The definition of Seed pelleting is a precision planting technique, that involves enveloping a seed with a small amount of inert material, forming a globular unit of standard size, making it easier to plant with precision.
The objective of seed pelleting
- Pelleted seeds are seeds that have been coated and transformed into small, tablet-like structures, possibly containing polymers, pesticides, fungicide natural materials, colorants, or other helpful additives.
- Seed pelleting is to achieve accurate planting, while also enjoying the benefits of improved seed establishment and higher crop productivity.
STEPS IN SEED PELLETING
The three basic steps involved in seed pelleting are stated as
- Stamping: Seeds are evenly coated with adhesive incorrect quantity
- Coating: Next, a sprinkle of filler materials is added to the coated seeds
- Rolling: Seeds are gently rolled over the filler material for effective and uniform coating
MATERIALS NEEDED FOR SEED PELLETING
Adhesive
Materials work efficiently to adhere to the seeds without causing any breakage and comely used adhesive materials are gum arabic, methylcellulose, plastic rexins, polyvinyl acetate, methyl ethyl cellulose, gelatin, casein, etc.
Characteristics of adhesive
- The coating should have a porous structure, allowing air to circulate freely to the seed.
- For the best results in each application, the adhesive coating should have appropriate viscosity.
- The coating should be designed to weaken or break down upon contact with soil moisture, ensuring a smooth start for the seeds.
- Materials that is completely non-toxic.
Filler materials
The filler materials chosen for pelleting should be beneficial and harmless for seeds and rhizosphere.
- Among the commonly used filler materials for pelleting are Rhizobia, lime, gypsum, dolomite, and rock phosphate are prevalent, while other alternatives like peat, poultry manure, moss, and mucilage also used.
- The filler material also acts as a valuable nutrient source, contributing to improved root growth for the plants.
- For low-cost investment and environmental benefits, botanic leaf powder like neem, tamarind, Prosopis, etc are used as filler materials.
Characters of filler materials
- Material to have a porous structure, enabling the free flow of air.
- It should be non-toxic
- Easily soluble in water
- Friendly to both seed, adhesive, and environment
- Low cost
TYPES OF SEED PELLETING
The pelleting is grouped into different types based on the ingredients used for pelleting.
| Types of Pelleting | Ingredients for Pelleting |
| Inoculant pelleting | Biofertilizer viz, Rhizobium, Phosphobacteria, Azospirillum, Azatobactor, Vesicular Arbuscular, Mychorhizae, Azophos |
| Protective pelleting | Biocontrol agents like Pseudomonas, Trichodermma, Rhizobacteria, Bacillus, Streptomyces and insecticides and fungicides |
| Herbicide pelleting | Filler antitode or absorbent coating. Herbicide antitode like 1,8 napthalic anhydride (NA) |
| Nutrient pelleting | Coating with micro and macronutrients namely ZnSO4, FeSO4, CuSO4, KCl, borax, diammonium phosphate (DAP) and other salts suitable for each crop. |
| Hydrophilic coating (Water stress condition) | Starch graft polymers, magnesium carbonate |
| Oxygen supplier coating (Flooded condition) | Peroxides of zinc and calcium |
| Organic pelleting | Leaf powders ( arappu, pungam, acacias) and rhizome powders ( turmeric, Acorus) |
Inoculant pelleting
In the process of seed pelleting, beneficial bio-fertilizers such as Rhizobia, Phosphobacteria, Azospirillum, Azotobacter, Azophos, etc., are utilized, which enhance the activity of rhizosphere microorganisms and aid in nitrogen fixation.
Protective pelleting
- Foliar application of biocontrols, such as Bacillus thuringiensis, has been a common practice for several years. However, the use of seed-applied biocontrols has been relatively limited.
- These seed-applied biocontrol agents, including Rhizobacteria bataticola, Trichoderma harzianum, Bacillus spp, Streptomyces spp, and Pseudomonas spp, offer effective disease control.
Fertilizer pelleting
The application of lime pelleting has been successful in mitigating problems caused by acid soil and fertilizer.
Herbicide protectant pelleting
Herbicides like 1,8-naphthalic anhydride and similar compounds have been identified as excellent options for seed pelleting. These chemicals act as protectors, offering valuable physical protection to the seeds against the harmful effects of herbicides.
Pesticide pelleting
It is most successful in onion seeds; the seeds are pelleted with fungicides like thiram and carboxin, along with an insecticide.
