Incidence of Anthonomus grandis increased by 500% in Brazil

Date:04-10-2024

The incidence of the Cotton Boll Weevil (Anthonomus grandis) increased by 500% in the current crop season in Brazil, especially in some producing areas such as the state of Mato Grosso. 

Cotton Boll Weevil causes considerable concern among cotton growers, as it is the crop’s most prevalent pest and has immense damage potential, capable of decimating up to 90% of a cotton crop.

According to Fábio Lemos, Crop Manager at FMC, late populations of Cotton Boll Weevil from the previous crop season have joined new groups that have been multiplying within soybeans, resulting in the high incidence of the pest. 

″The rains extended into last year, allowing cotton growers to load more cotton onto the plant, which in turn favors the presence of late boll weevil populations,″ he said. 

Additionally, there was a high level of leftover crop residue, as well as weed growth, in soybeans, he added, stating, ″Since it was a dry start to the year, controlling the insect was complicated.″

Another aggravating factor in combating this pest is its enormous reproductive capacity. ″The proliferation of this insect is very rapid and intense. Within the cotton cycle, there can be five or six generations of boll weevils,″ Lemos stressed. 

However, there is yet another factor adding to the concern, which is the fact that this season, the cotton growing area in Brazil increased by 13%, meaning there is more land for the pest to proliferate. All crops have been impacted, as the boll weevil's evolution is ongoing.

According to Lemos, FMC offers ″the Arc Farm Intelligence platform, which is another solution that greatly assists farmers, as it uses data from boll weevil trap collections to visualize the current status of the pest, whether on farms or through regional maps, providing information for localized management, entry routes, and predicting population and pest pressures a week in advance.″

Daily monitoring by Arc Farm Intelligence indicated a strong increase in boll weevil pressure in the state of Mato Grosso from June 2023 compared with the same period in 2022. The data showed a maximum of 21.6 weevils/trap/day between October and November 2023. In western Bahia, boll weevil pressure also experienced a significant increase from June 2023 compared to the same period in 2022, reaching a historic peak of 5.9 weevils/trap/day between September and November 2023.

The high boll weevil pressures recorded between the end of the 2022/2023 crop season and the start of the 2023/2024 crop season affirmed the importance of paying close attention to management throughout the cotton crop cycle. Currently, with the crop already sown in 100% of planting areas, the most appropriate way to mitigate the problem is through chemical insecticide management, both in terms of total area and borders, Lemos explained.

″At FMC, we have potent solutions that can effectively combat this pest, delivering excellent results. The insecticide, Premio Star (chlorantraniliprole + bifenthrin), protects against 50 pests in more than 50 crops, being the only product on the market that offers simultaneous control against the main pests and bugs,″ he further explained. 

″In addition, it provides cotton growers with strategic products that offer confidence, consistent results, and reliability, such as Malathion 1000 EC, Malathion UL, and Marshal Star,″ he said in conclusion.

(Editing by Leonardo Gottems, reporter for AgroPages)