Soybean varieties viable in southern Indiana, resistant to root-kno...(le and animals. A major concern fo...)

A major concern for farmers is that soybeans, corn and watermelon are all susceptible to root-knot nematodes. Most farmers in southern Indiana plant crops in a soybean-corn-watermelon rotation. If the parasites infect the soybeans, then the organisms will be in the soil and can damage the subsequent crops planted in the same field.

"The availability of nematode-resistant varieties is important, not only for soybean production, but also for the whole rotation sequence because a resistant soybean crop will reduce the number of nematodes in the soil," Westphal said.

The study involved planting eight soybean strains in a commercial field near Vincennes, Ind. These were plant varieties that already were known to grow well in soil and weather similar to that found in southern Indiana. The field had a history of root-knot and soybean cyst nematode infestations. Westphal and his team also tested some of the same soybean lines in a field in which they introduced the nematodes and in a greenhouse where they used similar soil containing the root-knot nematodes.

Using plants known to be resistant to soybean cyst nematode, the researchers confirmed resistance to that nematode doesn't predict how resistant the plant will be to root-knot nematodes.

Although Indiana farmers previously were aware of the damage to their crops from soybean cyst nematode, it was only recently that they learned about root-knot infection of soybeans. They now know how to identify both nematodes and how these parasites damage crops.

Damage by plant-parasitic nematodes usually appears in patches in fields because where nematodes are introduced determines the infestation area. The type of soil and environmental conditions also play a role in the parasite's survival.

Both the soybean cyst and root-knot nematode feed on roots, robbing the plant of needed nutrients and water. The lemon-shaped soybean cyst nematode is easy t
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