Effective control of Southern root knot nematode looks promising with the use of GPS-controlled, variable-rate applications of soil fumigants, according to University of Arizona researchers, as reported by Western Farm Press.
Field trials conducted from 2006 to 2010 tabulated information gathered by global positioning systems and variable rate technology, including the electrical conductivity-based Veris 3100 and EM38 sensors for on-the-go soil mapping, plus harvest yield mapping data.
This technology illustrates that nematicide applications can be applied sparingly in some cases while maintaining good nematode control and trimming chemical costs.
The grower cooperator field trials included six studies with the nematicide Telone II applied at pre-plant in cotton and corn in central and southwestern Arizona conducted by University of Arizona (UA) researchers Randy Norton, Tim Hatch, Mike McClure, and Pedro Andrade.
Norton, UA regional extension cotton specialist based in Safford, shared the findings during the 71st annual Cotton Disease Council meeting at the 2011 Beltwide Cotton Conferences in Atlanta, Ga., in January.
Norton labeled the RKN as the No. 1 nematode species threat in Arizona. The microscopic roundworm damages crops by attacking the young tap and secondary roots which stimulates the production of galls. Galls interfere with the ability of the roots to absorb water and nutrients, and allow other disease-producing organisms to enter the plant.
Arizona hotspots for RKNs include the Coolidge, Casa Grande, Florence, and Buckeye areas in central Arizona and the Bonita area in the Sulphur Springs Valley in southeastern Arizona.
In cotton, the RKN is responsible for a 5 percent lint yield reduction on average across the Cotton Belt, Norton says. Five gallons is the standard Telone II application rate in Arizona to maintain cotton yields in RKN-infected fields.