Effect of Row Spacing on Quinoa ( Chenopodium quinoa ) Growth, Yield, and Grain Quality under a Mediterranean Climate

Quinoa ( Chenopodium quinoa Willd., Amaranthaceae) is an environmental stress-resilient crop of increasing global importance. Sowing density is a critical factor in the quinoa cultivation protocol. We evaluated the row-spacing effect on quinoa growth, yield, and grain quality under Mediterranean conditions. We hypothesized that lower row spacing would reduce quinoa stem diameter and increase yield but may reduce grain quality. Two quinoa accessions were sown in northern Israel with 16, 26, or 80 cm between rows during two consecutive years, in November and January each year. Plant density at harvest ranged from 22 to 260 plants m −2 . Plant height and stem diameter ranged from 77 to 126 and 6.3 to 10.5 cm, respectively. Hay, grain, and straw yield ranged from 2259 to 17,979, 1604 to 4266, and 1212 to 3660 kg DM ha −1 , respectively. Grain protein content (PC) ranged from 5.2 to 14.2 and thousand grain weight (TGW) from 2033 to 3446 mg. Plant density, hay, grain, and straw yield were negatively correlated to row spacing. Stem diameter was positively correlated to row spacing, while there were no correlations between this parameter and plant height, grain PC, or TGW. Results indicated that 16 cm between rows may be optimal, as this produced the greatest yields with no effect on grain quality. However, as it may result in plant lodging, 26 cm row spacing should also be considered. The effects of additional management-related parameters on quinoa production should be examined.