Optimal planting date, row width, and critical weed-free period for grain amaranth and quinoa grown in Ontario, Canada

Abstract

The popularity of grain amaranth and quinoa is growing in Ontario, increasing the interest in their cultivation. Two experiments were conducted in southern Ontario in 2013 and 2014 to evaluate optimal planting date (every two weeks from early May to late July), row width (38 or 75 cm), and critical weed-free period (the component of the critical period of weed control that defines the number of days that the crop must remain weed-free to prevent yield loss) in each crop. Grain amaranth and quinoa both reached physiological maturity and produced yields when planting dates ranged from mid-May to late-June. When either crop was seeded in July, yields decreased by more than 50% and the crop did not always reach maturity before the first frost. While row width did not have an impact on yield, it is advisable to grow the crops in wider rows (75 cm) to facilitate weed control early in the growing season (up to 30 d after emergence (DAE)). The critical weed-free period was 24 and 16 DAE for grain amaranth and quinoa, respectively, after which yields were maintained at 95% of the weed-free control. Based on these data, both crops could easily be integrated into the normal cropping rotations found in southern Ontario.Key words: critical weed-free period, row width, planting date, Amaranthus hypochondriacus L, Chenopodium quinoa Willd.Résumé : La popularité grandissante de l'amaranthe et du quinoa en Ontario accentue l'intérêt pour leur culture. En 2013 et 2014, les auteurs ont réalisé deux expériences dans le sud de la province en vue d'établir la meilleure date pour les semis (aux deux semaines, de mai à la fin de juillet), l'écartement idéal des rangs (38 ou 75 cm), et la période cruciale durant laquelle on doit combattre les mauvaises herbes (nombre de jours pendant lesquels la culture ne doit pas subir la concurrence des adventices afin qu'il n'y ait pas baisse du rendement) pour chacune des deux cultures. L'amaranthe et le quinoa parviennent à leur maturité physiologique et produisent des graines lorsqu'on les sème entre la mi-mai et la fin de juin. Des semis en juillet réduisent le rendement de moitié, et la culture ne parvient pas toujours à maturité avant les premières gelées. Bien que l'écartement des rangs n'ait aucun impact sur le rendement, on préconise des rangs plus distants (75 cm) pour faciliter le désherbage au début de la période végétative (jusqu'à 30 jours après la levée). La période cruciale durant laquelle on doit lutter contre les mauvaises herbes correspond à 24 jours après la levée pour l'amaranthe et à 16 jours pour le quinoa. Par la suite, le rendement demeure à 95 % de celui relevé pour la parcelle témoin désherbée. Selon ces résultats, on estime que les deux cultures pourraient facilement s'intégrer aux assolements usuels pratiqués dans le sud de l'Ontario. [Traduit par la Rédaction] Mots-clés : ériode de désherbage cruciale, écartement des rangs, date des semis, Amaranthus hypochondriacus L., Chenopodium quinoa Willd.

Spectral Reflectance Indices and Physiological Parameters in Quinoa under Contrasting Irrigation Regimes

“…On the other hand, our results showed that irrigation is not essential in western Washington (Mount Vernon), where quinoa genotypes performed equally or better in rainfed conditions. However, sowing date also plays an important role involving other factors such as length of growing season, weather temperature, radiations, weed pressure, pests, and diseases (Pulvento et al, 2010; Hirich et al, 2014; Isobe et al, 2016; Nurse et al, 2016). Curiously, we expected the highest grain yield in Chimacum 2016; however, the yield was quite low.…”

Seed yield of two new quinoa (Chenopodium quinoa Willd.) breeding lines as affected by sowing date in Central Italy

“…Before reaching a definitive decision on the suitability of 'DISPAA-Q42', further experimentation is required to determine the performance in different environments and sowing densities. Based on small-scale experiments conducted this year (unpublished results) and from the literature (Risi and Galaway, 1991;Nurse et al, 2016), the above mentioned agronomic aspects significantly influence the date of maturation and seed production. Bertero H. D. (2003).…”

How Do Intensification Practices Affect Weed Management and Yield in Quinoa (Chenopodium quinoa Willd) Crop?

“…Strategoskaia, CC r )] and a no cover soil (CC 0 ); (2) two soil tillage for preparing the quinoa sowing bed-conventional soil tillage in the 0-20 cm soil profile based on moldboard ploughing (CT) and no-tilled soil (ZT); (3) three herbicide rates of post-emergence herbicide-no application (H 0 ), 75% recommended rate (H 75 ), and 100% recommended rate (H 100 ). In the H 0 treatment, hand weeding was carried out 30 days after quinoa sowing to avoid higher yield losses as observed in previous study [8], then weeds were left to grow until crop harvesting. A split-split plot design was adopted, where the winter soil management, soil tillage, and herbicide rate were the main factor, the split factor, and the split-split factor, respectively.…”