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March 3, 2014

Safrinha Soybeans Increase Nematode Populations

Farmers in Brazil are opting to plant more safrinhasoybeans than never before even though agronomist have advised against planting a second crop of soybeans back-to-back due to an increase in diseases and pests such as nematodes. Nematodes are microscopic worms that feed on the soybean roots weakening the plant and reducing the yields. Once considered a minor problem in Mato Grosso, these pests have now spread across the entire soybean producing regions of the state.

Planting two crops of soybeans in a single year allows the nematode population to increase greatly and if this planting pattern is following for two or more years, extraordinary measures would probably be needed to bring the pest population back under control.

Controlling nematode populations is a tricky proposition due to the fact that the worms can develop new races that can overcome resistance that is bread into new soybean varieties. Using nematodes resistant soybean varieties over time allows new races of the worm to develop forcing farmers to change soybean varieties once again. Using corn or other crops for the safrinha planting helps to control the pest, but eliminate it.

A decline in corn prices coupled with strong soybean prices have encouraged some farmers to opt for a second crop of soybeans instead of corn. The research on nematode control in Mato Grosso is being conducted by the Fundacao Mato Grosso, which is an agricultural research institution.