How to Control Root Knot Nematode

How to Control Root Knot Nematode


Soybean is one of the most important grain
crops in the United States. In the southern US many farmers grow soybean on
land previously cropped only to cotton. Many cotton-associated pathogens impact
soybean–in particular, the southern root knot nematode. This nematode can inflict severe damage to
soybean resulting in significant yield loss. Control methods are limited. These
strategies include crop rotation: planting crops that are
not host to root knot. However, southern root knot nematode has a
broad host range, limiting choices. Nematode-resistant soybean varieties. However, the number of high-yield-
producing resistant varieties are limited. Nematicide application, such as the pre-plant fumigant Telone II, or seed-applied nematicides. Seed treatments can provide short periods of
production if nematode pressure is low, but are not as effective as Telone. However, Telone supply is
limited, and application costs are high. The plant pathologists from the mid-southern US are focused on sustainable nematode control. For example, if nematicide applications are limited to specific areas where damage is severe, then the volume of nematicides used can be reduced. This is possible because nematode populations are dependent on soil texture, which is quite variable in many fields. The southern root knot nematode prefers coarse, sandy soils, which typically had a history of cotton production. A study was conducted in the
southern US comparing strips of soybean either non-treated or Telone treated,
with or without a seed applied nematicide. Using two different nematicides enabled
the team to determine their relative effectiveness. Electrical conductivity was used to
create soil texture maps. Electrical conductivity primarily
measures soil salt concentrations, which are strongly related to soil texture. The finer the soil texture, the greater the salt concentration, resulting in greater electrical conductivity. Soil samples collected from each field help determine the abundance of specific nematodes present. Yield maps were created to establish the relationship between yield, soil texture, nematode population, and nematicide treatment. Results indicated that in areas
where the soil textures favored root knot nematodes, Telone treatments
significantly improved soybean yield. However, nematicide application did not affect yield where soil type did not favor the nematode. Therefore, site-specific applications of Telone can be used to control root knot nematode and maintain high soybean yield.

Leave a Reply

Your email address will not be published. Required fields are marked *