Propagation techniques and organic fertilizer supplementation on growth and tuber yield of yacon (Smallanthus sonchifolius)

Organic fertilizers in yacon (Smallanthus sonchifolius) cultivation promotes sustainable agriculture and advances key Sustainable Development Goals (SDGs) by improving soil fertility and yields (SDG 2), reduces synthetic inputs (SDG 12), improves soil health and biodiversity (SDGs 13 and 15), and supports smallholder farmers (SDGs 8 and 10). The study evaluated the effects of different propagation techniques and organic fertilizer supplementation on the growth, yield of Yacon. Two propagation techniques—cuttings and rhizomes—were assessed with five fertilization treatments: fullNPK (50-20-30 kg ha⁻¹), and reduced NPK (25-10-15 kg ha⁻¹) supplemented with vermichar, vermicompost, biochar, or Black Soldier Fly (BSF) frass. Measurements included plant height, branch number, marketable tuber number and weight, yield per hectare. Cuttings significantly increased plant height at 100 and 150 days after planting. While propagation had no significant effect on yield, cuttings with BSF frass consistently showed higher values across indicators. BSF frass significantly increased the marketable tuber number and weight, total yield per hectare (12.82 t ha⁻¹), indicating superior performance. Vermicompost and biochar also improved yield but were less effective than BSF frass. The interaction of propagation and fertilization revealed that the combination of cuttings and BSF frass produced the highest plant height (121.03 cm), yield (12.94 t ha⁻¹). While not statistically significant, trends indicate that organic fertilizers with reduced NPK enhance yield and quality. In conclusion, BSF frass with reduced NPK and cuttings sustainably improve yield while lowering reliance on synthetic fertilizers. published by the International Journal of Agronomy and Agricultural Research | IJAAR