Investigation of the Gliphosate Impact on the Leaf Gas Exchange and the Photosynthetic Pigments Content in Some Perennial Weeds

I. ZHELYAZKOV, Z. ZLATEV and Sh. KALINOVA
Agrarian University, BG - 4000 Plovdiv, Bulgaria

Abstract

ZHELYAZKOV, I., Z. ZLATEV and Sh. KALINOVA, 2004. Investigation of the gliphosate impact on the leaf gas exchange and the photosynthetic pigments content in some perennial weeds. Bulg. J. Agric. Sci., 10: 439-446

The field tests were carried out at the Agrarian University - Plovdiv, Bulgaria in the period 1999 - 2001. They included four variants with different doses of gliphosate, at different phases of the genetically modified maize. According to the results we got the following conclusions: Gliphosate (Roundup Bioforce) in doses 1, 2, and 4 l/ha provokes material changes in the leaf gas exchange of Cynodon dactylon Pers., Sorghum halepensis Brot., Cirsium arvense Scop. and Convolvulus arvensis L. even in the 24th hour after the treatment. The carotinoids content in the 96th hour following treatment with Roundup Bioforce in doses 2 and 4 l/ha increases in Cynodon dactylon Pers., Sorghum halepensis Brot., and Convolvulus arvensis L. and reduces in Cirsium arvense Scop.

Key words: maize, gliphosate, leaf gas exchange, photosynthetic pigments, perennial weeds