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Louisiana Rice: Harvest Decisions And A Potential Storm

Ernst Undesser
By Dustin Harrell and Michael Deliberto, Louisiana State University June 19, 2017

Louisiana Rice: Harvest Decisions And A Potential Storm

The weather in southwest Louisiana has improved over the past week. It is amazing what a few days of sunshine can do for the rice crop. Unfortunately, it looks like more rain incoming to the area this week. There is a good chance that a tropical (or subtropical) depression or storm will form in the Gulf of Mexico later this week. NOAA has named the potential system as Invest 93L and it currently sits near the Yucatan Peninsula.

It is still too early to know how big or small the system will be or exactly where it will track. However, one thing is certain, it will bring rainfall into the Gulf Coast. Heavy rains are expected to be associated with this system as far west as eastern Texas.

Some of the early rice in the southern part of the state is nearing the soft dough stage of development. Producers who are considering ratooning this rice and who are applying aninsecticide application for stink bugs may want to consider adding 4 grams of gibberellic acid to the application.

Gibberellic acid has shown to enhance ratoon yields the past two years of research using ProGibb 4% at a rate of 4 oz (4 grams ai) here at the Rice Research Station, especially whenpaired with stubble management. We will continue to evaluate gibberellic acid effects on ratoon regrowth and if it has a positive and consistent response over a 3-year period, we willmake it an official recommendation.

In the northeastern rice producing parishes, a lot of the rice is nearing mid-tillering. Some areas have had enough sporadic rainfall over the last few weeks to keep fields just wet enoughto keep preflood N from going out on dry ground.

This has delayed the establishment of the flood in some cases and caused producers to spoon feed the nitrogen in others. It is always best to apply the nitrogen on dry ground and thenflood up to get the highest efficiency of the fertilizer application.

However, when the rice gets nears mid- tillering we need to quit waiting and start spoon feeding the nitrogen fertilizer. I typically like to split the normal preflood rates into two separateapplications approximately 7-10 days apart. The mid-season season application would be the third application which would be triggered by the occurrence of green ring.

The mid-season window lasts from green ring (approximates beginning internode elongation and panicle initiation) until ½ inch internode elongation (approximates panicledifferentiation) which is approximately 10 days. When you see green ring, it is time to call the flying service.

Drain Timing

Drain timing is not an exact science, but we do have some guidelines that you can follow to help you estimate when a field should be drained. We use changes in the color of the panicle to help us determine drain timing.

  • Evaluations of panicle grain color should be based on the average of the field and not just the edges of the field. Generally, field edges will be more mature than the interior ofthe field.
  • For clay soils we recommend that the average of the panicles sampled need to have straw-colored grains from the tip of the panicle to half-way down the panicle.
  • For silt loam soils we recommend that the representative panicle sample have straw-colored grains from the tip of the panicle to ¾ of the way down.
  • In general, this equates to approximately two weeks for silt loam soils and three weeks for clay soils.

The optimum grain moisture at harvest for rice to maximize grain quality and harvest efficiency is 18-22%.

Ernst Undesser
By Dustin Harrell and Michael Deliberto, Louisiana State University June 19, 2017