Archive for the ‘Horton water-seeded test’ Category

Yesterday, County Agent Stuart Gauthier pulled core samples at the test site farmed by Alden Horton.  Alden wanted to really study the management of rice water weevils in a water-seeded system.  In this case, the only option for pesticide management is the use of pyrethroids.  The first step was to spend the time to scout properly before and after permanent flood for the presence of rice water weevil adults.  Stuart worked closely with Dr. Saichuk, myself and Alden to check the field on a regular basis – at least weekly, but often times more frequently.   It was a tough decision to decide on weevil management at this site. 

Permanent flood was applied on April 23, 2010. We scouted before flood, did not find weevils, so we decided to hold off on spraying.

On May 6, 2010, Stuart scouted the fields with Johnny and Alden.  At this time, the rice was at mid-tillering and rice water weevil adults (including mating pairs) were found in the field.  The population was sparse, but there are often many more that you don’t see.  We recommended an application of 2.0 fl oz of KarateZ.  Two small cuts that were separated by levees from the treated fields were left untreated for comparison.

We gathered 10 cores per field 4 weeks after permanent flood.  This is when you will see a peak in the population.  We processed the cores at the rice station yesterday – 10 cores per field – untreated and Karate treated.  In the untreated check, the average number of larvae per core was 4.8.  By comparison, the Karate treated field had a population of 0.9 larvae per core.  Much research has led us to conclude that each larvae can cause 0.5 to 1.5% yield loss.  Based on this estimate, we would predict that a yield loss from 2.4 to 7.2% may be experienced at this field site.  It appears that a treatment was called for at this location.

We’ll let you know how it looks as the season progresses.  We will probably have a stop here at the Vermilion Parish rice tour on July 6, 2010.

Our sincere thanks go to Mr. Alden Horton for cooperating in this demonstration test.

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On Friday we met with Stuart Gauthier and Alden Horton to scout for adult rice water weevils at the Vermilion Parish water-seeded test site.  This field is making good progress, and has an excellent stand, for the most part.  

We have a healthy water-seeded stand of rice.

  One of the high parts of the field had poor emergence due to a combination of dry soil and water mold. 

Standing in the thin stand of the field and looking to the nicely growing portion.

Some of the seeds germinated and then dried-out.

The un-emerged seeds, with the dark brown ring around them, were killed by water mold.

We visited the field to make a decision about rww insecticide applications.  We scouted ten sites in the field for the presence of rice water weevil adults and feeding scars.  We did not find any rww adults or feeding scars.  The decision at this time was to hold off on an insecticide application and scout again for adults or scarring before the final application of newpath on Friday.

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