June 7, 2013 No. 2013-11
Dr. Jarrod Hardke, Dr. Gus Lorenz, Dr. Trent Roberts, and Dr. Bob Scott
“When you shift the gear and that little needle on the tach goes into the red and reads 9000 RPM, that’s BAD.” That’s how I feel about this season – we’re at 9000 RPM worth of rain and cold, that’s BAD.
Last week’s rainfall event was less than kind – reports of local totals ranging from 6 to 12 inches across the northern part of the state. Many fields were ready to cleanup, fertilize, and go to flood. Now we’re in the process of trying to let it dry, rebuild levees and try to get back on schedule. Once again, we’re left with making the best of a bad situation. Please call or email if we can help – some general pre-flood N recommendations will be provided in this week’s comments, but we’re seeing a lot of unique situations and to make the right decision it will require us to get out our thinking caps (I’ve been told that mine sometimes resembles a dunce cap, but it’s the only one I’ve got).
Picture 1. Another delay.
95% of the crop is in the ground according to the USDA crop progress estimate. If you have the option of going to something other than rice – I’d call myself 100% done with planting rice. It’s extremely late in the season and we’ve already been forced to take a number of risks to get a lot of this crop in. Farming can be fun – but planting a rice field with nothing to show for it at the end is just the opposite of fun.
A few scattered rain chances over the weekend, but the real weather news will be the temperatures. Next week it looks like we’re going into the 90’s and we’ll stay there for a while. 95 is the highest number I’ve seen and some warmer nights will be approaching 75 for lows. We don’t want the low temps to stay that elevated, but it’s definitely time for us to settle into the mid-90’s for highs so that we can maximize our heat units.
Table 1 shows the projected flood dates for rice acres currently enrolled in the DD50 program. What you’ll notice is that while the numbers haven’t really changed from last week, a lot rice acres were hit with last week’s heavy rain at exactly the wrong time. By the time we get those fields patched up and ready to go, we’ll be fast approaching ½” IE, which is shown in Table 2. This is the time to be asking questions about how to manage your fertilizer – as water comes off these fields we need to move as fast as possible to keep the rice from falling too far behind.
Table 1. Percent of rice acres going to flood during listed weeks of 2013 according to current DD50 enrollment.
|May 29 – June 4||51%|
Table 2. Percent of rice acres to reach ½” IE during listed weeks of 2013 according to current DD50 enrollment.
|½” IE Date||Percent|
|June 29 – July 5||28%|
Early N Application and Management
There is a 2-week window to apply pre-flood N. We know what we want to do, but this year continues to tell what we can’t do. So how should you go about attempting to manage the pre-flood N for all these fields given the problems we’re having?
- Every effort should be made to apply the early N onto a dry soil surface. This is the recommended practice and helps us get the most out of our application.
- You missed or are about to miss the window and can’t apply pre-flood N onto dry soil on time. Then use NBPT-treated urea and apply the pre-flood N onto the muddy soil, but wait until the soil dries before flooding to minimize ammonia volatilization loss. The flood will not be able to incorporate the urea below the soil surface if the soil is not dry and ammonia volatilization will not cease when the soil is flooded.
- You can’t get the water off the field and a flood remains. Do not, for any reason, apply the large pre-flood N into the flood in a single application. Doing this is very inefficient and most of the N is lost within 7 to 10 days after application and before the young rice can use it. Simply increasing the N rate WILL NOT fully compensate for the amount of N lost. If rainfall keeps the field flooded and pre-flood N must be applied into the floodwater, then it is best to increase the early N rate and split apply the pre-flood N every week in increments of 30-45 lbs N/acre per application until internode elongation.
2013 Recommended Nitrogen Rates and Distribution for Rice Varieties in Arkansas
Picture 2. It’s a lake… it’s a pond… no, it’s a rice field. (Photo courtesy of Lance Schmidt)
In the Field
We’re seeing a great deal of discolored, sick looking rice up and down the state. Given what this crop has been through, regardless of when it was planted, there seem to be a lot of issues with the crop tolerating what should be normal rates of herbicides. The ALS herbicides are causing frequent yellowing – in severe cases we’ve recommended pulling the flood off to reduce stress on the rice. In less severe cases the rice seems to grow out of it in the flood and symptoms fade away.
Picture 3. Yellow spots or streaking can be found in many fields right now.
I have not observed rice midge (blood midge) in a dry-seeded drilled rice field before – cross that off the list. They’re typically a problem in water-seeded rice. I’ve heard people mention seeing them in dry-seeded fields around wellheads where water remains pooled early in the season, but we found a spot where they were thick as thieves. Recommendation is to drain and dry the field to reduce the number of midges. There were also some other problems in the field which led to the decision to drain.
Picture 4. Blood midge infesting rice roots in high numbers.
Grape colaspis has also begun to rear its head in fields that did not receive an insecticide seed treatment. Particularly on prairie soils, this pest can be extremely damaging and will remind you that the insecticide would have been cheap insurance.
As we go to flood, remember that rice water weevil begins to move in at that time. You should be concerned if your field doesn’t have an insecticide seed treatment. If you don’t have one and you have a thin stand – be prepared for it to get worse because rice water weevil adults are attracted to thin stands.
Need Help with DD50 Enrollment? Call or E-mail Me or Your Local County Extension Agent
If you prefer to enter them yourself, please visit http://dd50.uaex.edu/dd50Logon.asp.
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