Fertilizer time. (April 24th)

I make my own blend for the little acre that my nursery occupies. I try to keep pH, macronutrients, and micronutrients as close to ideal as I can. After applying 3 tons of lime to the acre in 2019, my pH has been at a perfect 6.5 – 6.9. Local soils can sometimes dip into the 4.5 – 4.0 range, given their acid shale parent material.

In 2020, I had to add zinc. 2021, I needed extra boron and copper.

This year, I made a blend of the usual urea (nitrogen) and muriate of potash (potassium), plus some extra sulfur.

I’ll likely need to add a dose of magnesium via epsom salts, come autumn.

Goodbye, winter cover crop. Ground prep begins. (April 22nd & 23rd)

This was a blend of 65% cereal rye, 10% winter wheat, and 25% hairy vetch.

Due to constant rain events this April, I wound up terminating the stand about 2 weeks later than I had intended. The extra growth made it a pain to mow, but I got it done.

Because there was so much residue bulk, I needed to moldboard plow. I much prefer chisel plowing, but with any appreciable amount of “trash” on the soil surface, chisels function more like a rake.

More rye residue than I want to see but much less than I began with.

This was a crazy two days!

Elotero de Sinaloa, from western Mexico.

Last year I grew a small strip trial plot of this breed from western Mexico, and it performed surprisingly well in Tennessee. It’s a specialty roasting ear type, related to Elotes Occidentales and Bofo, both derived in part from Harinoso de Ocho.

Elote / roasting ear varieties from Mexico tend to be highly colored (blue, lavender, red, and / or cherry).

I might make this breed available for sale in the future if I feel that there is enough demand.

Zapalote Grande, a traditional breed from southern Mexico.

Here is yet another southern Mexican corn, though not as old as its relative, Zapalote Chico.

Z. Grande is native to Chiapas state and grows in wetter areas. I suspect that it is being pushed out both on the earlier and on the later sides by more specialized niche corns. As such, Z. Grande is becoming rather difficult to find in the current era. It is a general purpose corn where grown.

Z. Grande takes ~72 days to bloom and ~50 days to ripen its grain in Tennessee. Plants are 9 – 12 feet tall, mostly purple. Ears are short with low row number (10 – 16) and dented kernels. Husks are rather tight, numerous, and hard. Fairly disease-free here in Tennessee with the strongest resistance to Northern Leaf Blight that I’ve ever observed.

The seedstock was grown in 2021 and derived from 120 intermated plants.

A sample of the ears that constituted the seed stock.

Like Z. Chico, this is another variety that I wouldn’t recommend for use as is but for breeding material instead. The main value lies in its terrific resistance to Northern Leaf Blight, in 2020, 2021, and based on USDA-GRIN data.** If you live in a region where this blight is destructive, then Z. Grande is the most useful corn of mine that I can recommend.

sources cited:

**https://npgsweb.ars-grin.gov/gringlobal/methodaccession?id1=89009&id2=494398

Zapalote Chico, an ancient early corn from southern Mexico.

Here is another ancient corn from Mexico, this time from the southern part of the country (Oaxaca and Chiapas).

Zapalote Chico is a member of the same large group that includes Tuxpe├▒o, albeit a much smaller relative. It is found predominantly in dry areas with short rainy seasons, being able to mature in 85 – 90 days after sowing. It is reputedly capable of handling rather strong winds, due to the plants’ short, stout growth habit. Supposedly it makes excellent totopos (tortilla chips) too.

The plants are 6 – 7 feet tall, needing ~56 warm days to bloom, and daylength neutral despite coming from southern Mexico and having no previous selection for earliness. Grain ripening takes 45 – 50 days after pollination. Ears are short, and row number ranges from 10 to 14. Kernels are dented but rather soft, like Gourdseed. Husks are **EXTREMELY** tight, hard, and numerous. Very strong resistance to Southern Rust here after artificial inoculation.

Notice how tightly the husks wrap around the tip of the ear. Combined with husk number and hardness, this gives great protection vs. earworms. Moreso still when combined with silk maysin.
Same ear as above, shucked. Notice the great number of husks. They’re hard and coarse, unlike the softer husks of many temperate corns.

