How long does maize take to fully grow and be harvested?
How long does the process take from the of the plant growing to the day that you harvest it?
Growing Degree Days or (CCD) and not 24 hour cycles determine how long it takes maize to mature. Corn grows between the temperatures of 50F and 86F. Above and below these temperatures the plant doesn't do much growing if anything. These temperatures are the basis of growth calculation. To calculate a GGD take the high and low temperature of the day. For example 47F and 55F. Ignore the 47F and call it 50F. Take the lower 50 and upper 55 and add them together for a total of 105F . Divide by 2 and get 52. Take your base of 50 and subtract from 52 = 2 + degrees. You had 2 growing degree days. Now in midsummer the high and low daily temperatures are 72 and 93F. 93 is above the optimum growing range of 86F. For the daily CCD use 86 and 72 as your base numbers. Add them together and you get 158. Using the formula, GGD = High temp = Low temp / 2, your trasposition would read GGD = 86 +72 divided by 2 -50 .. Or, 158/2-50 or, 79-50 orfinally 29 GGD. Different hybrids and types of corn need different GDD for maturation. 1360 is a common correlation for maturity. this is usually from leaf break to maturation.
However , each seed manufacturer will have their own chart. Make sure they are using the low of 50 and high of 86 or the 50/86 calculations. If not, they will be glad to help you on your calculations. Some states, like Ohio, make the GGD on a daily basis readily available. You can do it yourself with a high low thermometer to find a particular GGD for a given day. If it takes 1360 GGDs you know now how to calculate using daily average charts for your area to make a good estimation of how many real days in comparison to GGD days it will take for your corn to be ready for harvest. Insect growth follows CCD also. The corn borer has a maturation cycle of 207 CCD days. Corn's fifth leaf day is the same . A farmer looking at his corn and seeing the fifth leaf knows it's time to spray for core borers. Here in Northern Indianq, my red Raspberries summer ripen and the Japanese beetles emerge on the same day.
To make it simple, it takes between 3 months to 5 months. It depends on the cultivars (varieties), climate and altitude. For eg you have fast growing types that can be eaten after 2 months and 1/2. But you have also local varieties that need 5 months (high altitude corn).