Title:	Quinoa: a potential drought resistant crop for the Brazilian savannah.
Authors:	JACOBSEN, S-E. NUÑEZ, N. SPEHAR, C. R. JENSEN, C. R.
Affiliation:	SVEN-ERIK JACOBSEN, CENTRO INTERNACIONAL DE LA PAPA; NIVARDO NUÑEZ, THE ROYAL VETERINARY AND AGRICULTURAL UNIVERSITY; CARLOS ROBERTO SPEHAR, CPAC; CHRISTIAN R. JENSEN, THE ROYAL VETERINARY AND AGRICULTURAL UNIVERSITY.
Date Issued:	1998
Citation:	In: CONFERÊNCIA INTERNACIONAL DA AGRICULTURA SUSTENTÁVEL EM REGIÕES MONTANHOSAS TROPICAIS E SUBTROPICAIS COM ESPECIAL REFERÊNCIA PARA A AMÉRICA LATINA-SATHLA, 1998, Rio de Janeiro. Anais... Rio de Janeiro: Instituto Nacional de Tecnologia, 1998.
Pages:	5 p.
Description:	Quinoa (Chenopodium quinoa Willd.), a food crop of high quality protein and high in vitamins and minerals, has been grown in the Andean region for thousands of years. It has a pronounced resistance to the main adverse abiotic factors affecting crop production under the harsh conditions of the high Andes: drought, cold, and saline soils. All drought mediating mechanisms, including drought escape, drought tolerance and drought avoidance, are found in the species, although not all mechanisms are present in all genotypes. Quinoa escapes drought principally through early maturity, an important trait in areas where drought risk is likely toward the end of the growing season (terminal drought). Quinoa may tolerate drought through growth plasticity, low osmotic potential and tissue elasticity, and it may avoid drought through a deep, dense root system, reduction in leaf area by leaf dropping, by generating crystals of calcium oxalate, and through stomatal behaviour. There is disagreement in the literature on the level of drought resistance actually attained by quinoa, and on the phenological phase of its susceptibility. Lund (1992) showed that seed production was reduced with less than 25% of field capacity in the soil, while Vasquez (1993) demonstrated that field capacity had to be decreased to 12.5% before seed yield was affected. Espíndola (1986) demonstrated that water deficiency during inflorescence formation and at flower initiation reduced seed yield by 40% and 65%, respectively. Different investigations show that the phases most drought susceptible with respect to grain production are vegetative, anthesis, and seed set. However, it has also been demonstrated that a certain level of drought in the vegetative phase may have a positive effect on the production of seed. Management practices, such as sowing time, row spacing and plant density, may also influence the water household of the crop. This divergence in results is understandable given the tremendous genetic variability in response to different ecotypes (valley, altiplano, salt desert, subtropics, and humid zones at sea level) reacting differently to a water deficit. This paper presents recent findings on the mechanisms of drought resistance in quinoa, with emphasis on physiological responses such as leaf gas exchange and water relations.
Thesagro:	Cerrado Chenopodium Quinoa Resistência a Seca
Type of Material:	Artigo em anais e proceedings
Access:	openAccess
Appears in Collections:	Artigo em anais de congresso (CPAC)