedlings. Plant Soil 231: Johanson A., Turner H.C., McKay G.J., Brown A.E., 1998: A PCR-based method to distinguish fungi of the rice sheath-blight complex, Rhizoctonia solani, R. oryzae and R. oryzae-sativae. FEMS Microbiol. Lett. 162: Kurowski T.P., 2002: Studia nad chorobami podsuszkowymi zbóż uprawianych w wieloletnich monokulturach. Rozpr. Hab. UW-M Olszt. 56. Kurowski T.P., Adamiak E., 2007: Occurrence of stem base diseases of four cereal species grown in long-term monocultures. Pol. J. Natur. Sci. 22, 4: Lemańczyk G., 2006: Occurrence of Rhizoctonia cerealis and Rhizoctonia solani on winter cereals under conditions of various cropping systems and depending on forecrop. In: Abstract book. 8 th Conference of the European Foundation for Plant Pathology & British Society for Plant Pathology Presidential Meeting Sustainable disease management: the European perspective. Copenhagen, 13th 17th August Programme and Abstracts P Eds. L. Munk, D.B. Collinge, D.F. Jensen. KVL, Frederiksberg, Denmark: 97. Matusinsky P., Mikolasova R., Klem K., Spitzer T., Urban T., 2008: The role of organic vs. conventional farming practice, soil management and preceding crop on the incidence of stem-base pathogens on wheat. J. Plant Dis. Prot. 115, 1: Nicholson P., Parry D.W., 1996: Development and use of a PCR assay to detect Rhizoctonia cerealis, the cause of sharp eyespot in wheat. Plant Pathol. 45: Nicholson P., Turner A.S., Edwards S.G., Bateman G.L., Morgan L.W., Parry D.W., Marshall J., Nuttall M., 2002: Development of stem-base pathogens on different cultivars of winter wheat determined by quantitative PCR. Eur. J. Plant Pathol. 108: Pitt D., 1964: Studies on sharp eyespot disease of cereals. 1. Disease symptoms and pathogenicity of isolates of Rhizoctonia solani and the influence of soil factors and temperature on disease development. Ann. Appl. Biol. 54: Pokacka Z., Wojtaszek D., 1977: Z badań nad patogenicznością Rhizoctonia solani Kühn na pszenicy i życie. Mater. XVII Ses. Nauk. Inst. Ochr. Rośl.: Priyatmojo A., Yamauchi R., Kageyama K., Hyakumachi M., 2001: Grouping of binucleate Rhizoctonia anastomosis group D (AG-D)isolates into subgroups I and II based on whole-cell fatty acid compositions. J. Phytopathol. 149: Ray R.V., Crook M.J., Jenkinson P., Edwards S.G., 2006: Effect of eyespot caused by Oculimacula yallundae and O. acuformis, assessed visually and by competitive PCR, on stem strength associated with lodging resistance and yield of winter wheat. J. Exp. Bot. 57, 10: Smiley R.W., Uddin W., 1993: Influence of soil temperature on Rhizoctonia root rot (R. solani AG 8 and R. oryzae) of winter wheat. Plant Dis. 76: Truszkowska W., Dorenda M., Kutrzeba M., 1986: Mikroflora jako czynnik ochrony pszenicy przed chorobami podstawy źdźbła powodowanymi przez grzyby, w zależności od warunków ekologicznych. Acta Mycol. 22, 2: Turner A.S., Nicholson P., Edwards S.G., Bateman G.L., Morgan L.W., Todd A.D., Parry D.W., Marshall J., Nuttall M., 2001: Evaluation of diagnostic and quantitative PCR for the identification and severity assessment of eyespot and sharp eyespot in winter wheat. Plant Pathol. 50: Wachowska U., 2000: Susceptibility of cereals and other crops to Rhizoctonia cerealis. Phytopathol. Pol. 20: Weber Z., Zdziebkowski T., 1989: Podatność zbóż, rzepaku i ziemniaka na Rhizoctonia cerealis i R. solani. Mater. XXIX Ses. Nauk. Inst. Ochr. Rośl. Część II:

12 38 G. Lemańczyk Wenzel H., 1948: Zur Erfassung des Schadenausmasses in Pflanzenschutzversuchen. Pflanzenschutz-Ber. 15: Wiese M.V., 1987: Compendium of wheat diseases. APS Press, St. Paul, Minnesota. Zadoks J.C., Chang T.T., Konzak C.F., 1974: A decimal code for the growth stages of cereals. Weed Res. 14: Żółtańska E., 2005: The effect of previous crop and weather conditions on the incidence of stem base diseases in winter wheat. J. Plant Prot. Res. 45, 1: Żółtańska E., 2006: The effect of soil moisture and temperature on efficacy of seed dressing preparations Biochikol 020 PC and Baytan Universal 19,5 WS in control of Rhizoctonia fungi on wheat. J. Plant Prot. Res. 46, 3: Author s address: Dr. Grzegorz Lemańczyk, Department of Phytopathology and Molecular Mycology, University of Technology and Life Sciences, ul. Kordeckiego 20, Bydgoszcz, Poland, Grzegorz.Lemanczyk@utp.edu.pl Accepted for publication: