This was the staple breed used by the Incan Empire in their heyday, and it continues to be the chief commercial corn grown in Peru’s highlands. Andean corn is notoriously fussy, but it has some useful traits, especially its cold tolerance and resistance to common rust (Puccinia sorghi).
This particular population isn’t of pure Andean constitution; rather, it carries roughly 5% (3/64) Corn Belt Dent genetics so that under long days it will bloom in a timely manner, make grain, and not grow profusely tall.
The breeding work started with E. E. Gerrish at Cargill, Inc. back in the ’70s. He initially crossed early Minnesota dent corn onto a Cusco variety, and then mated back to Cusco 3 times, adding additional varieties in each step until he used 7 total. From there, Mr. Gerrish gradually reselected the population until it had a maturity and growth habit suitable for Iowa, while maintaining 15 / 16 of the original Cusco DNA by pedigree.
The University of Guelph in Canada took Gerrish’s population and selected it further for fast maturity, narrowing down the genepool in the process. Dr. Frank Kutka mated this early version with 7 additional Cusco or mixed Andean populations. I crossed his (Cusco del Norte) with a selection that I made from Gerrish’s original, and this seed is the result.
Cusco is…a handful in Tennessee, so why keep the stuff around? Because I saw first hand how well it takes cold nights. Back in 2014 we had a cold snap in the middle of May that lasted a week. Days in the mid-60s’F and nights around 40’F. My corn was just beginning to emerge when the cold hit. Everything turned yellow and sickly…except Cusco, which stayed green and healthy throughout. High elevation Andean corns have the capacity to grow at temperatures below the base 50’F typically stated as corn’s bottom limit. This means that it will put on more growth with less heat than mesic and heat-loving varieties.
Cusco probably isn’t the best candidate for a garden stalwart, but it would contribute quite a bit to the genepools of breeders and growers in cool places. Cusco gives high heterosis with Northern Flint (Dr. Kutka, personal communication) and seems like a great complement for folks who use that type.
I’m selling Cusco this year, though I don’t have nearly as much seed as my other offerings.
Maturity is roughly 55 days to bloom here, plus another 50 days to ripen the grain. Height is 5 – 6 feet. I used 200 plants for seed.
**Note** If you live in a wet area: I suggest that you pick the ears when the husks have completely died and then shuck and dry the ears in the sun or indoors with adequate air flow. Don’t let them field dry, or you may have spoilage. Flinty Cusco ears are less prone than floury ones.