The development competition and productivity of linseed and pea-cultivars grown in a pure sowing or in a mixture

Abstract

A field experiment was undertaken to study the growth and productivity of linseed and pea cultivars grown in either a pure sowing or mixture in the vegetative seasons, 2004–2006. Two different mixtures were studied: oil-linseed cv. ‘Flanders’ with grain–peas cv. ‘Ramrod’ (mixture I) or oil-linseed cv. ‘Barbara’ with fodder–peas cv. ‘Phönix’ (mixture II). The cultivars chosen for both mixtures were characterized by similar height. In the mixed sowings, a substitutive model was used, with 50% share of each of the components. Growth and productivity of both species and cultivars grown in a pure sowing or mixture depended on the weather conditions during vegetation. Non-typical weather conditions in the vegetative seasons 2005 (wet) and 2006 (dry) resulted in a decreased 1000 seed mass (MTS) of linseed cv. ‘Barbara’ grown in the mixture, by about 19% and 25%, respectively. Moreover, in 2005 a decreased share of seeds of cv. ‘Barbara’ in mixture I was stated, as compared with the seed share of cv. ‘Flanders’ in the mixture II. Edible peas cv. ‘Ramrod’ grown in the mixture I had reduced the fruiting part of the shoot by about 37%, the lowered number of pods by about 33% and the MTS by about 6%, as compared to its pure sowing. Mutual aggression between the linseed and peas in the mixtures was higher during the seasons of less favorable weather conditions. The significantly higher aggression towards the companion plant in the mixture showed peas cv. ‘Ramrod’ sown in the mixture I. At the same time, the harvest index value of ‘Ramrod’ grown in the mixture I was higher by about 15%, as compared to its pure sowing, which was due to using linseed as supporting plants. The mixture II of fodder peas cv. ‘Phönix’ with linseed cv. ‘Barbara’, proved to be significantly more reliable, as evidenced by the value of the land equivalent ratio (LER=1.20).