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Effect of post-emergence herbicides on stress indicators in quinoa
Merino, Jorge; Pedreros, Alberto; Fischer, Susana & López, María D.
Abstract
The impact of herbicide application on the accumulation of secondary metabolites and photosynthesis as stress indicators
in the quinoa (Chenopodium quinoa Willd.) crop is unknown. The objective of the present study was to evaluate the
effect of two post-emergence herbicides on production, total polyphenol content, and chlorophyll fluorescence in
quinoa. The experiments were conducted for two consecutive seasons using a completely randomized block design with
seven treatments, including two herbicides and three commercial product rates, as well as a control without herbicide
application. Production parameters, yield components, and stress indicators were evaluated. Yield was affected (P <
0.05) by herbicide application in some treatments; control and treatment with only one bentazon application varied from
1851.23 to 1235.03 kg ha-1, respectively. Yield affected the number of grains per plant (P < 0.05); control and treatment
with only one bentazon application decreased yield from 3984.60 to 2040.94 kg ha-1, respectively. Total polyphenol
content and percentage of germination in quinoa grains were not affected by stress caused by herbicide application (P >
0.05). The herbicide fomesafen did not affect the maximum quantum yield, while the herbicide bentazon had a significant
effect (P < 0.05) during the application. Three sequential applications of bentazon and fomesafen in the absence of weeds
were sufficient to achieve a yield that was equal (P > 0.05) to the control.
Keywords
Chemical weed control in quinoa; Chenopodium quinoa; chlorophyll fluorescence; stress indicators; total polyphenols.
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