Breeding an economically viable functional potato variety with garlic husk biofertilizer for chernozems of Central Asia

This paper presents the results of a three-year interdisciplinary study on the development of a novel potato variety through targeted breeding combined with the application of a biofertilizer derived from garlic husk (Allium sativum L.) processed via bioconversion by Hermetia illucens larvae. Field experiments were conducted on a 0.5 ha experimental plot of typical chernozem soil in northern Kazakhstan. The new variety demonstrated a yield of 38.6 t/ha under biofertilizer application, a 31.4% increase over unfertilized controls. Tubers exhibited significantly improved biochemical profiles, including increased total polyphenols (21.3 mg/100g), flavonoids (26.8 mg/100g), vitamin C (24.1 mg/100g), and antioxidant activity (FRAP 2.34 mmol Fe²⁺/kg), alongside reduced nitrate accumulation (112 mg/kg) and 78% lower wireworm damage compared to standard varieties. From an economic perspective, the biofertilizer system reduced production costs by 21.8% compared to conventional practice, achieving a net profit of USD 3,901 per hectare—36.3% higher than the USD 2,862 per hectare obtained with imported varieties and mineral fertilizers. The USD 60,000 investment in breeding is projected to be recouped within 0.58–1.16 years depending on adoption scale, with an Internal Rate of Return of 62.4% and a Net Present Value of USD 500,072 over five years. The variety enables import substitution of seed potatoes, with estimated annual savings of USD 3.25 million for every 5,000 tons replaced. Molecular analyses revealed upregulation of phenylalanine ammonia-lyase (PAL) and GDP-L-galactose phosphorylase (GGP) expression, downregulation of nitrate transporters (NRT1.1, NRT2.1), and activation of systemic acquired resistance markers (PR1, PR2). The newly developed variety represents the first potato cultivar specifically adapted to a biofertilizer system based on local agricultural waste, contributing to sustainable agriculture, circular economy principles, and economic sovereignty in Central Asian potato production.