Gowan’s rice herbicide ‘Avanza’ obtains exceptional authorization in Spain

Farmers in the autonomous Spanish regions of Extremadura and Andalusia will have at their disposal, from April 25 to July 24, Avanza^®, a new Gowan herbicide effective against many weeds that affect rice, including those that have become resistant to most herbicides commonly used on rice fields.

The efficacy of Avanza^®, which is based on benzobicyclon, an inhibitor of the HPPD enzyme, was evaluated in several trials in greenhouses and fields conducted between 2013 and 2020 involving pre-seeding, pre-emergence and early post-emergence applications. Field applications carried out in submerged rice fields showed a high level of control of Leptochloa spp., Heteranthera spp. and Cyperus difformis, as well as a secondary activity against Echinochloa spp.

Benzobicyclon is a new herbicidal active substance discovered by SDS Biotech and developed in collaboration with Gowan Group. The herbicide, in various formulations and mixtures, is already registered in Japan, South Korea, Taiwan, the United States and Colombia. It has also obtained exceptional use approval in Italy, Greece and Portugal.

Benzobicyclon belongs to the chemical family, bicyclooctane, and has an excellent toxicological and environmental profile. Due to its mechanism of action in inhibiting the 4-HPPD enzyme, it is classified by the HRAC (Herbicide Resistance Action Committee) under Group F2, and in parallel by the WSSA (Weed Science Society of America) under Group 27.

Avanza^® should be applied on flooded soil at a dose of 0.75 l/ha with a volume of broth between 200 and 300 l/ha. It is important to keep the plot flooded with a water level of 6cm to 10 cm and without water movements for at least seven days. Benzobicyclon becomes active once it comes into contact with water, and it is absorbed through the roots and young stems. The first symptoms include the whitening of cotyledons and young leaves a few days after treatment. As the plant continues to be contact with Avanza^®, the bleaching turns into necrosis and, finally, the destruction of the treated individual plant.

Various studies have shown that benzobicyclon, applied during preemergence, remains localized in the first soil layer. These studies also showed that persistence is prolonged over time, even beyond ten weeks.

Avanza^® is also an ideal solution for resistance management, since it is effective against weeds resistant to herbicides traditionally used in rice, through its mechanism of action on the ALS and ACCase enzymes. “Considering the complexity in the weed management of rice cultivation, as well as the scarce availability of authorized herbicides and the results of trials with benzobicyclon compared to several references, Avanza^® can be a new tool for rice producers,” said Marco Vignini, Marketing Manager of Gowan Spain.