Unleasing the potential of seaweed biostimulants-a comparative evaluation for enhancing saffron (Crocus sativus L.) yield with different corm sizes in the Western Himalayas.

Background: Biostimulants, particularly those derived from seaweeds, are gaining increasing attention in agricultural practices due to their potential to enhance plant growth, productivity, and stress tolerance. Saffron, a high-value crop, faces challenges in yield optimization and environmental sustainability. In this context, the present study aimed to evaluate the effects of minimally processed homogenates (MPHs) of two red seaweed-derived species, Solieria chordalis (C. Agardh) J. Agardh and Gracilaria edulis (S.G. Gmelin) P.C. Silva, on saffron (Crocus sativus L.) growth and corm production. The experiment was conducted during the 2022-2023 growing season and employed a factorial randomized block design with two biostimulants (S. chordalis and G. edulis, both applied at 2.5%) and five corm sizes (C1: 6-8 g, C2: 8.1-10 g, C3: 10.1-12 g, C4: 12.1-14 g, C5: >14 g), replicated four times.

Results: The results indicated that both seaweed treatments and corm sizes significantly affected saffron growth parameters and dry weight. Plants from larger corm sizes (C4 and C5) exhibited significantly greater plant height and leaf length, with C5 (> 14 g) showing the highest values 31.42 cm at 60 days after sowing (DAS) and 47.52 cm at 90 DAS. Additionally, chlorophyll 'a' content was higher in plants treated with S. chordalis and C2 (8.1-10 g) corms, while chlorophyll 'b' was elevated in plants treated with G. edulis and C1 (6-8 g) corms. Treatment combination T10, which involved larger corm sizes, particularly C5, along with the application of G. edulis, produced a higher number of daughter corms with a weight of more than 8 g per corm, suggesting improved corm multiplication. This treatment also aligned with PCA results, where T10 was distinctly positioned in the positive quadrant of both PC1 and PC2, highlighting its strong overall contribution to vegetative growth and corm multiplication.

Conclusion: The study highlights the importance of integrating larger corm sizes with biostimulants to not only boost saffron growth but also increase corm multiplication, a key factor in saffron cultivation. These findings support the application of seaweed biostimulants as a sustainable strategy for enhancing saffron productivity. By promoting plant growth, and increasing corm production, seaweed biostimulants offer an environmentally friendly alternative to the excessive use of synthetic fertilizers, thus contributing to more sustainable saffron cultivation practices.