Weed Suppressive Rice Cultivars
• Weeds are the most costly pest of rice production
• Herbicides are applied to most rice fields each year to control weeds
• Weed-suppressive rice can reduce herbicide use and benefit the environment
• Weed suppression may be due to rice root growth, height and tillering, or natural herbicides produced by the rice roots (allelochemicals)
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Under low weed populations,
rice varieties show dramatic
differences in suppression. |
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Rice plots planted in barnyardgrass-infested field. Weed-suppressive rice varieties (two photos at right) dramatically reduce weed population and growth when plants are young. This suppression can continue through maturity. |
Red Rice Outcrossing
- Red rice is a Crop 'mimic' that reduces yield, and produces undesirable red seeds. Both are the species Oryza sativa.
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Rough |
De-Hulled |
Milled |
| Strawhull Red Rice |
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| Awned Red Rice |
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Long-grain Rice |
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Medium-grain Red Rice |
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Rice X Red Rice Hybrid (medium-grain) |
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Year 1: Rice (dark green) and red rice (light green) are grown together to allow plants to outcross as they would in a farm field. |
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Year 2: Rice X awned blackhull red rice hybrids produce pink awns. |
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Year 2: Rice X awnless strawhull red rice hybrids flower very late (or not at all) and are awnless. |
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Year 2: Clearfield rice crosses at low rates with red rice. This produces small numbers of Herbicide-resistant hybrids that we confirm using DNA fingerprinting. |
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In this photo you can see remnants of the dead non-hybrids below the water's surface. These were killed with herbicide. |
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Research Support Staff:
Dr. David Gealy, USDA ARS, Research Plant Physiologist
Howard Black, USDA ARS, Plant Physiologist, Support Scientist
Bill Luebke, Biological Science Aid
Major Cooperators:
Nilda Burgos, University of Arkansas, Fayetteville
Karen Moldenhauer, University of Arkansas, Stuttgart
Merle Anders, University of Arkansas, Stuttgart
Brad Watkins, University of Arkansas, Stuttgart
Lew Ziska, USDA-ARS, Beltsville, MD
Mo Way, Texas A&M University, Beaumont
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