000 02755nab a22003977a 4500
001 G75039
003 MX-TxCIM
005 20211006080755.0
008 121211b |||p||p||||||| |z||| |
022 0 _a0931-1785
040 _aMX-TxCIM
082 0 4 _a92-095251
100 1 _aTiedemann, A. v.
245 0 0 _aOzone effects on fungal leaf diseases of wheat in relation to epidemiology. 2. Biotrophic pathogens
260 _c1992
340 _aPrinted
500 _a4 ill., 2 tables; 14 ref. Summaries (De, En)
520 _aWheat plants of four different growth stages (tillering, stem elongation, ear emergence and anthesis) were exposed to 80, 160 and 240 mig m(-3) ozone for 5 days (7 h per day) and to charcoal-filtered air. After exposure, plants were inoculated with conidia of Erysiphe graminis f. sp. tritici or uredospores of Puccinia recondita f. sp. tritici. The number of powdery mildew colonies and the amount of conidia formed on the two upper leaf positions was significantly increased on plants at young growth stages (GS 21 and 37) after moderate fumigations with ozone (80-160 mig m(-3)). However, at 240 mig m(-3) ozone, mildew attack was significantly reduced. On mature plants (GS 55), infection frequency and sporulation were decreased by all ozone treatments. Leaf rust was enhanced by ozone at all growth stages, the effects being stronger with increasing developmental stages. On younger plants (GS 29 and 51), however, the highest ozone variants reduced rust severity, whereas on older plants the two highest ozone levels induced the highest disease severity. These results were obtained equally for the number of rust pustules and the amount of produced uredospores. The latent period of both pathogens was not significantly affected by ozone. It is concluded that under elevated ozone pollution in the field, mildew epidemics may be accelerated in the early season, however associated with a premature breakdown due to adult-plant resistance, whereas leaf rust may be enhanced until maturity of the plants. Overall, under the influence of ozone a premature shifting within the pathogenic population from mildew to rust and to necrotrophic pathogens may be expected
546 _aEnglish
595 _aAC
650 1 0 _aAscomycotina
650 1 0 _aBasidiomycotina
650 1 0 _aBiological properties
650 1 0 _aErysiphales
650 1 0 _aErysiphe
650 1 7 _aFungi
_gAGROVOC
_2
_91121
650 1 0 _aGramineae
650 1 0 _aMicrobial properties
650 1 0 _aOxidants
650 1 7 _aPlant diseases
_gAGROVOC
_2
_91206
650 1 0 _aPuccinia
650 1 0 _aUredinales
650 1 7 _aTriticum
_gAGROVOC
_2
_91295
773 0 _tJournal of phytopathology (Germany, F.R.). (1992). v. 134(3) p. 187-197
942 _cJA
999 _c22189
_d22189