The effects of growth regulators on spring barley (Hordeum vulgare L.) morphological indicators and grain contamination with fungi and mycotoxins

S. Supronienė, O. Auškalnienė, Z. Dabkevičius and A. Mankevičienė

Lithuanian Institute of Agriculture, Instituto str. 1, LT–58344 Akademija, Kedainiu distr.,Lithuania; e-mail: skaidre@lzi.lt, ona@lzi.lt,

Abstract:

The effects of growth regulators Modus 250 EC (trinexapac–ethyl 250 g l-1) and Cerone 480 (etefon 480 g l-1) on the morphological characteristics of the spring barley varieties Henni and Luokė and on grain contamination with fungi and mycotoxins were studied at the Lithuanian Institute of Agriculture in 2004 and 2005.Spring barley was sprayed with the retardant Modus at growth stages 32–33 BBCH andwith the retardant Cerone at – 39–43 BBCH. Plant morphological measurements were made before harvesting. Percent of internal grain contamination with fungi was determined. The concentrations of the mycotoxins deoxynivalenol (DON), T-2 toxin and zearalenone (ZEN) in grain were measured by ELISA method, using Neogen diagnostic mycotoxin determination tests.The retardants reduced plant height from 66.0 to 58.0 cm, length of the last node from19.4 to 17.9 cm for the variety Henni, and from 74.1 to 63.8 cm, and from 22.4 to 16.9 cm, respectively, for the variety Luokė compared with the unsprayed plants.The content of Fusarium-affected grain in the retardant-sprayed and not appliedtreatments was similar, however, Fusarium avenaceum (Fr.) Sacc was more prevalent in the barley sprayed with retardants. F. avenaceum, F. sporotrichioides Sherb., F. poae (Peck) Wollenw, F. tricinctum (Corda) Sacc., F. culmorum (W. G. Smith) Sacc. dominated in the grain samples in 2005.The contents of DON, ZEN and T-2 toxin determined were low, however, higher contentswere identified for barley sprayed with the retardants.

Key words:

Fusarium fungi as potential toxicants on cereals and grain feed grown in Estonia during 1973–2001

H. Lõiveke¹, H. Laitamm² and R.-J. Sarand²

¹Estonian Research Institute of Agriculture, Teaduse 4, Saku, 75501 Harjumaa, Estonia; e–mail: heino.loiveke@mail.ee
²Estonian Control Centre of Plant Production, Teaduse 4/6, Saku, 75501 Harjumaa, Estonia; e-mail: riho.sarand@tmkk.ee

Abstract:

This study was carried out to investigate the occurrence of the genus Fusarium Link ex Fr. on cereal grain grown in Estonia and grain feeds made of the named cereal grain. Within the period of 1973–1981, occurrence of genus Fusarium was identified in 1,065 grain seed samples, and, within 1997–2001, in 29 samples of grain feed.Fusarium sp. was identified in 67–100% of the studied wheat samples, and, depending on the year, infection was detected in 13–67% of the seeds. In the case of rye,Fusarium species were identified in 38–86% of the studied samples and infection was found in 8–23% of the seeds, with barley the figures were 45–97% and 14–46%; and oats 55–100% and 15–65%, respectively.
The study indicated that the infection spread more intensively when corn was lodged, as a result of rainy autumn and late harvest. 16 species and 4 varieties of Fusariumwere found on seeds. According to the survey (in 707 samples), the most common species were the following: F. avenaceum (Fr.) Sacc., F. poae (Pk.) Wr., F. oxysporum(Schlecht) Snyd. et Hans., F. ventricosum App. et Wr., F. sporotrichioides Sherb. var. minus Wr., F. verticillioides (Sacc.) Nirenberg and F. culmorum (W.G.Sm) Sacc. Mycotoxin producing species F. avenaceum, F. poae, F. sporotrichioides, F. oxysporum, F. verticilliodes, F. sambucinum Fuck., F. equiseti (Corda) Sacc. and F. culmorumwere detected in 50–60% of the studied samples. As a result of the studies on domestic grain feed (29 samples) carried out within 1997–2001, Fusarium spp. was found in 51.7% of the samples, whereas Fusarium toxins were detected in seven samples out of nine. 31.3% of Fusarium isolates were highly toxic, and 37.5% were toxic on Bacillus stearothermophilus. One isolate of F. verticillioides, one of F. culmorum, F. tricinctum (Corda) Sacc. and two of F. sp. proved to be highly toxic.

Key words:

Bacillus stearothermophilus, cereal grain, Fusarium fungi, grain feed, mycotoxins, seed infection