“Why are there red potatoes in my field?”

Stephen Meyers, Sweetpotato Extension Specialist
By Stephen Meyers, Sweetpotato Extension Specialist October 7, 2013 12:03

“Why are there red potatoes in my field?”

Last week’s harvest saw reports of “red potatoes” appearing in sweetpotato fields.  There was speculation that the light-orange-skinned ‘Beauregard’ had altered its genetic make-up to the point that it had changed its skin color at multiple locations within the same field.  While genetic mutations do occur in sweetpotato, there is a far more likely explanation.  As a colleague of mine says, “The simplest answer is usually the right answer.”

DSC_0368

‘LA 07-146′ (second row from bottom) in a field of ‘Beauregard’.

DSC_0369

‘LA 07-146′ (top) and ‘Beauregard’ (bottom) sweetpotato storage roots.

What are these red potatoes?

‘LA 07-146’ is a relatively new sweetpotato variety from the LSU sweetpotato breeding program.  It has red to slightly purple skin, deep orange flesh, and a sugar content similar to ‘Evangeline’ sweetpotato.  The variety consistently yields 15-20% more than ‘Beauregard’.  While growers in Louisiana can grow ‘LA 07-146’ for the fresh market, its production outside Louisiana is restricted and requires a license from ConAgra Foods.  Despite its propensity to outyield current varieties, ‘LA 07-146’ has been grown by only a limited number of sweetpotato growers in Mississippi- and mostly on a trial basis.

 

How do varieties get mixed?

It is not uncommon to comingle sweetpotato varieties in the production setting.  However, most incidences of comingling are subtle as the vast majority of fresh-market sweetpotato varieties have similar leaf shapes and color and have storage roots with orange skin and flesh.  The comingling of varieties typically occurs when sweetpotato “seed” of one variety are accidentally bedded with another variety.  This can happen when the seeding buggy is not thoroughly emptied between varieties.  It can also occur when seed are saved from fields with multiple varieties planted near one another.  For example, if ‘Beauregard’ and ‘LA 07-146’ were grown next to one another in production fields, vines from ‘LA 07-146′ plants could grow into rows planted with ‘Beauregard’.  If the vines touch the soil, they can form storage roots that would likely reach canner size by harvest.  When the field is harvested, the ‘LA 07-146′ canners would be saved in a bin of ‘Beauregard’ for seed the next spring.  Often, the comingled seed will produce slips that are indistinguishable from one another and will be planted together in the production field the following season.

For growers who use the same field for sweetpotato production in consecutive years, it is possible that sweetpotato storage roots left in the production field can overwinter if winter conditions are mild.  These roots can then emerge the following spring and produce vines and storage roots.

 

Mutations do occur in sweetpotato.

Sweetpotatoes frequently mutate in the production environment.  The most obvious mutations occur as changes in foliage color (see below), or storage root flesh or skin color.  While mutations are common, the likelihood of several plants in the same field mutating the exact same way is implausible.

DSC_0380

Leaf variegation is one common type of mutation.

DSC_0372

Conclusion: In this case, the red potatoes appeared in the same row and in consecutive hills.  There was no mutation event or overwintered plants from the previous year.  It would appear that a few ‘LA 07-146’ slips were accidentally planted in a field of ‘Beauregard’ sweetpotato.  Despite even the best growers’ efforts to isolate varieties, mixing of varieties does occur.

 

Print Friendly
Stephen Meyers, Sweetpotato Extension Specialist
By Stephen Meyers, Sweetpotato Extension Specialist October 7, 2013 12:03
Write a comment

No Comments

No Comments Yet!

Let me tell You a sad story ! There are no comments yet, but You can be first one to comment this article.

Write a comment
View comments

Write a comment

Your e-mail address will not be published.
Required fields are marked*

Subscribe to receive updates

  • Soybean Harvest Aids

    Several calls have come in over the last week regarding soybean harvest aid options for various scenarios. In some cases, fields have been observed with varying degrees of maturity. In ...
  • Sugarcane Aphid Control with Falling Temperatures

    In 2014 we saw two brief time periods of less than satisfactory control with Transform on sugarcane aphids in grain sorghum across a broad geography. At the time we were mixing a ...
  • Pheromone Trap Counts, August 28. 2015

    Bollworm trap catches remained similar to last week, which is somewhat lower than average for this time of year. Tobacco budworm trap catches were somewhat higher this week. As most ...
  • Pheromone Trap Counts, August 21, 2015

    Bollworm moth trap catches were slightly higher in most counties this week but are generally lower than average counts for this time of year. Tobacco budworm moths continued to be ...
  • Defoliating Caterpillars in Peanuts

    We have had numerous calls over the last 2 weeks about caterpillars in peanut from all around the state. In every case, the calls have involved a complex of multiple species including bollworm/tobacco budworm, cutworms, armyworms, saltmarsh caterpillar, loopers, and rednecked peanut worm. ...
  • 3rd Annual Mississippi Sweetpotato Field Day Program- August 27th

    Mississippi State University will host its 3rd Annual Sweetpotato Field Day Thursday August 27 at the Pontotoc Ridge-Flatwoods Branch Experiment Station (8320 Hwy 15 S., Pontotoc, MS 38863).  Registration is ...

More Info By