Response of cogongrass (Imperatacylindrica) to the various doses of glyphosate in sugarcane crop of southern Iran

AYNEHBAND AMIR | FَARKHONDEH ESKANDARI | Yousef Filizadeh | KERAMAT BATOOL

---

URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=159345
Date :  2021/12/15
Publish in :    Indian Journal of Agronomy


Keywords :: Cogon grass, Rhizome viability, Glyphosate, Sugarcane

Abstract :

---

With the objective of effective management of cogongrass. An experiment was conducted to examine the physiological responses of row and furrow cogon grass to (Imperata Cylindrica L. Beauv) the different doses of glyphosate rates (0, 0.92, 1.84, 2.76, and 3.68 kg a.i/ha) during sugarcane crop spring season. The data revealed that stomatal conductance was decreased more than 50 at all the doses of glyphosate compared with control. Total chlorophyll and carotenoid contents were decreased, with a maximum of 94 and 28 at the doses of 1.84 to 3.68 kg a.i./ha respectively. There was also a significant increase in leaf shikimate content (up to 96 in the furrow plants), antioxidant activity (up to 37 in the row plants), and cell leakage (up to 54 in the row plants) at the 3 highest doses of glyphosate. Increase in antioxidant activity was not significant in the furrow seedlings, probably due to the previous stress of higher soil moisture imposed in the form of flood irrigation. Shikimate accumulation and physiological responses indicated that, cogon grass was sensitive to glyphosate at the doses up to 1.84 kg a.i/ ha. The rhizome viability in the treated plants was more than 50 than the control plants, and a substantial regrowth was recorded 5 months after of the application of glyphosate. The results indicated that the failure to control cogon grass might be due to the lack of glyphosate accumulation in its rhizomes during the spring season as well as its relative tolerance to the repeated glyphosate applications over consecutive years in the sugarcane crop, however, this needs further investigation to confirm the results.