Reglone (Syngenta)

Reglone Herbicide is a non-selective burndown and contact herbicide containing 3.73 lb salt per gal. as diquat dibromide monohydrate, slightly less than Gramoxone 3.0. The Reglone solution quickly kills weeds by interfering with the process of photosynthesis, causing rapid desiccation of foliage for pre-harvest weed control or crop desiccation.

Mode of action

Light and green leaf tissue are essential components to the activity of Reglone. The herbicide acts as a catalyst in the chloroplasts of plant cells, interfering with the process of photosynthesis at Photosystem I. The active ingredient diquat, diverts electron flow causing the production of peroxides and free electrons. These superoxides attack proteins and cell membranes, ultimately leading to desiccation of plant tissue.

Following the application of Reglone, penetration through the leaf surface occurs almost immediately and the physiological action of diquat takes place within a matter of minutes.

Due to the requirement of light for photosynthesis, Reglone is inactive in darkness. Despite this, the herbicide may continue limited diffusion into neighbouring cells in the absence of light. For this reason, Reglone often provides a more effective kill when applied at dusk or on cloudy, overcast days, as the cell desiccation reaction is delayed until the compound has moved more evenly throughout the leaf.

Reglone binds quickly and strongly to soil and organic material and is no longer biologically active once absorbed. The herbicide therefore poses a negligible risk to leaching and is readily degraded by soil microbes to natural products including water, carbon dioxide and ammonia.