Pillowing in Nursery Seedlings: Meaning, Effects, and Control
What is Pillowing?
Pillowing is a common physiological disorder in nursery seedlings where the roots of young plants grow upwards or outwards instead of growing downwards into the soil properly. This results in the roots bending or coiling near the soil surface, resembling small pillows or cushions — hence the name “pillowing.”
It usually occurs in seedlings raised in containers, polybags, or seedbeds with compacted or poorly aerated soil.
How Pillowing Affects Seedlings in the Nursery?
Pillowing negatively impacts seedling growth and quality in several ways:
- Poor Root Anchorage:
Since roots do not penetrate deeply or properly into the soil, the seedlings have weak anchorage. They are easily uprooted or blown away by wind. - Reduced Nutrient and Water Uptake:
Roots growing near the surface have limited access to soil moisture and nutrients, leading to poor seedling vigor and stunted growth. - Transplanting Shock:
Seedlings with pillowed roots suffer more transplant shock because their root systems are weak and less developed, reducing survival rates after planting. - Root Damage:
When roots bend or coil, they can get damaged during handling or transplantation, causing injury and increasing susceptibility to diseases. - Uneven Growth:
Seedlings affected by pillowing often show uneven or poor growth compared to healthy seedlings.
Causes of Pillowing
- Compacted or Heavy Soil: Poor soil aeration and drainage lead to restricted root growth.
- Shallow or Thin Soil Beds: Roots hit a hard pan or pot bottom and start bending.
- Waterlogging or Excess Moisture: Roots may avoid saturated soil and grow upward.
- Improper Seedling Handling: Rough handling or lifting seedlings before roots establish.
- Insufficient Root Space: Crowded or small containers force roots to grow in unnatural directions.
Control Measures for Pillowing
To prevent and control pillowing, follow these nursery management practices:
- Use Well-Prepared Nursery Beds or Containers:
- Ensure soil is loose, friable, and well-drained.
- Avoid compacted or heavy clay soils; mix sand or organic matter to improve texture.
- Use adequate depth in containers and polybags (at least 15-20 cm) for root growth.
- Maintain Proper Water Management:
- Avoid waterlogging or excess irrigation.
- Water seedlings regularly but do not saturate soil.
- Use well-drained media to prevent stagnant water around roots.
- Adequate Seedling Spacing:
- Avoid overcrowding seedlings in seedbeds or containers.
- Provide enough space for root development.
- Deep Ploughing or Soil Preparation:
- Break hardpans or compacted layers in seedbeds to allow roots to penetrate easily.
- Use Root Pruning or Root Trainers:
- In container nurseries, use air pruning pots or root trainers to encourage downward root growth.
- Proper Handling During Transplanting:
- Lift seedlings carefully without disturbing the root system.
- Avoid lifting seedlings too early before roots are well-established.
- Use Appropriate Containers:
- Use bags or pots of sufficient size and depth.
- Avoid very shallow or narrow containers.
- Regular Monitoring:
- Inspect seedlings regularly to detect early signs of pillowing.
- Replant or correct affected seedlings if possible.
Summary Table on Pillowing
| Aspect | Details |
|---|---|
| Meaning | Roots grow upwards/coiled near soil surface |
| Effects | Poor anchorage, reduced nutrient uptake, transplant shock |
| Causes | Compacted soil, waterlogging, shallow containers |
| Control Measures | Use loose soil, proper irrigation, adequate depth containers, careful handling |
Conclusion
Pillowing is a serious issue affecting the healthy development of nursery seedlings by restricting proper root growth. It leads to poor seedling establishment and lower survival after transplanting. However, with proper nursery bed preparation, soil management, adequate irrigation, and careful handling, pillowing can be effectively controlled, ensuring robust and healthy seedlings for successful horticultural production.