Mechanism of Intraspecific Selectivity of Cabbage to Nitrofen
1971; Cambridge University Press; Volume: 19; Issue: 6 Linguagem: Inglês
10.1017/s0043174500050955
ISSN1550-2759
AutoresJosé Francisco Martins Pereira, Walter E. Splittstoesser, H. J. Hopen,
Tópico(s)Pesticide and Herbicide Environmental Studies
ResumoThe plant characteristics which makes ‘Hybelle’ cabbage ( Brassica oleracea var. capitata L.) relatively tolerant while ‘Rio Verde’ is susceptible to the toxic action of 2,4-dichlorophenyl- p -nitrophenyl ether (nitrofen) were investigated. No differences between ‘Hybelle’ and ‘Rio Verde’ were found in growth rates, light or dark germination, or stomata density. Little xylem or phloem translocation of nitrofen- 14 C occurred. Disruption and removal of the cuticle of ‘Hybelle’ increased its susceptibility to nitrofen while ‘Rio Verde’ with more than normal wax deposition was tolerant. Plants with less cuticle were more susceptible, regardless of cultivar. ‘Hybelle’ had more wax per unit surface than ‘Rio Verde’ and wax deposition increased with leaf age. Both cultivars were equally tolerant to nitrofen when 6 weeks old. ‘Rio Verde’ leaves absorbed nitrofen- 14 C twice as fast as ‘Hybelle’ leaves. The results show that the mechanism of intraspecific selectivity of cabbage to nitrofen is dependent on the amount of cuticular wax on the leaves at the time of nitrofen application.
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