ABSTRACT
Use of Si-based fertilizer significantly improves the performance of ‘Sanren’ botanical seed-derived shallot

Arlyna Budi Pustika1, Afif Farhan Yustyanto2, Sudarmaji1*, Setyorini Widyayanti1, Kristamtini1, Bambang Nuryanto1, Ani Mugiasih1, Sugeng Widodo3, Joko Pramono4, Baswarsiati4, Lia Hadiawati1, Endah Budi Irawati2, Muhammad Prama Yufdy4, and Stephen M. Harper5
 
Shallots (Allium cepa L. var. aggregatum G. Don) are extensively cultivated in Indonesia and exhibit significant market importance. Planting of botanical seed (true shallot seed, TSS) is a promising alternative to seed-bulbs due to increased productivity. However, its implementation at the farmer level needs to be optimized. The TSS from three cultivars with different Si fertilization treatments was tested. The trial used a randomized complete block design (RCBD) with three shallot cultivars (Sanren, Lokananta, and Merdeka) and Si concentrations (0, 5, and 10 mL L-1). Significant interactions (p < 0.05) were seen in Si content, cuticle thickness, plant height, leaf count, tillers, and bulb diameter. Si absorption was highest in ‘Sanren’ treated with 10 mL L1 Si (5.39%), leading to a 121% increase in leaf cuticle thickness (14.10 µm) compared to the control (6.36 µm). Si increased photosynthesis and growth. In ‘Sanren’, leaf number increased from 13.94 (0 mL L1) to 29.81 (10 mL L1) and tiller number from 3.38 to 4.94. With 10 mL L1 Si, yields improved: Bulb number increased from 4.50 to 7.38 per plant, and bulb diameter increased from 2.31 to 2.86 cm. Si treatment raised harvest index from 0.78 to 0.88 across cultivars but extended harvest age by 1.5-6.0 d (62-68 DAP). The principal component analysis showed higher Si absorption lowered leaf Pb, Cu, and Cd. Adding 10 mL L1 Si fertilizer to ‘Sanren’ increased growth and yield by 30%-70%, highlighting the viability of using TSS in shallot farming.
Keywords: Allium cepa var. aggregatum, Lokananta, Merdeka, Sanren, shallot, silica fertilizer, silicon, true shallot seed.
1National Research and Innovation Agency of Indonesia (BRIN), Research Center for Food Crops, Cibinong Bogor, Indonesia.
2Universitas Pembangunan Nasional Veteran Yogyakarta, Faculty of Agriculture, Yogyakarta, Indonesia.
3National Research and Innovation Agency of Indonesia (BRIN), Research Center for Behavioral and Circular Economics, Jakarta, Indonesia.
4National Research and Innovation Agency of Indonesia (BRIN), Research Center for Horticulture, Cibinong Bogor, Indonesia.
5The University of Queensland, School of Agriculture and Food Sustainability, Queensland, Australia.
*Corresponding author (suda019@brin.go.id)