Seedstock was harvested in 2021 and traces back to 100 plants.

This population isn’t worthwhile as is due to its low yield, but it would make a great breeding resource. Z. Chico is the only variety that redwing black birds will largely leave alone here, due to the corn’s husks. It is nearly immune to earworm damage also. Southern Rust resistance is one of the best that I’ve observed too.

Almost no Southern Rust development on Z. Chico, even though I inoculated these plants ~28 days before the photo was taken. (The yellowing leaf in the middle was the one that I intentionally infected.)

Harinoso de Ocho, a nearly extinct ancient corn from western Mexico.

This breed has quite a history to it. It is one of the ancestors of the narrow-eared corns of Western Mexico and (likely) of US Southwestern types such as Papago Flour. I suspect that Harinoso de Ocho was also involved in the origin of Northern Flint-Flour, and it clusters closely in phenotype with Southeastern US 8 Row (Cherokee White Flour and Quapaw Red Flint).**

At present, H de Ocho is almost completely extinct as a breed in production, with only one “typical” (i.e. not heavily contaminated) collection held in seed banks. Its derivatives such as Tabloncillo and the colored elote corns are still widely grown in western Mexico, however.

Plants are 8 – 10 feet tall, with tillers common. Unlike most Northern Flint-Flours, however, this breed’s tillers have very little tassel seed (hermaphrodites), and many plants’ tillers will even produce fine ears. 2 particular individuals made 5 ears apiece for me last year! Row number ranges from 6 to 10, and ear length ranges from 9 to 12 inches (one was 15). Time to bloom in Tennessee is 72 days for pollen and 77 days for silking. The grain needs 55 – 60 days to ripen post pollination.

This breed is highly productive both as is and in crosses with other Mexican corns, showing excellent contribution to yield in low and medium elevation sites.*** Grain production is quite good in Tennessee too, and the plants seemed happy here last summer.

This seed stock was harvested in 2021 and traces back to 150 hand-pollinated plants.

A large chunk of the constituting seed ears.

Also, despite the “Harinoso” (floury / soft) in the name, this collection is more flinty than floury, due to introgression of a Mexican popcorn (Reventador?) decades back before the original seed stock was donated to the seed banks. Successive growouts have likely placed selection pressure on the population to become more flinty over time, favoring the introgression of the harder grain from Reventador.

cited sources:

**Werth, Lindsay C. “Characterization and classification of Native American maize landraces from the Southwestern United States.” https://dr.lib.iastate.edu/entities/publication/01678b96-9dc3-4fb4-8a35-d10e11e94f0b

***J. Crossa, S. Taba, E. J. Wellhausen. “Heterotic Patterns among Mexican Races of Maize.” 1990, Crop Science, Vol. 30, Issue 6, pages 1182-1190.

An important trait: staygreen.

No, that’s not disease that you’re seeing on the Z. Chico (left). Some corns just die down much faster than others post blooming. Breeding plants that remain green for longer seems to help with yield (more photosynthesizing) and stalk quality (less stalk rot).

Disease Photos (2021)

As expected, I had a bunch of diseases this year. Two were new.

Eyespot. I don’t remember this one.
Common Rust. In the 10 years that I’ve grown corn here, it has never been this severe.
Grey Leaf Spot. I haven’t seen this much of it before.
Northern Leaf Spot. Hasn’t been this aggressive since 2014.
Northern Leaf Blight. Severe, as usual.
Severe leaf smut.

Southern Rust was present this year too, but I gotta find a quality photo of it.

One can see why growing corn here is often so difficult. Finding a variety or population that resists EVERYTHING is quite rare.

Adapting Tropical Corn To Long Days

Hey! It’s been a while, but I’m back from the field – with lots of photos.

In this post, I’m gonna show more examples of what happens when one moves around a few alleles from temperate corn into tropical corn.

Pure Amazon (L) vs. Adapted Amazon (Entrela├žado) (R); 90 days to bloom vs. 55 days

The goal is to eliminate the sensitive genetics, while keeping everything else. It’s a whole lot easier to maintain a corn that doesn’t grow to 15 feet and bloom in 90 days, afterall!