Herbicides Affect the Chlorophyll Contents in Artichoke Leaves (Cynara cardunculus L.).

Artichoke leaves are a rich source of polyphenols that are accredited to the nutritional and pharmacological belongings. Caffeoylquinic acids, flavonoids and sesquiterpene lactones are some of the important polyphenols in artichoke leaves.

A research project for studying the impact of selected post-emergence herbicides on chlorophyll contents of artichoke leaves was conducted at experimental research area of the Department of Agronomy, Justus-Liebig University, Giessen, Germany during the year 2008.

The results of the experimental study suggested that Pyridate, Aclonifen and Clomazone applied after the germination of artichoke resulted in significant leaf yield reduction during both growth phases. A closer look of the chlorophyll fluorescence data showed a stress to the artichoke was applied by the application of Pyridate which was visible by the reduced chlorophyll fluorescence value in this treatment. Similar negative effects were also observed in case of post emergence application of Phenmedipham, Aclonifen and Clomazone. Negative impact of the post emergence application of these herbicides appeared at 1 day after application and continued till 1 week after application. These symptoms of the stress considered as chlorophyll fluorescence disappeared at 4 weeks after the herbicide application. Artichoke leaves may have recovered against these adverse effects of herbicides by regenerating and developing new leaves.

Experimental study led to the following conclusions;

• Chlorophyll fluorescence measurement can be used to detect the herbicide stress in artichoke leaves under field conditions.
• Artichoke can recover this stress along with the development stages depending on the severity of herbicide stress and prevailing environmental conditions.