Optimizing Protein-Rich Young Vegetative Quinoa (Chenopodium quinoa) Growth: Effects of Inter-Row Spacing and Genotype in Mediterranean Summer Cultivation

Young vegetative quinoa (YVQ) has gained attention as a high-protein leafy crop with potential for cultivation in Mediterranean and semiarid regions. We investigated the effects of inter-row spacing and genotype on YVQ fresh and dry matter (DM) yield, protein content (PC), and protein yield during summer cultivation in northern Israel in two field experiments over two consecutive years (2020–2021). We hypothesized that row spacing and genotypic differences would significantly impact yield and PC. Inter-row spacing significantly affected plant density, ranging from 55–366 plants m–2. Fresh and DM yields ranged from 4957–28,469 kg ha–1 and 661–3662 kg DM ha–1, respectively. PC ranged from 20.5%–26.6% and was not significantly influenced by row spacing. Total protein yield ranged from 147–884 kg ha–1. Among genotypes, no significant differences were observed in fresh or dry biomass, PC, or protein yield (7477–17,776 kg ha–1, 1122–2199 kg DM ha–1, 21.2%–26.5%, 260–579 kg ha–1, respectively), suggesting that genetic variation among the tested accessions had minimal influence under the given growing conditions. Amino acid analysis confirmed the presence of all essential amino acids, fulfilling over 30% of the recommended daily intake per 100 g DM. These findings highlight YVQ as a promising, sustainable, and protein-rich leafy crop for Mediterranean agriculture. Further research should explore multiharvest potential, mechanical weeding, and optimized agronomic practices for commercial-scale production.