ARS | Publication request: Effect of Meloidogyne incognita infection on leaching of nitrogen in cotton

Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: June 20, 2007
Publication Date: July 5, 2007
Citation: Timper, P., Strickland, T.C., Hubbard, R.K. 2007. Effect of Meloidogyne incognita infection on leaching of nitrogen in cotton [abstract]. Journal of Nematology. 39:69.

Technical Abstract: Root damage from parasitism by nematodes reduces the ability of the plant to take up water and nutrients. Recently, parasitism of cotton by Rotylenchus reniformis was shown to increase mineralization of nitrogen (N). We hypothesized that, because of increased mineralization and reduced uptake, more N would leach from the root zone of cotton parasitized by Meloidogyne incognita than from non-parasitized cotton. We constructed lysimeters out of 23-liter plastic buckets to collect leachate from different nematode treatments. The lysimeters were filled with 18 liters of field-collected loamy sand and planted with a single cotton seed. The soil was fertilized with 10-10-10 (NPK) at planting and ammonium nitrate 5 weeks later. The nematode treatments were zero, 8000, and 20000 M. incognita eggs per plant. The nematodes were inoculated in a split application with ¼ applied at planting and ¾ applied 3 weeks later. When roots were examined 15 weeks after planting, root gall indices (0 to 10 scale) were 0, 2.6, and 7.6 for the three nematode treatments. Nematodes reduced plant top weight but not root weight. There was an increase in the amount of leachate with increasing nematode inoculum which was probably due to reduced evapotranspiration by nematode-infected plants. However, nematodes did not affect the total amount of N leached from the root zone.