G. Schmiedeknecht et al., Use of Bacillus subtilis as biocontrol agent. V. Biological control of diseases on maize and sunflowers, Z PFLANZENK, 108(5), 2001, pp. 500-512
Citations number
49
Categorie Soggetti
Plant Sciences
Journal title
ZEITSCHRIFT FUR PFLANZENKRANKHEITEN UND PFLANZENSCHUTZ-JOURNAL OF PLANT DISEASES AND PROTECTION
The effect of different environmental conditions on plant growth-promoting
and antifungal activities of two different Bacillus subtilis strains were s
tudied. For this purpose, the bacteria isolated and commercialized by FZB B
iotechnik GmbH Berlin were tested for their in vitro and in vivo performanc
es. First, the strains were screened for their antagonistic abilities again
st phytopathogenic fungi of maize and sunflowers. It was found that antifun
gal activities varied according to the composition of the assay medium, pH
and temperature value. Low iron availability in the assay medium increased
bacterial competition for this element and resulted further in a higher ant
ifungal activity. Further, it was found that different nitrogen sources aff
ected differently growth and spore production by B. subtilis strains. Highe
r growth and spore production rates were observed when the bacteria were in
cubated in Landy medium or in nitrate-nitrogen rather than in ammonium-nitr
ogen broth. Then the efficacy of the bacteria to promote plant health and g
rowth was evaluated. These studies were conducted in culture solution and i
n soil under different ecological factors. The results suggest that these b
acterial strains may produce substances that enhance plant growth and yield
on maize and sunflowers. However, the results also showed that in vitro an
tibiotic activity did not always correlate with disease reduction on maize
in greenhouse and field trials. Only in the case of the biological control
of Sclerotinia sclerotiorum on sunflowers in field trials, a satisfying eff
ectiveness was achieved. The results are discussed with regard to the gener
al effect of plant growth and health-promoting substances produced by Bacil
lus subtilis.