Oklahoma Farm Report masthead graphic with wheat on the left and cattle on the right.
Howdy Neighbors!
Ron Hays, Director of Farm and Ranch Programming, Radio Oklahoma Ag Network  |  2401 Exchange Ave, Suite F, Oklahoma City, Ok 73108  |  (405) 601-9211

advertisements
   
   
   
   
   
   
   
   

Agricultural News


Why Do Sunflowers always Face The East?

Fri, 13 Aug 2021 08:04:48 CDT

Why Do Sunflowers always Face The East? Sunflowers face the rising sun because increased morning warmth attracts more bees and also helps the plants reproduce more efficiently, according to a study by researchers at the University of California, Davis. The results were published Aug. 9 in New Phytologist.

"It's quite striking that they face east," said Stacey Harmer, professor of plant biology in the UC Davis College of Biological Sciences and senior author on the paper. "It's better for them to face east, as they produce more offspring."

While sunflowers are growing, their heads turn back and forth to track the sun during the day. Previous work from Harmer's lab showed that this tracking is controlled by the plant's internal circadian clock.

But as the flower heads, or capitula, mature and their stems become stiff and woody, this movement decreases until the heads are all facing the morning sun.

advertisement

When postdoctoral researcher Nicky Creux changed the orientation of sunflowers by turning their pots around, she noticed that east-facing flower heads attracted a lot more bees, especially in the morning, than plants facing west.

In a series of experiments, Creux, Harmer and colleagues found that the east-facing heads were significantly warmer in the morning than west-facing flower heads. That warmth brings an energy benefit to foraging bees early in the morning, Harmer said. Direct sunlight also lights up ultraviolet markings on the flower petals that are visible to bees but not to human eyes.

Orientation affects pollen release and flower development

A sunflower is actually a composite of hundreds, sometimes thousands, of individual flowers. These individual florets develop first at the outer edge of the flower head, forming characteristic spiral patterns.

The orientation of the plants also affected flower development and reproductive success. East-facing plants tended to produce larger and heavier seeds. They also released pollen earlier in the morning, coinciding with the times when bees visit.

These effects seemed to be controlled by the temperature at the flower head. When researchers used a portable heater to warm up west-facing heads, they were able to get similar results to east-facing flower heads.

Finally, Evan Brown, an undergraduate student supervised by Ben Blackman at the University of Virginia, took sterile male plants, which could produce seeds but not make pollen, and surrounded them with normal plants facing east or west. Using genotyping, they were able to distinguish whether the male-sterile plants were pollinated by east- or west-facing plants. The team found that pollen from the east-facing plants was responsible for more offspring than that from west-facing plants.

The work was supported by grants from NSF and the U.S. Department of Agriculture-National Institute of Food and Agriculture.


   


 

WebReadyTM Powered by WireReady® NSI

 


Top Agricultural News

  • Regenerative Agriculture: Past, Present and Future  Tue, 28 Sep 2021 17:14:16 CDT
  • Oklahoma Grain Elevator Cash Bids as of 2 p.m. Tuesday, September 28, 2021  Tue, 28 Sep 2021 16:45:58 CDT
  • Tailgate Celebrates New Frontiers Donors and Progress for New Home for OSU Agriculture  Tue, 28 Sep 2021 15:24:01 CDT
  • Fort Sill Apache and USDA NRCS Work Together to Grow a Promising Tomorrow  Tue, 28 Sep 2021 14:13:21 CDT
  • Beef Cow Herd Liquidation Continues to Unfold  Tue, 28 Sep 2021 12:48:00 CDT
  • BLM Recognizes Ranchers for Exemplary Stewardship of Public Rangelands  Tue, 28 Sep 2021 12:39:37 CDT
  • Farmers Urged to Return Custom Rates Survey to OSU Extension ASAP  Tue, 28 Sep 2021 11:36:34 CDT
  • Soil Conservation Project Receives Grant From Texas Water Development Board  Tue, 28 Sep 2021 10:46:56 CDT

  • More Headlines...

       

    Ron salutes our daily email sponsors!

    Oklahoma Beef council Oklahoma Ag Credit Oklahoma Farm Bureau National Livestock Credit Ag Mediation Program P&K Equipment Tulsa Farm Show Union Mutual Stillwater Milling Oklahoma Cattlemen's Association KIS FUTURES, INC.

       
       

    Search OklahomaFarmReport.com

    © 2008-2021 Oklahoma Farm Report
    Email Ron   |   Newsletter Signup   |    Current Spots   |    Program Links

    WebReady powered by WireReady® Inc.