Revista Brasileira De Herbicidas 2013; 12(3): 268-276
Alternative herbicides to control Raphanus raphanistrum L. resistant to metsulfuron methyl herbicide
The control of weeds in winter crops is done primarily with ALS-inhibitor herbicides. The intensive herbicide use in areas with wheat has provided selection pressure on R. raphanistrum resulting in biotypes resistant to these herbicides. The objective of this work was to determine the existence of cross and multiple resistance to ALS-inhibitors herbicides and alternatives to chemical control of this weed resistant to metsulfuron methyl. Treatments consisted of R. raphanistrum resistant (biotype R) and susceptible (biotypes S), with 12 herbicides: glyphosate, atrazine, bentazone, 2,4-D, sulfometuron methyl + chlorimuron ethyl, chlorimuron ethyl, cloransulam methyl, iodosulfuron methyl, nicossulfuron, imazethapyr, metsulfuron methyl, imazapic + imazapyr and a control without herbicide. It was applied the recommended dose of each herbicide at 3 to 4 true leaves stage. Control efficiency and reduction in dry matter of shoots were analyzed. The biotype S was susceptible to all herbicides used in the study. The biotype R has cross resistance to herbicides that belong to chemical group’s imidazolinones, sulfonylureas and triazolopyrimidines varying degree of sensitivity between these groups. The biotype R was not diagnosed with multiple resistance and glyphosate, bentazone, atrazine and 2,4-D shown to be effective in controlling biotype R and can be used for chemical management of R. raphanistrum.
274