Competition and Productivity in Mixture of Oats and Wheat

Abstract

The research assesses the productivity of mixture of oats (Avena sativa) and wheat (Triticum aestivum), and compares two different approaches used in plant competition studies: replacement (substitutive) designs and additive designs. The experiment was carried out on sandy loam soil at the Experimental Station of Agricultural University of Wrocław (Poland). Oats and wheat were grown for grain as sole crops and in 1 : 1 replacement mixtures at three rates of seeding: 150, 300 and 600 viable seeds m )2 . These designs allowed mixtures seeded at a rate of 300 and 600 seeds m )2 to be analysed according to either a replacement or an additive approach. In 1999, pure stand wheat and oats-wheat mixture yielded significantly more grain than oats grown alone but in 2000 there was no difference in yield. Wheat outcompeted oats in mixture but the relative competitive ability of the two species changed little with increasing seeding density. Relative yield total (RYT) for grain was significantly >1.0 (RYT ¼ 1.07) in 1999 for the lowest seeding density, showing partial complementarity in use of limiting resources by the species in mixture. Based on grain yields, the results obtained from substitutive and additive mixtures were similar with respect to the relative yields and relative competitive ability of the two species concerned.

Organic and conventional management of mixtures of wheat and spring cereals

“…The use of small grain mixtures is promising for both conventional and organic growers, albeit for different reasons. Yield advantages of cereal mixtures over sole crops have been reported under both high (Jokinen, 1991;Sobkowicz and Tendziagolska, 2005) and low (Jokinen, 1991) input environments.…”

“…However, this difference in maturation times may increase yield due to staggered timing of resource requirements (i.e. complementarity) (Sobkowicz and Tendziagolska, 2005). Also, early season vigor has a large impact on the competitiveness of each component (Sobkowicz and Tendziagolska, 2005) and whether a mixture maintains its ratio from planting to harvest.…”

“…complementarity) (Sobkowicz and Tendziagolska, 2005). Also, early season vigor has a large impact on the competitiveness of each component (Sobkowicz and Tendziagolska, 2005) and whether a mixture maintains its ratio from planting to harvest. Vigorous allelopathic species may outcompete the other components in the mixture, resulting in almost a monoculture at harvest (Juskiw et al, 2000a).…”

Associação de características de planta em cultivares de aveia com habilidade competitiva

“…A competição entre plantas ocorre quando um (ou mais) dos recursos necessários ao desenvolvimento e crescimento delas se encontra em quantidade limitada para atender às necessidades de todos os indivíduos presentes no meio. Pode ocorrer competição intra e/ou interespecífica -uma podendo ser mais representativa que a outra, dependendo do nicho que cada espécie ocupa no ecossistema que dividem (Passini, 2001;Sobkowicz & Tendziagolska, 2005).…”

Lettuce and marigold intercropping: crops productivity and marigold's flavonoid content

“…Furthermore, intercropping might promote increased biological efficiency of associated crops, and changes in growth cycles and composition of intercropped species (SOBKOWICZ & TENDZIAGOLSKA, 2005;MONTEZANO & PEIL, 2006). However, most studies on intercropping only address horticultural species (CECÍLIO FILHO & MAY, 2002;BEZERRA NETO et al, 2003).…”