Lessons learned

Researchers fine-tuned N, seeding recommendations for Provisia rice during 2018 season.

Dustin Harrell, LSU AgCenter rice specialist

DR. DUSTIN HARRELL
LOUISIANA
Extension Rice Specialist
dharrell@agcenter.lsu.edu

The 2018 season was the first year the Provisia variety, PVL01, was grown commercially. Louisiana grew approximately 10,000 acres of PVL01, and the average yield was about 42-43 barrels per acre statewide (6,804-6,966 pounds per acre; 151-155 bushels per acre).

Many growers were satisfied with the Provisia system, and I expect Provisia acres will increase in Louisiana in 2019.

The Provisia technology was, and still is, desperately needed in Louisiana to clean up Newpath-resistant red and outcrossed rice in infested fields. Because of the great need for the system, the variety PVL01 was developed faster than any other inbred variety in the history of the H. Rouse Caffey.

Rice Research Station in Crowley, Louisiana. Prior to the release of any variety, research is conducted for several years to evaluate the optimum nitrogen rate and plant population. Because the variety was fast-tracked for release, less-than-normal data existed to make agronomic recommendations.

Some key findings

Recommendations were made based on existing data that suggested the variety needed 30 more pounds of N per acre to reach its yield potential compared to most other currently grown varieties. Additional research was conducted in 2018, and the new findings indicated the variety responded similarly to other varieties being grown. Therefore, the recommendation was reduced in Louisiana to 120-160 pounds of N per acre for 2019.

Data collected prior to PVL01’s release and data collected in 2018 suggested the optimum plant population was 10-15 plants per square foot at the three-leaf stage of development. The recommended seeding rate is 50-70 pounds of seed per acre. The canopy of PVL01 is very thick, and many question if seeding rates can be lowered even further.

In truth, seeding rates could go as low as 23 pounds per acre, and a plant population of 10-15 plants per square foot could theoretically still be achieved. However, every seed would have to germinate and every seedling would have to survive to maintain the optimum plant population.

Losses due to biotic and abiotic stresses could potentially reduce seedling populations below optimum. The current recommended seeding rate considers this and provides a buffer for these potential losses.

What you need to know

Provisia Rice

This Provisia Rice near Kaplan, La., was planted in a field with a history of weedy rice problems.

If you have never grown PVL01 before, you should also know these additional facts before planting it in 2019:

1. You cannot plant PVL01 after Clearfield rice due to the Newpath residual.

2. The Provisia herbicide does not have a residual component. Use residual herbicides in your herbicide program and overlap when possible.

3. Antagonism has been reported when tankmixing Provisia with several herbicides. Avoid all tankmixes when possible.

4. A “yellow flash” can sometime be seen after Provisia application. This will generally go away after a few days of good growing conditions.

5. PVL01 is a lighter green color than most rice varieties and will not turn that dark green color regardless of how much nitrogen fertilizer you apply.

6. PVL01 is susceptible to blast. You will need to use at least one fungicide application, and it is highly recommended that you use two applications when growing PVL01.