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Brisbane Australia

From my understanding most South American maize is day length sensitive, is it once light goes below 12 hours that triggers this or is it more relative to shortening days, or something in between and dependent on species?
So many questions hahha any opinions or links to articles would be much appreciated.

2/18/2014 8:20:18 PM

Anamosa, IA BPIowegian@aol.com

Corn farmers here in Iowa are generally concerned about what they call degree days. It takes into account the time that the plant has been growing and the temperature. Cool early weather usually means slower growth, later tasseling and later maturity. You might want to check the Iowa State University Extension website for information on corn. But it will be related to crop production and not giants.

2/18/2014 10:28:23 PM

Brisbane Australia

thanks for the reply. I'll look that up and also have a look at the Australian equivalent.

2/18/2014 10:34:23 PM

Bethlehem CT

HI Stillman I just did a quick google search on corn's response to daylength. It is quite an interesting topic. It seems that corn has considerable genetic diversity. Because of this, different regional varieties respond differently to day length. The tropical corn varieties from central and South America tend to tassel under shorter day lengths. Thus when they are grown up north under long days the corns flowering is delayed and these types can attain great height. Modern corn varieties that were bred in the temperate regions of the globe are more daylength neutral.
Height of the daylength neutral types is more affected by other factors like temperature. ( Iowegian stated this) Plant shading is another factor. (When corn plants compete they are forced to grow taller in order to get more sunlight. ) I have seen pictures of the world record holder's corn plants from the 1940's ,he used an elaborate method to shade the corns growing point. (Meristem) Other factors that affect corn's height are of course water and nutrient availablity. Stressors such as heavy constant winds can also cause stunting in plants.

2/19/2014 8:12:16 AM

http://kal.stparchive.com/Archive/KAL/KAL01272000p26.jpg

2/19/2014 9:38:20 AM

Brisbane Australia

thanks for the information and the great article .I think as they are Marodo maize and I have never grown them here before I will just have to see how they go, I think October/ November plant out is ideal in my climate that's mid to late spring that allows them the heat of summer to put on some size. and days don't start to shorten until the end of December.

2/19/2014 2:45:47 PM