The effects of nitrogen rates and intercropping on the occurrence of Fusarium spp. on barley kernels

E. Akk¹,*, T.E. Søndergaard², J.L. Sørensen², H. Giese², M.L. Kütt⁵, L. Edesi³, H. Lõiveke¹ and E. Lauringson⁴

¹ Estonian Crop Research Institute, Department of Plant Protection, J. Aamisepa 1, 48309, Jõgeva, Estonia
² Aalborg University, Department of Chemistry and Bioscience, Fredrik BajersVej 7H, 9000 Aalborg, Denmark
³ Estonian Crop Research Institute, Department of Agrotechnology, J. Aamisepa 1, 48309, Jõgeva, Estonia
⁴ Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Kreutzwaldi ⁵, 51014 Tartu, Estonia
5University of Vienna, Department of Food Chemistry and Toxicology, Währinger Straβe 38, 1090, Wien, Austria
*Correspondence: elina.akk@etki.ee

Abstract:

The aim of the field experiments was to compare the effect of nitrogen rates and intercropping on the occurrence of Fusarium spp. in barley kernels. The experiments were performed in Central Estonia (58 ̊33´N, 25 ̊34´E) in 2009 and 2010. The composition of fungi in spring barley kernels was found through isolation and subsequent sequence analyses of the internal transcribed spacer (ITS) region and morphological features. During the study, 13 species of micro-fungi were identified in the grain samples. The most common species of fungi found in barley were Fusarium avenaceum, Fusarium poae, as well as Phoma pinodella. The compositions of pathogenic fungi on Estonian barley kernels were affected by the level of nitrogen fertilization and growing on barley-pea intercropping. The study showed tendencies that barley-pea intercropping had fewer occurrences of Fusarium species than sole barley.

Key words:

Fusarium spp., intercropping, nitrogen rates, spring barley

Incidence of Fusarium spp. on several field crops in Estonia and their toxicity towards Bacillus stearothermophilus

H. Lõiveke

Estonian Research Institute of Agriculture, Teaduse 13, EE75501 Saku, Harjumaa, Estonia;e-mail: heino.loiveke@eria.ee

Abstract:

The article provides an overview of the occurrence of Fusarium spp. on grain produced in Estonia from 1973–2004, the occurrence of Fusarium spp. in the common root rot complex of cereals in 1977–1985 and potato tubers with dry rot symptoms in the yield of 1996–2000. The dominating species on grain were (contaminated samples, %) F. avenaceum (Fr.) Sacc. – 28.0–30.3; F. poae (Pk.) Wr. – 7.4–9.5 F. semitectum Berk. et Rav. – 7.0–9.0; F. oxysporum (Schlecht) Snyd. et Hans. – 7.4-8.0; accompanied by F. ventricosum App. et Wr., F. sporotrichioides Sherb. var. minus Wr., F. verticillioides (Sacc.) Nirenberg, F. culmorum (W. G. Sm.) Sacc. and F. sambucinum Fuck. In the common root rot complex of barley, F. culmorum – 16.8; F. sambucinum – 2.5; F. avenaceum – 2.2; F. oxysporum – 1.7; and F. poae – 1.3 (contaminated samples, %) dominated. In potato with dry rot, F. culmorum – 26.7; F. solani (Mart.) Sacc. – 20.0; F. poae – 15.0; F. oxysporum – 13.3 and F. sulphureum Schlecht – 8.3 (contaminated tubers, %) dominated. The occurrence of toxic isolates both on grain and potato was established. Of Fusarium isolates recovered from grain (total 287) 5.6% were highly toxic, and 88.1% mildly or medium toxic to Bacillus stearothermophilus. Of 15 isolates found on potato, 1 was highly toxic and 9 were mildly to medium toxic. Fusarium spp. has been presented according to Gerlach & Nirenberg (1982).

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