Naslov
Herbicide resistant weeds and search for biocontrol agent in Yugoslavia

Autori
Šovljanski, Radmila ; Arsenović, Marija ; Ostojić, Zvonimir ; Klokočar Šmit, Zlata ; Janjić, Vaskrsije

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), stručni

Izvornik
Herbicide-resistant weeds and alternative control methods - Experts Group Meeting / - Tølløse : Commission of the European communities, 1989, 153-160

Skup
Herbicide-resistant weeds and alternative control methods

Mjesto i datum
Tølløse, Danska, 15.11.1988. - 17.11.1988

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
weeds, herbicides, resistante

Sažetak
In the area where the crop rotation is poor or noncropped land where the high dosages of triazine herbicides are permanently applied, the problem of residues is combined with the threat of resistant biotypes of weed appearance. The chemical analyses of soil samples from canal slopes during four years revealed the long persistance and high level of residues. This coincided with the changes in the plant association composition. The population densities of some weed species such as Amaranthus retroflexus, Erigeron canadensis and Chenopodium spp. increased. Under the controlled conditions, biotest in the chernozem soil with different concentration of atrazin was conducted. The seed of A. retroflexus collected from the sites continuously treated with atrazine and from untreated plots was germinated. The decrease in biomass net weight of young plants derived from the seed of the plants suspected of resistance in the nature, coresponded with the increase of the atrazine content in the soil. At the same time, the seed from the succeptible biotype did not form the biomass in soil with atrazine dosage as low as 0, 5 kg/ha. The plants derived from seed from the same bulks produced the plant which differently responded to the atrazine concentration of 20 mg/l. The total inhibition of photosynthesis occured in the succeptible, while only negligible, in resistant biotypes. Because of the increase in frequency of the biotypes of different weed specied resistant to widely used herbicides, the search for possible biocontrol agent was undertaken. Downy mildew (Peronospora farinosa) was registered on Chenopodium album and C. hybridum. The white rust (Albugo cliti) did appeared very often, sometime in epiphytotic degree. One Alternaria sp. isolate was obtained from spotred leves of Amaranthus retroflexus and its pathogenicity confirmed in glasshouse experiments. One isolate of Drechslera sp. and one of Alternaria sp. has been obtained from the seeds of Erigeron canadensis. Thed pathogenicity of both was proved in young seedlings. Xanthum strumarium, was also observed on canal sites. Puccinia xanthii appeared regularly on leaves, but some more promicing Fusarium species were obtained from the roots of wilted plants on several sites.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA