Highlights of the Rice Research Station 2014 Field Day - Part II

Unmanned aerial vehicle (UAV) at field day.

The 105th LSU AgCenter Rice Research Station Field Day was held on June 25. In spite of the threat of inclement weather, more than 400 people turned out for the event. The threat of rain caused the cancellation of the field tours, so the field tour speakers made their presentations indoors to the entire group instead. Tour speakers included scientists from the Rice Station, Dean Lee Research Station, Baton Rouge campus, University of Arkansas and Mississippi State University. Last month we discussed presentations on rice breeding, weed control and insect control. This month we will focus on disease control, hybrid breeding, agronomy and the use of unmanned aerial vehicles (UAVs) in agriculture

Dr. Don Groth discussed his research program, including efforts to increase levels of disease resistance in future varieties. The major diseases he works with are sheath blight, blast, Cercospora and bacterial panicle blight. His screening programs include current varieties, potential releases, the Uniform Regional Rice Nursery, breeding lines in the preliminary yield (PY), and special populations of interest, such as Clearfield lines, marker populations and genetic studies.

In the past several years, screening efforts have been increased significantly by incorporating earlier generation lines into the program. The result is a significant increase in the number of rows being screened for multiple diseases, which included more than 15,000 this year. A major accomplishment of these efforts has been the decrease in sheath blight susceptibility levels and improved tolerance to sheath blight in recent varieties. Older varieties typically lost 25 percent to 50 percent yield to sheath blight under very severe conditions. Newer varieties have shown good tolerance, losing only 4 percent to 17 percent yield under the same conditions.

Dr. Groth also discussed the sheath blight pathogens that are resistant to the fungicides azoxystrobin and trifloxystrobin. These two fungicides have been widely used in Louisiana rice production in recent years, and resistance to these fungicides was documented in the Mowata area in recent years. It is apparent that the area where resistance is found continues to spread. Fortunately, a new fungicide, fluxapyroxad, which will provide control where the resistant pathogen is found, has been available for use in the past few years under an emergency exemption and now has a federal label for 2014.

Dr. Clayton Hollier discussed his research to better understand Cercospora and thus be better prepared to minimize the disease’s impact. Some of the major findings of his work include:

  • The initial inoculum (the fungus that starts the disease development process) comes from infected crop residues from previous crops and from nearby weeds.
  • The micro-environmental conditions within the lower canopy must be at least 82 F with at least 15 hours of leaf wetness to germinate Cercospora spores and establish the disease.
  • Nitrogen deficient rice is more susceptible to Cercospora development.
  • At present the only fungicide that provides adequate management of Cercospora on rice is propiconazole.
  • Rice planting date influences development of Cercospora. If planting is in March to mid-April and if propiconazole is applied for Cercospora, the application time should be at early to late boot. If the planting date is later than mid-April, then the Cercospora fungicide application should be at panicle initiation to early boot, due to the buildup of inoculum over time in later planted rice.

 Dr. Jim Oard discussed the Rice Station’s hybrid breeding program. He stated that several hybrids in the program continue to show excellent performance. The hybrids LAH10, LAH25 and LAH28 have consistently produced high yield potential with good milling performance over the past two years in multilocation trials. These hybrids also display excellent grain quality, which is a major emphasis of the program. The overall aim of this program is to provide a superior rice hybrid to the industry as soon as possible.

Dr. Dustin Harrell discussed reducing nitrogen volatilization losses in rice production. When it will take more than five days to apply the permanent flood to an entire field after applying preflood nitrogen (preferably to a dry soil), a urease inhibitor containing the active ingredient N-(n-butyl) thiophosphoric triamide, or NBPT, is recommended. The urease inhibitor slows down the breakdown of urea to the ammonium-N form, which is available to plants. Because it temporarily delays the breakdown of urea, it also temporarily delays the potential for ammonia volatilization losses.

Dr. Randy Price and Mr. Charles Malveaux demonstrated the use of UAV systems in agriculture. UAVs have been developed to allow farmers and producers to spot and diagnose field problems. These systems will be especially useful in the rice industry because fields are routinely flooded and access is limited. UAVs will also be useful in rice research efforts. One area being explored is the use of a UAV to facilitate the movement of pollen from a restorer line of rice plants to pollenate a male sterile line in hybrid seed production.

The 2015 Rice Research Station Field Day is scheduled for Wednesday, July 1. Mark your calendar and make plans to attend.

Permission granted August 22, 2014 by B. Leonards (LA Farm & Ranch) to republish article on www.lsuagcenter.com

8/22/2014 6:32:27 PM
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