Agronomic performance of quinoa (Chenopodium quinoa Willd.) under two moisture regimes in a brazilian savannah soil

Resumo

Sustainable grain production in the Brazilian Savannah (Cerrado), relies on biological diversity and tillage improvement. The present practice of no-tillage, which depends on soil cover, includes few species, i.e., maize, millet, sorghum (Gramineae), soybean and common bean (Leguminosae). Quinoa, the Andean grain crop (Chenopodium quinoa Willd., Chenopodiaceae), has been introduced in the savannah to utilise residual moisture in double cropping, for mulch and grain production. Selected genotypes were grown in autumn, after soybean harvest, in Planaltina, DF, Brazil, located at 15o 36' S and 47o 12' W, elevation of 1,000 m.a.s.l. A randomised complete block experiment, with three replications, was used on an oxisol (Ferralsol, FAO), under residual moisture and supplemental irrigation regimes. Grain yield for, Q18 and Q24, was 2,200 and 1,153 kg ha-1 for respective irrigated and stressed condition. This character was positively associated with plant height and plant cycle. Early maturity genotypes had higher yields under stress than late, with few exceptions, like Q24, yielding 56% of its performance in sufficient water supply. Selection for drought tolerance and vigorous growth, combined to early maturity in main crop, to anticipate sowing, will contribute for commercial cultivation of quinoa in the tropics.