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Isoflex™ Active Overview


Isoflex™ active is the trade name of Bixlozone, a new herbicide ingredient from the isoxazolidine family discovered and developed by the FMC research and development organization. It offers growers operational flexibility and lasting control of key grass weeds, including those with developed resistance to other herbicides, as well as some broadleaf weeds. Early season application timing enables growers to maximize productivity across multiple crop segments.

Isoflex™ active is not registered for sale or use. No offer for sale or use of this product is permitted prior to issuance of registration by the relevant local government regulatory agency.

Isoflex field day

Mode of Action

Isoflex™active, a new isoxazolidinone herbicide, inhibits susceptible plants from producing carotenoids – pigments that are critical to protecting photosynthetic processes and ensure normal plant growth and development. This effect, which is often referred to as bleaching, stops the photosynthesis in target weeds leading to their death. Studies of tolerant crops show that these symptoms are transient with no effect on the vigor and yield. In addition to inhibiting the production of carotenoids, Isoflex™ active slows down the production of key amino acids in susceptible plants. It is also able to control weeds through the combination of disruption of light reactions as well as protein turnover and degradation.

Isoflex active combatting annual ryegrass

Weed Control

Isoflex™ active provides a new and unique selective residual weed control solution in a wide range of crops including, cereals, corn, legumes, rapeseed, and sugarcane, and will offer a new mode of action herbicide solution for many of these crops. Isoflex™ active provides both systemic and contact activity, with residual control, and will be able to be applied pre-emergence, early post-emergence or incorporated by sowing, across a wide range of agronomic environments. By inhibiting carotenoid production, Isoflex™ active controls problem grass weeds, including ryegrass, and some key broadleaf weeds. In weed control programs, it will be a valuable tool to help improve blackgrass control.

A sampling of weeds that Isoflex active has been shown to control

Resistance Management

Weed resistance is a global phenomenon, but the specific challenges vary at the local level, and so should the weed management tactics. When planning a weed control program, FMC recommends selecting products from different site of action (SOA) groups to control the same weed either in successive applications or in mixtures. Reference the HRAC, AUS, and WSSA classifications of herbicides to plan the appropriate herbicide mixtures or rotations within an integrated weed management system. Isoflex™ active is a new active ingredient that is proposed to be classified as an HRAC Group 13 and AUS Group Q herbicide. As only the second active substance belonging to the isoxazolidinone family, Isoflex™ active will offer a new rotational product and a tool for resistance management, especially in cereals. Isoflex™ active will also be a complementary mixing partner for broadleaf herbicides as it can extend the utility of existing products by expanding the spectrum of weeds controlled. While herbicides are one tool for weed control, FMC also supports integrated weed management programs that utilize a wide variety of weed control practices to ensure that herbicides remain as sustainable tools.

Isoflex active defending against grasses in soybeans

Application Flexibility

Weeds reduce yields by competing for space, light, water, and nutrients, weakening crop stand, and by reducing harvest efficiency. Effective weed management involves developing a sound herbicide strategy to control weeds at crucial points throughout the season. Pre-emergence herbicides are important for controlling weeds after the seeds germinate, but before they emerge from the soil. Pre-emergent herbicides are key to reducing weed pressure and removing competition early in the growing season. Isoflex™ active provides both systemic and contact activity, with residual control. The herbicide can be applied pre-emergence or early post-emergence, across a wide range of agronomic environments.

Plant uptake study - foliar & roots vs foliar

Registration Status

This innovative herbicide is registered in Australia for cereals and rapeseed under the Overwatch® herbicide brand. Visit the Overwatch® herbicide website for more information. Registration is pending in Argentina and planned in Europe, Latin America and Asia.

Isoflex field day