New bean variety BRS Guatã promises to control nematodes in Brazil

The BRS Guatã, a new variety of cowpea, has been introduced to the Brazilian market, capable of inhibiting nematode reproduction in the soil. 

Additionally, the launch contributes to the recovery of degraded pastures and supports cattle feeding during the dry season, according to Embrapa Pecuária Sudeste, the developer.

Research has revealed that BRS Guatã has the potential to control four nematodes of significant occurrence, primarily in soybeans and sugarcane, namely Pratylenchus brachyurus, P. zeae, Meloidogyne javanica, and M. incognita. These parasites are capable of causing annual losses of R$35 billion to national agriculture, according to the Brazilian Society of Nematology (SBN).

"It took years of work to develop this cultivar. The potential to control nematodes is its main characteristic, due to the damage they cause to national agriculture. In addition to soybeans and sugarcane, they also parasitize bean crops," explains researcher Rodolfo Godoy, who is responsible for developing this material.

According to him, the BRS Guatã cowpea is an effective option for rural producers in controlling these parasites, as they do not multiply in this variety. Furthermore, the legume has great potential to contribute to the sustainability of livestock, promoting soil health, reducing costs with pesticides and fertilizers, and increasing animal productivity.

For animal feed, cowpea is a legume rich in protein, with values around 15%, and has a high capacity to associate with bacteria that perform nitrogen fixation in the soil. BRS Guatã is presented as a low-cost alternative for supplementing cattle volumes during the dry season. The use of this purpose allows for increasing the stocking rate per hectare and reducing forage scarcity during the dry period, resulting in greater weight gain for the animals.

Additionally, according to researcher Patrícia Anchão Oliveira, the new cultivar has demonstrated itself to be a viable alternative for cover crop production and green manure in rotation with other crops. In tests, it produced three tons of dry matter per hectare in dry conditions and 3.3 tons per hectare with irrigation. This small difference highlights the high tolerance of this legume to water deficit.

BRS Guatã has a shorter vegetative cycle compared to other cowpea cultivars, such as BRS Mandarim. Embrapa researcher Frederico de Pina Matta notes that this characteristic anticipates the availability of forage for animals, as their consumption increases during flowering. It flowers about 30 days before BRS Mandarim and has good establishment speed in the field.

Another interesting feature of Guatã, according to Matta, is the plant's height and structure. The cultivar has an intermediate height with thinner and more flexible stems, which facilitates cultural treatments compared to the BRS Mandarim cowpea.

When integrated into soybean culture, the variety is not a host for Phakopsora pachyrhizi Syd. & P. Syd, the agent of soybean rust. It also has moderate resistance to Macrophomina phaseolina, the fungus that causes stem rot.

Some other characteristics can be associated with BRS Guatã and impact the productivity of pastures or annual crops, such as the high amount of dry matter. From green manure, BRS Guatã enables the supply of approximately 80 to 120 kg of nitrogen per hectare, facilitating the cycling of essential nutrients for the soil. 

The decomposition of biomass releases crucial nutrients for the soil, including nitrogen, phosphorus, potassium, and micronutrients, which benefit the subsequent crop. Additionally, it can serve as an alternative for protection and shading plants for the implementation of other crops, such as coffee and fruit trees.

With all these benefits, BRS Guatã represents a significant advance for Brazilian agriculture, offering an integrated solution for pest management, food production, and the sustainability of production systems.

(Editing by Leonardo Gottems, reporter for AgroPages)