The global interest in quinoa (Chenopodium quinoa Willd.) is rapidly increasing, both as a result of its nutritional qualities but also due to its potential as an alternative crop in regions, such as the Mediterranean and Western Australia, where increasing soil salinity and extended periods of drought are the major constraints on agricultural productivity. However, quinoa originates from the Andean region and the majority of available cultivars are facultative short day plants and exhibit severely reduced, or completely disrupted, seed production under day lengths longer than 12 hours. The inherent photoperiod sensitivity poses a challenge to future success of quinoa in regions outside its centre of origin. The existence of day length neutral quinoa cultivars provide an attractive alternative for cultivation in regions outside the tropical zone, as well as a valuable tool to compare adaptive day length responses in contrasting cultivars. Throughout this study, separate controlled environment experiments, involving contrasting cultivars, were employed to evaluate yield performance and compare leaf level physiological responses to changes in day length and the influence of different light environments. Basic physiological studies of quinoa are needed and can benefit the progress of a more efficient and targeted adaptation approach and development of new cultivars, thus supporting the worldwide expansion of quinoa cultivation.