Top Hat

Sweet Corn with 7-1/2” ears with 16 rows of kernels. The Top Hat corn story: Nearly all of the improvements in sweet corn in the last half century or more have been bred as hybrids. Open pollinated (OP) varieties, ones from which you can save seed, are way behind. Fortunately, this should not be too hard to remedy.

One of the simplest methods to make a more modern OP variety is to choose a good hybrid and “de-hybridize” it. This is done by growing out the seed and saving and replanting the best for several generations until it is reasonably stable.

In 2002 I planted out rows of 16 commercial hybrid sweet corn varieties, just to pick the best one. I chose Tuxedo. It was the first to germinate and it grew ears with a long husk cover that is some protection from insect damage. It held up pretty well under weed pressure and produced a fairly consistent 2 ears per plant.

The next year I grew a field of Tuxedo, saving 300 or more nice ears for seed. The following year we planted those seed. “Top Hat” corn is (2013) seed from the sixth generation from Tuxedo.

Tuxedo is supposed to uniformly possess the sugary enhancer (se) gene, so I did not expect lack of sweetness to be an issue. I found, however, in the f3 generation when I started conducting taste tests, many of them weren’t all that sweet. So began the search for sweetness.

I selected only among plants with two good ears. I tasted the secondary ears and marked for keeping only the primary ears from the sweeter plants, about half of the population. This should increase sweetness in subsequent generations, but it could be a slow process.

Dr. Carol Deppe first told me that an individual sweet corn kernel that has more sugar will begin to wrinkle more slowly as it starts to dry sown. Dr. Alan Kapuler said he had made use of this principle. Dr. John Juvik explained why it works; that increased sugar causes greater osmotic potential or pressure from inside the kernel, causing that kernel to maintain plumpness for a little longer before the onset of wrinkling. If some kernels on the ear are sweeter than others, could I pick those out and get more quickly to uniformly sweet corn ? I decided to find out.

I had tasted the secondary ear on each stalk when the corn was ripe to eat, and flagged the primary ear of the sweeter ones left on the stalk. I harvested these chosen and flagged ears about 2 weeks past prime eating stage, but before fully mature for seed. I husked the corn, and I began to see wrinkling, placed the ears up so they got air all around. Some kernels start to wrinkle up faster than others. When some, but not all, have started to wrinkle, I used a felt marker to paint those last kernels not yet wrinkled. I then put the entire ear up to dry and picked out the painted kernels from the corn after it was dry. Only those painted kernels were used to grow the next generation.

This was repeated for two more generations, with sweeter ears chosen by taste, and slowest to wrinkle kernels from those ears marked. In 2013 I grew out seed from the sixth generation. I hope you enjoy Top Hat corn.Jonathan Spero Lupine Knoll Farm, 2014.

This is Open Source Pledged Seed (OSSI). By purchasing this seed you are a part of the Free The Seed movement. This variety is registered as an OSSI-pledged variety and seed. “You have the freedom to use these OSSI-Pledged seeds in any way you choose. In return, you pledge not to restrict others’ use of these seeds or their derivatives by patents or other means, and to include this pledge with any transfer of these seeds or their derivatives.” To learn more, visit: www.osseeds.org/about/.