March 20, 2015 No. 2015-5
Dr. Jarrod Hardke, Dr. Gus Lorenz, & Dr. Tom Barber
“Well, we’re waiting…” Slight rain chances today and tomorrow followed by a 50% chance on Sunday lead into a few days of 70 degree weather. More rain is in the forecast for Wednesday and Thursday though, which means the reality is the 2015 growing season for rice or any other crops won’t really begin until April. Despite early wet and cool conditions in 2013 and 2014, we did manage some early plantings in March those years. Against the odds, we seem to be on a similar path to those years, only more delayed. My worst fear, which I don’t even like writing, is that a tremendous amount of precipitation this early has the potential to lead to the water faucet being turned off as we get into the swing of things this year. I made that statement last year and it never happened – who says Mother Nature doesn’t have a sense of humor? However, we’re never more than two weeks away from a drought, if it ever warms up.
Nitrogen Fertilizer Recommendations
The 2015 Recommended Nitrogen Rates and Distribution for Rice Varieties in Arkansas is now available.
Seed Treatments – What’s In A Name?
There are a number of seed treatment options available for rice and it’s important to know what you’re getting on the seed. A simple misunderstanding of the ingredients in each product can lead to problems not easy to correct once the seed is in the ground.
CruiserMaxx Rice contains both an insecticide (thiamethoxam) and fungicides (fludioxonil, azoxystrobin, and mefenoxam). NipsIt INSIDE contains only an insecticide (clothianidin). NipsIt Rice Suite, available upon request, contains both an insecticide (clothianidin) and fungicides (fludioxonil and metalaxyl). Dermacor contains only an insecticide (chlorantraniliprole).
Although we strongly recommend the use of an insecticide seed treatment, some growers choose to treat seed with fungicides only. For fungicide-only seed treatments there are many options that help prevent both pythium and rhizoctonia seedling diseases and rots, including Vitavax + Allegiance FL, Apron XL LS + Maxim 4 FS, Dynasty, Trilex 2000, EverGol Energy, and CruiserMaxx Rice (which also contains an insecticide).
See Table 1 for an overview of insecticide and fungicide seed treatment options. To protect early-season stand and ultimately yield, we recommend using seed treatments that contain both insecticides and fungicides. Choose the most cost-effective set of treatments that provides you with protection from diseases and insects.
Table 1. Seed treatment products for rice and description of use.
Seeding Rates & Drill Calibration
The RICESEED program has been updated for 2015 and can be found at http://riceseed.uaex.edu. This online tool can be used to select an appropriate seeding rate based on cultivar, soil type, seedbed preparation, planting date, and seed treatment. Consideration of each of these factors is extremely important in achieving a successful stand density.
Drill calibration can be difficult – especially when alternating between varieties and hybrids. A spreadsheet has been provided to make these calculations easier – found on the RICESEED webpage listed above. Since it’s not always very convenient to have a computer handy to make calibration changes – along with this newsletter is a simple worksheet that provides the steps needed to accurately calibrate, you’ll just need a calculator to generate the numbers yourself.
The improved DD50 program is now up and running at http://DD50.uaex.edu. Changes have been made to improve your experience on both your computer and your mobile devices. Please let us know what you think about the changes and usability of the program.
Tearing It Up and Burning It Down
Burndown applications are first on the priority list these days. The rain has us running a little late on the calendar for burndown applications, but if you look at what is growing in the fields, winter annuals have also been delayed due to the extended cold weather. Before making burndown applications, decide which crops will be planted to make sure the re-plant intervals following herbicide applications will match up well with the intended crop. For all burndown applications refer to the MP519 Row Crop Plant-Back Intervals for Common Herbicides publication for replant guidelines. The key to success with any burndown program is first to know what weeds you have in the field and second, wait at least 14 days after application to be certain that the weeds are dead prior to planting. This will save some headaches later in the season, with weed and insect pests.
Roundup + 2,4-D + Sharpen is an excellent burndown option in front of rice. However, the plant-back window for 2,4-D is 21 days. Roundup + Sharpen (2 oz/A) will control most annual weeds including glyphosate-resistant horseweed if it is small. If horseweed has any size, especially once it starts to bolt; it will most likely regrow if 2,4-D is not included with the Sharpen.
Roundup + FirstShot is also an excellent option with an immediate replant interval, and this combination will control most all winter annuals with the exception of glyphosate-resistant horseweed. Gramoxone is an option with no pre-plant interval to rice, and is good on most winter annuals as long as they are small. Following the initial burndown application, Roundup tank-mixed with Command and/or other PRE herbicides will help finish off winter annuals or early grass flushes at planting.
Will the Season Begin with Water-Seeding?
With the persistent rainfall delaying our ability to get in the field with ground equipment, I realize some will start to swap over to trying their hand at water-seeding. Certainly this is an option that can work well, but there are some things to keep in mind if you have little or no experience with it in the past.
Field preparation – did you prepare the field with water-seeding in mind? If so, get after it when the weather is right. If you didn’t, then there are some factors to consider. If the field is slicked off then you’ll have difficulty getting the seed to hold in place when flown on. A few ways to help with this – pre-sprout the seed, keep a minimum flood depth of no more than a 1-2 inches to minimize seed drift, back the field down to muddy as soon as the seed pegs down.
A completely slicked off field is probably the most risky situation for water-seeding due to the risk of seedling drift. If you have access to a track tractor and a cleated roller, one tactic is to run the roller over the field while it’s a little damp and basically turn the upper 1-inch into “pudding”. Seed flown into the pudding will stick and sink into the mud immediately. Success can be had with this method using dry seed as well as pre-sprouted seed.
Fields that still have a rough surface from discing or other tillage are better candidates for last-minute decisions to water-seed rice. In these fields, pre-sprouted seed will fall to the lowest points, which will be in the cracks created by clods in the field. Follow the other general methods mentioned above, but here the risk of seedling drift is greatly reduced.
For pre-sprouting rice seed: 24-36 hours soaking in water followed by 24-36 hours out of the water – then fly it on.
Seed treatments in water-seeded rice: CruiserMaxx Rice or NipsIt INSIDE treated seed cannot be water-seeded. Period. Labels for the fungicides Apron XL, Maxim XL, and Dynasty do not prohibit aerially broadcasting or water-seeding rice. However, they cannot be pre-soaked – must be flown as dry seed. If you fly dry fungicide-treated seed into standing water you likely won’t get much benefit from them because it will be lost in the water.
Dermacor is the only insecticide-seed treatment labeled for water-seeding in rice. Since rice water weevil infestations are worst in water-seeded rice, this is good since Dermacor is the best seed treatment for rice water weevil management. Seed treated with Dermacor cannot be pre-soaked and must be flown on dry.
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More information on rice production, including access to all publications and reports, can be found at http://www.uaex.edu/farm-ranch/crops-commercial-horticulture/rice/.
We sincerely appreciate the support for this publication provided by the rice farmers of Arkansas and administered by the Arkansas Rice Research and Promotion Board.
The authors greatly appreciate the feedback and contributions of all growers, county agents, consultants, and rice industry stakeholders.