Optimising Hybrid Performance

On considère que la culture atteint un stade lorsque 50% des plantes présentent les caractéristiques qui lui correspondent.

Mineral supply

Mineral supply

Weeds

Weeds

Pests

Pests

Water supply

Water supply

  • 1er stade de végétation

    Leaf differentiation and emergence

  • 2ème stade de végétation

    Ovule development and pollination
    Leaf, root, and stalk growth

  • 3ème stade de végétation

    Kernel set
    Grain fill

MID-APRIL|LATE MAY

+/- 80 GDDs, depending on planting date, climate, and soil

Planting/Emergence

  • The first leaf emerges on the soil surface. Seedlings are visible along the row.
Planting/Emergence

Weed control before planting/Weed control before emergence

LATE APRIL | EARLY JUNE

2 - 3 leaves

  • The first leaf has a rounded tip. The seedling lives off the seed reserves.
2 - 3 leaves

Nitrogen: treatments should be split. Adjust rates to the field potential. Split treatments allow nutrient supplies that are in step with the needs of the plant.

Trace minerals: apply Zn and Mn treatments during crop development, if necessary.

1.  Apply broadcast weed control as a complementary measure, on annual grasses and annual dicots.

 

EARLY MAY | EARLY JUNE

4-5 leaves | Seedling “weaning”

  • The seedling feeds off the recently-emerged seminal roots and crown roots.
  • Establishment of the final plant population.
4-5 leaves | Seedling “weaning”

Nitrogen: Treatments should be split. Adjust rates to field potential. Split treatments allow nutrient supplies that are in step with the needs of the plant.

Trace minerals: Treatments during crop development, if necessary.

1. Apply broadcast weed control as a complementary measure, on annual grasses and annual dicots.
2. Postemergence weed control
3. First treatment against perennial weeds

Follow local alerts on slugs, earworm caterpillars, aphids, etc.

EARLY JUNE | LATE JUNE

An average 44 GDDs are needed for each new leaf.

8-10 leaves | Tassel and ear shoot initiation

  • At 50-percent visible leaves (8 leaves in early hybrids and 10 leaves in late hybrids), all leaves are differentiated and the tassel and future ear are initiated. The plant enters its rapid growth phase.
8-10 leaves | Tassel and ear shoot initiation

Nitrogen: Treatments should be split. Adjust rates to field potential. Split treatments allow nutrient supplies that are in step with the needs of the plant.

Trace minerals: Treatments during crop development, if necessary (Zn and Mn).

1. Apply broadcast weed control as a complementary measure, on annual grasses and annual dicots.
2. Postemergence weed control
3. First treatment against perennial weeds

Beginning of moisture stress sensitivity.

MID-JUNE | MID-JULY

12 - 14 leaves

  • Leaves cover the inter-row space. Leaf area index is close to 1 (1 hectare of leaves per cultivated hectare).
12 - 14 leaves

A second – targeted – treatment may eventually be applied on perennial weeds.

Corn borers: follow local alerts.

Begin irrigating based on local forecasts or tensiometer readings

EARLY JULY | MID-JULY

220 GDDs before female flowering

Tassel is visible in the whorl

  •  The tassel emerges from the leaf whorl. The silks begin to elongate. The number of ovules per row is set.
  •  The number of potential ears is set.
  •  The number of ovules which can be pollinated is set.
Tassel is visible in the whorl

Apply nitrogen treatments in case of fertigation.

Corn borers: follow agronomic alerts.

Begin irrigating based on local forecasts or tensiometer readings.

MID-JULY | MID-AUGUST

• Early: 825 to 875 GDDs • Semi-early, flint-dent: 875 to 925 GDDs • Semi-early, dent: 925 to 980 GDDs • Semi-late: 975 to 1000 GDDs • Late: 1000 to 1050 GDDs

Female flowering

  •  The silks emerge from the ear. The tassel produces pollen. The ovules are pollinated. The leaves have finished growing. The leaf area index is at its maximum.
Female flowering

Apply nitrogen treatments in case of fertigation.

Cruising speed: rates and frequency should be adjusted to soil and climate. Follow local forecasts.

MID-AUGUST/EARLY SEPTEMBER

250 dj après floraison femelle

Kernel abortion threshold

  • The cells of albumin (future reservoir of starch) multiply during the three weeks of latent stage which follow the pollination. The increase in kernel weight is low during this period, when the final number of kernels is established. The plant reaches its maximum height.
    The dry matter that has been produced is stored in the stalk. The vegetative portion of the plant reaches its maximum weight.
Kernel abortion threshold

Cruising speed: rates and frequency should be adjusted to the soil and climate. Follow local forecasts.

END-AUGUST/MID-SEPTEMBER

20-24 days needed at the end of this stage, per point of additional dry matter.

Emergence of lentille vitreuse (in vitreous and vitreous-dented varieties) • Emergence of the depression at the top of the kernel (in dented varieties)

  • Dry matter accumulates fast inside the kernel. The starch texture evolves, going from milk to wax, then floury and vitreous. The early development of vitreous starch inside the kernel of flinty and flinty-dented varieties indicates a D.M. rate of 25 to 27 percent.
Emergence of lentille vitreuse (in vitreous and vitreous-dented varieties) • Emergence of the depression at the top of the kernel (in dented varieties)

Follow the local forecasts to better determine when to end irrigation. Consider the date, the crop stage, and the soil water reserve.

MID-SEPTEMBER/END SEPTEMBER

600 to 675 dds after the female flowering.

50 percent kernel moisture

  • Kernel growth slows down. This stage is characterized by one third of milk starch in the albumen.
  • At 50 percent kernel moisture, the DM of the whole plant is at about 32 percent.
50 percent kernel moisture

Follow the local forecasts to decide when to stop irrigating. Factors to take into account should include the date, the crop stage, and the soil water reserve.

MID-SEPTEMBER/EARLY OCTOBER

• 640 to 700 dds after the female flowering. • 18 dds needed to decrease kernel moisture by 1 percent.

45 percent kernel moisture

  • The kernel reaches 75-80 percent of its maximum weight.
  • The stalk and leaf DM supports the growth of the kernels. The leaf index decreases fast.
  • The whole plant yield is maximum.

Feed harvest between 28 and 35 percent DM/whole plant.

45 percent kernel moisture
MID-OCTOBER/END OCTOBER

850 to 950 dds after female flowering, depending on the earliness.

32 percent kernel moisture

  • The maize plant has reached physiological maturity. Kernel weight is at its maximum. The black layer appears at the kernel base, indicating that the nutrient transfer is over. Starch is either completely floury or flinty. The plant has a dried-out aspect.

Grain harvest – if possible – after 35 percent moisture, or earlier for maize used for . 

32 percent kernel moisture

Fine chopping of crop residues by way of preventive corn borer control.