Seed Treatment And Methods Of Seed Treatment

Seed treatment is a process of application either by mixing or by coating or by soaking in solutions of chemicals or protectants (with fungicidal, insecticidal, bactericidal, nematicidal or biopesticidal properties), nutrients, hormones or growth regulators or subjected to a process of wetting and drying or subjected to reduce, control or repel disease organisms, insects or other pests which attack seeds or seedlings growing there from. Seed treatment also includes control of pests when the seed is in storage and after it has been sown/planted.

The seed treatment is done for the following reasons;

• To protect from seed borne pests and diseases.

• To protect from or repel birds and rodents.

• To supply plant nutrients.

• To inoculate microorganisms.

• To supply growth regulators.

• To supply selective herbicides.

• To break seed dormancy.

• To induce drought tolerance.

• To induce higher germination percentage, early emergence.

• To obtain polyploids (genetic variation) by treating with x-rays, gamma rays and colchicines.

• To facilitate mechanized sowing.

Methods of Seed Treatment

1. Dry treatment: Mixing of seed with powder form of pesticides/nutrients.

2. Wet treatment: Soaking of seed in pesticide/nutrient solutions

3. Slurry treatment: Dipping of seeds/seedlings in slurry. Example–rice seedlings are dipped in phosphate slurry.

4. Pelleting: It is the coating of solid materials in sufficient quantities to make the seeds larger, heavier and to appear uniform in size for sowing with seed drills. Pelleting with pesticides as a protectant against soil organisms, soil pests and as a repellant against birds and rodents.

Pre-treatment of Rice seeds (before sowing)

(a) Dry seed treatment: Mix any one the fungicide at 2 g/kg of seed (Thiram, Captan, Carboxin or Carbendazim). Treat the seeds at least 24 hrs prior to soaking for sprouting. The seeds can be stored for 30 days without any loss in viability.

Treatment of seeds at the time of soaking the seeds f or sprouting

(a) Wet seed treatment: Treat the seeds in Carbendazim or Pyroquilon or Tricyclozole solution at 2g/lit of water for 1 kg of seed. Soak the seeds in the solution for 2 hrs. Drain the solution, sprout the seeds and sow in the nursery bed. It gives protection to the seedlings up to 40 days from seedlings disease such as blast and it is better than dry seed treatment.

(b) Seed treatment with Azospirillum: Three packets (600 g/ha) of Azospirillum culture are to the mixed with sufficient water wherein seeds are soaked over night before sowing in the nursery bed. The bacterial suspension after decanting may be poured over the nursery area itself.

(c) Seed treatment with Pseudomonas fluorescence: Three packets (600 g/ha) of Pseudomonas culture should be added in water wherein seeds are soaked over night before sowing in the nursery bed. It can be mixed with Azospirillum culture, as it is not inhibitory to Azospirillum.