Embrapa: New soybean varieties combine herbicide tolerance and resistance to the crop's main pests

Two new soybean cultivars with the innovative technology Intacta2/Xtend^® (I2X) are now available to producers. 

These cultivars combine tolerance to the herbicides glyphosate and dicamba with resistance to the main caterpillars and diseases of soybeans.   

Developed in partnership between Embrapa and Fundação Meridional, BRS 2361 I2X and BRS 2058 I2X have great potential for impact in the 2024/2025 harvest since they still have a high production ceiling, higher than that of the varieties found on the market.

According to Carlos Lásaro Melo, a researcher at Embrapa Soja (PR), BRS 2361 I2X is a cultivar with an innovative profile that, in evaluation tests, produced over 5,000 kilos per hectare (kg/ha), surpassing several cultivars currently available on the market. ″In addition, it is resistant to the main diseases that affect soybeans: stem canker, Phytophthora root rot, bacterial pustule, and moderate resistance to frogeye spot,″ he highlighted.

Melo emphasized that BRS 2361 I2X belongs to maturity group 6.1, with an average cycle of 120 days in the environments tested, and has greater production potential at altitudes above 600 meters in Paraná and São Paulo (REC 201). ″Another highlight is that it allows early sowing, making it possible to sow second-crop corn in the best planting 'window' in the region where the cultivar is indicated,″ he added.

The other launch is BRS 2058 I2X, which is widely adaptable to the Southern Region, also with high productivity ceilings, surpassing the main competitors in the market. ″This cultivar has excellent yields, especially at altitudes above 650 meters″, highlighted researcher Antonio Pipolo. It is a cultivar of maturity group 5.8, with an average cycle of 125 days, and is recommended for Rio Grande do Sul (REC 102 and 103), Santa Catarina (REC 102 and 103), Paraná (REC 102 and 103) and São Paulo (REC 103).

Regarding health, it is resistant to the central soybean diseases – stem canker, bacterial pustule and Phytophthora root rot – and moderately resistant to frogeye leaf spot and the root-knot nematode M. javanic a. ″Resistance to Phytophthora is a major differentiator for BRS 2058 I2X, as it is a disease that has been causing many plant deaths in susceptible soybean cultivars in recent harvests, especially in colder regions, where it is indicated and has high production potential,″ Pipolo said.

The executive manager of the Meridional Foundation, Ralf Udo Dengler, emphasized that the launch of these two cultivars with the I2X platform is a vital milestone in the partnership with Embrapa, which recently completed 25 years. "We are planning a significant seed production in the 2024-2025 harvest, and thus, we will be able to offer a quantity that is adequate to the market demands. We have high expectations, as BRS 2058 I2X and BRS 2361 I2X have already demonstrated their great production potential in trials and demonstration areas. Producers will certainly generate a great demand for seeds, and we will be ready to serve them," Dengler highlighted.

Caterpillar management

The Intacta2/Xtend^® (I2X) technology present in the launches combines three proteins (Cry1A.105, Cry2Ab2, and Cry1Ac), which increase protection against six species of caterpillars that affect soybean crops:  Helicoverpa armigera,  Spodoptera homicides, false looper (Chrysodeixis includens), soybean caterpillar (Anticarsia gemmatalis), apple caterpillar (Chloridea virescens) and axil borer (Crocidosema aporema). Researcher  Daniel Sosa Gómez explained that the pyramiding of three proteins reduces the probability of resistance breaking. ″However, a fundamental aspect of avoiding the selection of resistant caterpillar populations in crops with this technology is the planting of structured refuge areas,″ he observed.

The current recommendation for refuge areas for soybean crops is that at least 20% of the area should be planted with technology other than I2X. According to the researcher, this is a preventive measure that consists of growing part of the crop with other non-Bt soybean options (without  Bacillus thuringiensis  (Bt) toxins) at a maximum distance of 800 meters from crops with I2X technology. ″The adoption of the refuge area allows for the random mating of moths from areas with I2X technology and refuge areas, favoring the maintenance of susceptible populations and delaying the selection of resistant populations,″ he said.

Sosa Gómez also emphasized that pest management in crops with I2X technology follows the premises of Integrated Pest Management (IPM), such as monitoring and controling pests when they reach the action level and prioritizing the use of more selective insecticides.

I2X in weed management

Soybean cultivars with I2X technology are tolerant to the herbicides glyphosate and dicamba, which are effective in managing broadleaf weeds, such as buva, caruru, morning glory, and black beggarticks, among others. ″Dicamba is a herbicide registered only for application during the pre-sowing of soybeans. The information contained in the package insert must be followed, as use in disagreement with the technical guidelines may cause problems in crops that are not targeted for the application of the herbicide,″ warned researcher  Fernando Adegas.

Adegas stated that the integration between management practices involves chemical control, mainly the rotation of herbicide action mechanisms, but also alternative practices such as crop rotation, the use of cover crops in the soybean off-season to generate good straw, the cleaning of agricultural machinery and implements, and the use of quality seeds free of resistant weeds to prevent the reproduction of these species.