Applied non-destructive methods for determination resistance level in common lambsqurters (Chenopodium album L.) to atrazine

The aim of our investigation was to establish the degree of atrazine resistance in plants of Chenopodium album L. population from Serbia and resistance population from Great Britain. Seeds used in experiments were collected from the corn grown areas treated with atrazine for over ten consecutive years (Surčin and Veliki Crljeni), while the control seeds were collected from untreated areas nearby Belgrade (Belgrade). As a referent population resistant seeds of Chenopodium album L. from Great Britain were used. Plants in fully emerged third leves, from all population, were sprayed with different doses (2, 4 and 8 kg ha-1) of atrazine (Gesaprim, 90% a.i. atrazine). As a non destructive methods we used SPAD-meter for measuring chlorophyll content and fluorometer for chlorophyll a fluorescence which is expressed as ratio between variable (Fv) and maximal (Fm) chlorophyll fluorescence. Both parameters were measured at the same leaf before and 1, 2, 3, 4 and 5 days after atrazine treatments. Results shown that the most sensitive method is by using method of chlorophyll fluorescence. SPAD-meter is not adequate for distinguishing triazine resistant and susceptible plants. In populations of Chenopodium album L.- collected from Serbia (Veliki Crljeni, Surcin and Belgrade) atrazine resistance is not confirmed.