Enhancing productivity and profitability of quinoa through optimization of plant spacing and weeding regimes.

Weeds are a major constraint to quinoa production since no herbicide tolerant variety is available worldwide. This raises the importance of cultural practices for controlling weeds. Optimizing plant spacing and implementing effective weeding practices may help to enhance quinoa productivity and profitability. The objective of current study was to utilize the plant spacing as an alternate option for ensuring effective weed management and profitable quinoa production for the irrigated plains. The effect of planting spacing on weed flora in quinoa was evaluated for two consecutive years (2021–22 and 2022–23). Two weeding regimes (weedy and weed-free) along with three plant spacings viz., 10, 20, and 30 cm were tested using a randomized complete block design in split-plot arrangement with three replications. In the weedy plots, no weeding was done, while in the weed-free plots, manual weeding was performed to keep them weed-free throughout the growing season. Different plant spacing significantly influenced weed biomass and density in quinoa. Narrow spaced plants (10 cm) gave maximum weed suppression as against widely spaced plants (30 cm) and a concomitant yield increase. Medium plant spacing (20 cm) gave maximum grain yield by attaining the optimum plant population under weed-free conditions during both years. Economic analysis also revealed that medium plant spacing with weed-free conditions was beneficial compared to other treatments regarding gross returns, net returns, and benefit-cost ratio. This study highlights that quinoa spacing primarily determined quinoa-weed competition and can be a tool for weed management in this crop. • Weed growth and quinoa yield response to plant spacing and weeding regimes. • Presence of weeds caused biotic stress and led to a severe decline in crop yield. • Narrow plant spacing: better weed control and grain yield under weedy conditions. • Medium plant spacing resulted in higher grain yield under weed-free treatment. • Findings can be used for designing quinoa's integrated weed management package. [ABSTRACT FROM AUTHOR]