June 28, 2013 No. 2013-14
Dr. Jarrod T. Hardke, Dr. Gus Lorenz, Dr. Bob Scott, and Dr. Yeshi Wamishe
Much of the crop (~60%) has reached 1/2” internode elongation. There are still some extremely late planted fields that haven’t even made it to flood, but hot temperatures will get them there soon enough. Most fields seem to be growing off nicely and out of early problems.
If you’re worried about how far behind your rice crop is – I understand, but let’s look at things a little closer. Last year (2012) was probably about the earliest anyone I know has ever harvested a crop. My father has grown rice for over 30 years – it was the earliest rice crop he can remember. DD50 projections for when 80% of the crop will reach harvest moisture were Aug. 17-23 in 2012 compared to Aug. 31-Sept. 6 in 2013. I know 2 weeks is a lot of difference when we’re talking about trying to get a crop harvested. Look at the reality of that 2 week difference though – 2012 was the earliest harvest anyone can remember, and 2013 is the most delayed crop anyone wants to remember and there’s still only a 2 week harvest difference.
Rice is an amazing crop. It is very resilient and forgiving. It will make up for lost time and probably only be about a week behind when we normally find ourselves reaching harvest.
On to less positive thoughts – disease has reared its ugly head in the state. So far reports are limited, but blast and sheath blight have been confirmed. There are also some possible problems with insecticide seed treatments on early-planted rice. Be on the lookout and read more about these issues later in the newsletter.
Tables – Percent of rice acres to reach growth stages during listed weeks of 2013 according to current DD50 enrollment.
|1/2" IE Date||Percent||50% Heading Date||Percent||Harvest Date||Percent|
|Reached 1/2" IE||58%||July 5-11||2%||Aug. 10-16||1%|
|June 29 - July 5||24%||July 12-18||31%||Aug. 17-23||25%|
|July 6-12||11%||July 19-25||32%||Aug. 24-30||26%|
|July 13-19||5%||July 26 - Aug. 1||20%||Aug. 31 - Sept. 6||28%|
|July 20-26||1%||Aug. 2-8||10%||Sept. 7-13||13%|
|Aug. 9-15||3%||Sept. 14-20||4%|
|Aug. 16-22||1%||Sept. 21-27||2%|
Rice blast and sheath blight are now active (as of the 4th week of June) in Arkansas. Read more at: http://www.arkansas-crops.com/2013/06/26/rice-blast-sheath-blight-active-now/.
USDA-NASS Releases Crop Acreage Report
Total Arkansas rice acreage for 2013 is 1.061 million acres, down from a March projection of 1.226 million acres. This represents a reduction of 230,000 acres compared to 2012. Arkansas acreage information by year and class is provided in Table 1.
Table 1. Arkansas rice area planted by class in 2012 and 2013.
|Class & State||
* The full acreage report, including additional information for other states and the U.S., can be found here:
Out Standing in Your Rice Field
Hydrogen Sulfide Toxicity
Please be aware that suspected cases of hydrogen sulfide toxicity (Akiochi/autumn decline) are being found in the state (Picture 1). In some cases stand has been lost and most likely some yield potential even on surviving plants. Fields in Ashley and Lafayette Counties displayed the suspicious symptoms of this issue at an early growth stage (permanent flood). Read more on the scouting method, symptoms, and management at: http://www.arkansas-crops.com/2013/05/23/weather-and-akiochi-disease-of-rice-is-there-a-link/.
Picture 1. Rice plant displaying suspected hydrogen sulfide toxicity symptoms.
Herbicide carryover is real. We have a very difficult time duplicating the occurrence in plot research most likely due to a wide range of variables at work in causing carryover symptoms. Have a look at Picture 2. I see soybean rows from the previous year – that would be fomesafen carryover from a late June 2012 application on soybean to rice planted in mid-April 2013. That’s less than the 10-month plantback restriction for products containing fomesafen. Not everyone will see a carryover, but some will and it’s a risk each time you don’t obey the plantback restriction.
Picture 2. Soybean row effect from suspected fomesafen carryover.
Spray tank contamination and drift are also still being seen around the state lately. These problems are very unpredictable, but also very avoidable. A little extra care can go a long way in preventing problems like these that we can’t afford, especially with an already late crop.
Rice Water Weevils and Insecticide Seed Treatments
This week we started washing our first rice water weevil samples of the year. As we started looking at the numbers it became immediately apparent that we couldn’t separate the insecticide seed treatments from the untreated check. This is not what I am accustomed to seeing in our trials. Usually the seed treatments (in this case Cruiser and NipsIt) have considerably fewer rice water weevil larvae than the check. Unlike most of you I am sure, I first try to figure out who to blame when stuff goes wrong, but since we treated the seed and I know it was planted right, I was in a quandary and finally came to the conclusion that something else might be involved.
I finally figured it out. We checked the planting date – it was March 28th. So if you do the math it comes out to 88 days since planting. We can hardly expect these seed treatments to still be working after that amount of time, not to mention all the rainfall and subsequent water traveling through the soil profile. Obviously this is an extreme situation, but I bet there are some folks out there that may have 40+ days since planting and are putting on flood. In our case, when the flood went on 21 days ago and the weevils moved into the field, the seed had been in the ground for 67 days.
So remember to figure the days on your fields to see if you are in a similar situation. If rice water weevil scarring and adult activity are high – a foliar application of a pyrethroid like Mustang Max, Karate Z, or Declare might be called for.
So what is a lot of activity you might ask? If 50% of new leaves have scarring and adults are present you may need to consider a foliar application. Remember that timing is critical on the application. It must be made 5-7 days after putting on the flood. If it is later than that, our studies indicate you may as well keep the insecticide in the jug. Your only option then is to drain the field until the soil cracks to prevent weevil damage. Most growers aren’t crazy about doing that as it is costly and may impact weed control and fertility. Rice water weevils are particularly high this year from our observations so get out there and scout those fields.
We didn’t have Dermacor in the trial – if we had it might have still been active. It is much less soluble and binds to the seed a lot more than the neonicotinoids (Cruiser and NipsIt). So if you have Dermacor on the seed you are probably still OK. Dermacor doesn’t slow down adult scarring as much as the other seed treatments so don’t assume it isn’t still there even if you do have scarring on the leaves from adults.
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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