Slow-release chemicals pelleting
- This method offers a fantastic means of delivering essential nutrients and agricultural chemicals to plants.
- Caution is necessary due to the rates at which these substances are applied and their proximity to the seeds. If not handled carefully, these chemicals could pose a risk of toxicity to the germinating seeds.
Hydrophilic and hydrophobic pelleting
Applying a hydrophobic polymer coating, such as Vinamul 3650, proves to be the best technique for soybean seeds. This coating plays a main role in controlling the rate of water uptake in physically dormant seeds, which leads to a reduction in imbibition damage and significantly enhances seed emergence.
Also check out Seed Dormancy, type of dormancy, causes, method of breaking dormancy, advantages, and disadvantages.
Oxygen supplier pelleting
Polymer coatings can help slow down imbibition rates when planting seeds in wet soil, and seed coatings containing peroxide compounds can supply oxygen to seeds under anoxic soil conditions.
Nutrient pelleting
Micro and macronutrients through seed pelleting is not only boost germination and seedling growth but also minimize nutrient availability to weed species, thus preventing nutrient wastage.
PROCEDURE OF SEED PELLETING
- The seeds are gently introduced into a coating drum or pan that resembles a cement mixer.
- As the drum rotates, a gentle spray of water is over the seeds, and then the adhesives and pelleting materials are added
- Each turn of the drum gradually increases the size of the pellet. Longer rotations and more pelleting materials result in larger and rounder pellets, ensuring their quality.
- At the end, a binder is introduced, which hardens the outer layer of the pellet, reducing dust production during handling, shipping, and planting, making everything more convenient.
- Once the pelleting process is then go for seed drying.
ADVANTAGES OF SEED PELLETING
- Seed pelleting helps in increasing the size and weight of small seeds, thus enhancing precision planting and it also helps uniform seedling emergence in the field or in tray.
- Uniform size and shape, along with sufficient weight, make mechanical separation a breeze and ensure a smooth, effortless flow during planting operations.
- It helps in cutting the thinning operation and reduces the seed rate.
- Pelleting helps supply growth regulators and micronutrients
- Provide a protective shield for each seedling, from fungi or insects.
- Saving Fertilizers or chemicals applied to the soil.
- Uniform crop stand
DISADVANTAGES OF SEED PELLETING
- A pelleted seed has higher costs and more weight compared to non-pelleted seeds.
- Pelleted seeds require more moisture for seed germination.
- Pelleting operations are carried out by trained people and need more labor.
- Pelleted seed may act as a barrier to oxygen diffusion thus affecting the seed germination.
- Delay in the field emergence of seeds, at lower moisture level.
FAQ
What is seed pelleting?
Seed is mixed with pelleting filler materials which help increase size for easy handling and weight of small seeds, thus enhanced for precision planting and it also helps uniform seedling emergence in the field.
Seed pelleting suitable for which crops?
High-value, small-seeded crops like onion, lettuce, carrot, tobacco, and tomato.
Seed pelleting companies?
Many seed companies like Incotec India Pvt Ltd etc are doing seed pelleting mainly in high-value vegetable crops.
Planting pelleted petunia seeds?
Pelleted petunia seeds coated with a layer of inert material, often clay-based, to make them easier to handle, sowing, germination, disease Protection, and space during planting.
How long do pelleted seeds lose?
It mainly depends on storage conditions, pelleted seeds are stored in a cool and dry environment condition. Because moisture can lead to mold or seed deterioration.
Seed pelleting materials?
Filler materials like clay, limestone, Vermiculate, Tamarind leaf powder, etc
Adhesive materials like Gum Arabic, Gelatin, Methylcellulose etc
Are pelleted seeds organic?
Yes, you can pellet the seed with organic pelleting materials like Leaf powders ( arappu, pungam, acacias) and rhizome powders ( turmeric, Acorus).
Pelleted vegetable seeds
Pelleting can be practiced in small-sized seeded vegetables like carrots, onions, tomato, chilli, etc.
Which seed germinates faster Pelleted seed or Polymer treated seeds
Pelleted seeds germinate fast, but you should take care of the storage condition and seed viability of pelleted seeds. Pelleted seeds are treated with nutrients that help germinate faster as compared to polymer-treated seeds.
Pelleted seeds India
In India, many seed companies are doing pelleting like Incotech, etc.
Pelleted seed viability period
Pelleted seeds have less viability as compared to non-pelleted seeds or polymer-treated seeds because pelleted seeds have more moisture content as compared to polymer-treated seeds.
