What is relative maturity in corn?

The term “Relative Maturity” is often used when discussing corn and soybean seed. It is best defined as a criteria or process to compare or group hybrids and varieties based on physiological maturity. Secondly, different seed companies use different formulas to rank their hybrids.

How do you calculate corn maturity?

Corn growth stages can be estimated using corn growing degree days (GDD) accumulated daily from the date of planting. Corn GDD are calculated by taking the maximum daily temperature plus the minimum daily temperature to determine the average temperature in a 24-hour period.

What is the maturing period of maize?

between 110-120 days
Matures between 110-120 days; attains a plant height of 180-200 cm. Quality Protein Maize (QPM).

How many GDD does corn need?

Based on research in Iowa, corn typically required 90 to 120 Growing Degree Days (GDD) from planting to emergence (See Corn Growth & Development). This range assumes adequate soil moisture and will vary with planting depth, tillage system, and residue cover.

What is black layer in corn?

Black layer is the stage in corn development at which kernel growth ceases and maximum kernel dry weight is achieved (also referred to as “physiological maturity”). A killing fall frost prior to physiological maturity can cause premature leaf death or whole plant death.

What are the stages of corn growth?

There are 4 distinct stages of growing corn: planting, germination, vegetative, and reproductive.

How long does it take corn to grow?

Corn typically requires 90 to 120 Growing Degree Days (GDD) from planting to emergence.

How many months do maize take?

Corn requires from 60 to 100 days to reach harvest depending on the variety and warm weather. Corn is ready for harvest when ears turn dark green, silks turn brown, and kernels are soft and plump; squeeze a kernel and the juice will be milky, not clear.

In which month does maize grow?

It is a Kharif crop and thus it grows best in the rainy season. In India, the rainy season starts in the month of June and ends in the month of September. Thus, maize is grown from June to September in India.

Does corn only grow at night?

Any corn farmer will tell you, during growing season, corn shoots up suddenly and quickly, but only at night. If you observe it during the day, it seems like nothing is happening. You go to sleep, and in the morning, the cornfield is unrecognizable from last night taller. Corn grows in spurts, night after night.

How long does it take corn to emerge?

If the soil temperature is averaging 50 to 55 F (10-12.8 C) at the time of planting, corn may take three weeks to emerge. Temperatures averaging 60 F (15.6 C), may have emergence in 10 days to 12 days.

What’s the moisture content of corn at maturity?

Grain moisture content at the onset of physiological maturity typically occurs within the range of 25 to 35 percent, though black layer can occur at grain moistures as wet as 40 percent. Grain moisture at physiological maturity varies year to year depending on growing conditions and can vary hybrid to hybrid.

When do corn kernels reach their maximum weight?

Physiological Maturity (R6) About 55 to 65 days after silking, kernel dry weight usually reaches its maximum and kernels are said to be physiologically mature and safe from frost. Physiological maturity occurs shortly after the kernel milk line disappears and just before the kernel black layer forms at the tip of the kernels.

What makes a corn seed black in maturity?

In early seed development, a black layer forms in a region of cells several layers thick between the endosperm base of the kernel and the vascular area of the pedicel. Near physiological maturity, these cells compress into a dense layer, which appears visibly black.

How are corn maturity ratings related to GDUs?

Fig. 2. Relationship between company ratings for growing degree units (GDUs) from planting to kernel black layer with company ratings for relative hybrid maturity (CRMs). Adapted from data listed in “Characteristic Ratings of Pioneer® brand Corn Hybrids for 2011”, Pioneer Hi-Bred, Int’l.