Joseph Lofthouse, Landrace Seedsman [ Home | Status/Forum | Seed List ] [ Buy my book]

Sweet Corn Breeding

I am breeding an open pollinated landrace of homozygous sugary enhanced (se) multi-colored sweet corn on my farm in Paradise Utah. I call it "Paradise Sweet Corn" in honor of the town where it was developed. Paradise sweet corn contributed genes to "Lofthouse Sweet Corn" an su/se hybrid which is named in honor of my father who has gardened for decades in Paradise.
multi-colored sweet corn
multi-colored sweet corn
I planted alternating blocks of non-proprietary hybrid sweet corns (homozygous for the se gene, and mixed to provide a wide range of maturity) with open pollinated landraces of sweet corns and Indian corns. The landraces were detassled so that all the pollen was contributed by the homozygous sweet corns. Most of the sugary enhanced sweet corn (fathers) were sold at market, except that some ears were saved for use as a de-hybridized population of sugary enhanced sweet corn.

The breeding program is a cooperative venture with other great plant breeders and is using their partially enhanced segregating sweet corn seed as a starting point.

The sugar content of cobs from each plant is measured when they are at the fresh eating stage. I start by cutting off the end of a cob and tasting it. This separates ears into low, medium, and high sugar and a few that are just nasty. The taste test would be sufficient to develope a really sugary and nice variety of open pollinated sweet corn.

The amount of sugar can also be measured (approximately) by squeezing some juice from one kernel directly onto the sample window of an inexpensive refractometer calibrated in percent sugar. Some cobs contain around 10% or less sugar and some contain up to 30% sugar.

Sugary enhanced kernles may be selected before planting by tossing them into a cup of water and observing how fast they absorb water. Sugary enhanced kernels plump up quickly (12-48 hours depending on variety), while normal sweet corn kernels stay wrinkled for a long time. I use this method for selecting seeds for planting the day before they go into the ground. Damaged kernels also plump up quickly regardless of genetics and can be eliminated early on. An alternate method of bulk selection is to drop the seeds into a sugar water solution (3 parts sugar to 2 parts water) just before planting to separate them based on density. (Most sugary enhanced seeds sink while normal sweet corn and flour corn usually float.)

Seeds from non se+ cobs are saved in bulk for backcrossing or segregating the following year.

 Difference in kernel shape with and without the se gene in sweet corn
Normal Sweet Corn on the Left
Sugary Enhanced on the Right

percent sugar in segregating F2 sugary enhanced sweet corn percent sugar in segregating F3 sugary enhanced sweet corn
Expected sugar per cob in segregating F2 and F3 hybrids, based on genotype of mother.

Honorable Mention
Special thanks goes out to early plant breeders who have contributed genes to this project including: Dave Christensen's Painted Mountain, and A. Kapuler's Rainbow Inca and Painted Hills and thanks also to every indiginous farmer and prudent gardener that ever saved corn seeds for planting next year. Sweet corn varieties that have contributed genes to my landrace include old-time favorite heirlooms, and the best producing modern hybrids, such as: Astronomy Domine, Blue Jade, Millersburg Red, Millersberg Red #2, Millersburg small, Red 101, Martian Double Red, Triple Play, Black Mexican, Black Puckers, Country Gentleman, White 101, Hopi-Pink Sweet, Hookers, Howling Mob, Double Standard, Double Red, Washington County Orange, Silver King, Golden Bantam, Ashworth, Pastel Colors, Early Festival Multicolor, Rainbow Inca, Painted Hills, Luther Hill, Ruby Queen-se, Precocious-se, Bodacious-se, Incredible-se, Ambrosia-se, Tuxedo-se, Cocopah, Nueta, Aunt Mary's, Anasazi sweet, Colorado Sweet Indian, and many unnamed varieties that are maintained by small-scale farmers and home gardeners. Seeds from many Indian corns are being incorporated into the sugary enhanced landrace as they are obtained and the su1 and se genes are back-crossed into them. Varieties that were introduced into the program in 2010 include: Joseph's white dent, Joseph's red dent, Joseph's purple, Anasazi flour, popcorn, Joseph's flint and flour landrace, Nevada black Aztec-su and Black Aztec-su, Peruvian purple, Earthtones dent, Taos blue, Hopi blue, Hopi pink, Missouri sweet indian-su, Missouri flour, cherry flavored flour corn, Triple play-su, Painted mountain, Martin Jewels, and Farm-stand indian-su. During the 2011 growing season the genetic base was expanded to start including corns from the Mexican highlands race which is currently underrepresented. The new varieties being crossed and trialed included: Oaxacan Black pyramid, Posole, Maricopa sweet, Anazasi Flour, Anasazi sweet, Oaxacan green, and Hopi greasy head. Additionally in the 2011 growing season the descendents of a couple hundred varieties of sweet corn were incorporated into the breeding program.
Due to the strange economic conditions this year I am not selling seeds. Some varieties of my seeds can be obtained from:
Experimental Farm Network
Giving Ground Seeds
Snake River Seed Cooperative
Wild Mountain Seeds
Seed Savers Exchange
High Ground Gardens
Baker Creek Seeds
Miss Penn's Mountain Seeds
Hawthorn Farm Organic Seeds

If I missed anyone please let me know, and I'll add you to this list.

For other varieties, I may be willing to gift non-tested seeds if you'll cover postage which is about $5 per shipment. I welcome donations to help with my work of developing new genetically-diverse landrace varieties, and feeding my community. Please communicate with me before requesting seeds.

My Other Landraces

Landrace garden crops

Warm Regards,

My book, Landrace Gardening, is available from at For international sales, search the title from your local Amazon affiliate. Visit to request autographed author copies, or for a list of other vendors.


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