Canola seeds coating with formulations based on sodium alginate, chitosan and Thichoderma harzianum

Abstract

Seed coating technology combined with biopolymers offers an alternative method to reduce environmental contamination. However, when biological agents are incorporated, biopolymers would have diverse properties and effects. This underscores the necessity of exploring the optimal dosages and formulations of biopolymers to ensure the survival of beneficial microorganisms, seed quality, and proper storage. This study aimed to explore the effects of different sodium alginate and chitosan coating formulations on Trichoderma harzianum viability and canola seeds quality. The coating process involved mixing T. harzianum powder with sodium alginate, talc and chitosan in different doses, sequences and formulations. Trichoderma harzianum viability was assessed through colony-forming units per ml over time. Canola seed quality was evaluated by measuring radicle emergence, germination percentage, seedling growth, and field emergence. Sodium alginate, both alone and in combination with talc, improved T. harzianum viability immediately after treatment and during storage. These coatings did not impair seed germination and improved canola root growth. Among the different chitosan formulations, a 1 : 100 ratio in talc improved strain survival and root growth without affecting germination, radicle, and field emergence. Coating canola seeds is a practical alternative to the application of T. harzianum, sodium alginate and talc, as it preserves their viability over time and improves seedling performance. Chitosan formulations in acetic acid should be carefully developed to prevent negative effects on seeds or biological agents.

Keywords

• biopolymers
• field emergence
• germination
• growth
• radicle