Control Nematodes with Azolla

Dry and fresh azolla (Azolla pinnata) reduced populations of root-knot nematodes (Meloidogyne incognita) when incorporated into the soil of okra plants. Researchers in India found that when dry azolla was added at 1, 2, and 3 percent wet weight (w/w), the root knot index of the okra plants was significantly reduced. Wet azolla at 1 percent w/w had a similar effect. In treatments that received 4 to 5 percent w/w of dry azolla, the okra plants did not survive, probably due to phytotoxicity caused by the dry azolla. Plant height was significantly greater with 2 percent dry azolla.

Azolla is widely used as a soil amendment in Asia, as it provides a significant source of nitrogen. Used as a biofertilizer/green manure, azolla can also reduce nematode populations.

Thakar, N. A., et al. Azolla in management of root-knot nematodes in okra, Indian Journal of Nematology. 17:1, 1987.