Early Canopy Development and Light Interception
Canopy development is crucial to crop growth rate. In fact, it is generally believed that the primary factor limiting crop yield is solar radiation. Soybeans only convert 5% of solar radiation into carbohydrates. In intensive agronomic management systems where moderate to severe stress is avoided or prevented, yield is proportional to the amount of radiation intercepted.
There are many benefits of managing soybeans for early canopy development, including:
- Canopy photosynthesis increases.
- The number of main-stem nodes and biomass increases.
NOTE: A new soybean node is produced approximately every 4 days after plants reach V1. This 4-day cycle is relatively insensitive to seasonal temperature or rainfall.
- Your crop has the potential to flower earlier and therefore have a longer reproductive period.
- Soil moisture is conserved for critical reproductive periods.
Any sunlight that reaches the soil surface is wasted energy. It evaporates soil moisture or heats up the soil surface, and does not contribute to crop growth.
Tips: Planning for Optimal Growth Rate
You may be able to improve your crop growth rate by promoting earlier canopy development and increasing light interception. Here's how:
- Plant early.
- Plant in narrow rows.
- Choose the appropriate seeding rate.
- Use Acceleron® Seed Treatment Products.
Scouting Practices (VE-VC)
When scouting during early growth stages, follow these steps to conduct a thorough check on the health of your young soybean crop.
- Determine the extent and severity of any problem. Is it throughout the field, or spotty and localized?
- If emergence has just occurred, check carefully to be sure no more seed is sprouted and ready to emerge.
- Take accurate stand counts and calculate:
Stand Achieved (%) = (# plants established/# seeds planted) x 100
- If replanting is necessary, identify the cause for the poor emergence and take steps to fix the situation.
- If stand is uneven or there are skips down the row, dig to find the planted seed and its distribution.
The following table lists general symptoms of the seed and possible cause(s).
||1. Improper planter adjustments worn parts, clogged spout, or empty box or tank, wrong plates, disks or drum, or excess or wrong seed treatment.
2. Digging and partly-eaten kernels by birds and/or rodents.
|Normal seed appearance but not swelled
||1. Cold or dry soil.
2. Poor seed-soil contact.
|Normal seed appearance swelled but no sprout
||1. Cold, dry, wet soil.
2. phytotoxic pesticide or too much fertilizer close to the seed.
3. Needs more time for emergence to occur.
|Seed dead, rotted
||1. Seed rots, seedling blights, or fertilizer injury.
2. Dead seeds planted.
3. Cold, dry, wet or crusted soil.
|Cotyledons fail to emerge
||1. Crusted or cold soil.
2. Seed planted greater than 2" deep.
3. Injured seed during handling and planting.
|Slow uneven emergence
||1. Injured seed due to improper planter operation.
2. Seed planted too deep.
3. Unfavorable soil conditions.
|Cotyledons and/or growing point damaged
||1. Insect (bean leaf beetle, seedcorn maggot, or wireworms) injury.
2. Injury due to rodent, livestock, or wildlife feeding.
|Seedlings pulled or dug up, seeds eaten
||1. Bird or rodent damage.
|Slow, uneven plant growth
||1. Cold, dry, wet or compacted soil.
2. Herbicide carryover or stress.
3. Nematodes attacking roots.
4. Non-uniform planting depth.
||1. Nutrient deficiency.
2. Water logged, cold, or compacted soil may cause nutrient deficiency.
3. Nematodes attacking roots.
4. Wind damage.
5. Frost or freeze damage.
6. High soil pH.
|Leaves puckered, may be wilted
2. Insects attacking roots or stem.
2. Nematodes attacking roots.
4. Chemical injury.
|Shredded leaves or eaten plants
||1. Wind or hail damage.
2. Insect feedings or livestock or wildlife grazing.
|Leaves spotted, dead, or otherwise injured
||1. Wind damage.
2. Nutrient deficiency.
3. Insect and/or disease issues.
4. Sunscald or cold.
5. Fertilizer or herbicide injury.
|Plants wilt and die suddenly
||1. Damage due to wind, lightning, or water logged soil.
2. Disease (fungal seedling blights).
3. Herbicide injury.
|Inhibited root development or malformed roots
||1. Nematode activity.
2. Root rot diseases, insect feedings, or herbicide injury.
|Hypocotyl thickened with limited, stubby roots
||1. Herbicide injury.
2. Soil compaction.
3. Disease — water soaked lesion (Pythium or Phytophthora) or dry lesion (Rhizoctonia or Fusarium).
Minimize Stress from Inadequate Moisture
Moisture stress can have a significant impact on yield. It affects different parts of your crop during different stages.
- Vegetative growth stage: Decreases your crop's growth rate, the number of nodes per plant, and canopy development.
- Flowering: Decrease the number of flowers, pods and seeds per pod.
- Early pod formation: Impacts the number of pods and seeds produced.
That's why it's crucial to provide adequate moisture during critical reproductive stages. Follow these tips:
- Conserve soil moisture through early canopy development
- Irrigate in a timely fashion
- Implement a consistent intensive management approach rather than choosing 1 or 2 of the individual components.
Scout Early for Weeds
Scout your fields early to avoid putting your yields at risk. Learn more about potential loss from the three worst weeds, and how to identify them.