Optimal Plant Type of Pea for Mixed Cropping with Cereals

Abstract

Pea (Pisum sativum L.) in mixed stand (MS) with one small-grain cereal or in pure stand (PS) is gaining interest for silage production. Breeding programmes, however, target essentially the grain crop, selecting semi-dwarf germplasm. The aim of this study was to assess the impact of pea plant stature on biomass production and competitive ability against cereals. Three semi-leafless pea genotypes with a comparable phenology but contrasting plant stature, i.e. (i) one breeding line (‘1/15b’) lacking dwarfing genes, (ii) one semi-dwarf line with moderate stature (cv. ‘Attika’) and (iii) one semi-dwarf line with short stature (cv. ‘Spirale’), were grown in PS and in binary mixtures with barley (cv. ‘Cometa’) or triticale (cv. ‘Amarillo’) in a Mediterranean environment. Harvest and dry matter yield assessment occurred at waxy stage of the pea grain. Seed densities for pure stands (100 seeds/m2 for pea; 320 seeds/m2 for cereals) were halved for mixtures. The pea genotypes ‘1/15b’, ‘Attika’ and ‘Spirale’ ranked in this order for plant height and pea yield in PS or MS, total (pea + cereal) yield in MS, and pea proportion in MS, indicating the strict association of pea stature with biomass yield and competitive ability. Pea yield and proportion were lower and with smaller genotypic differences in MS with triticale than in MS with barley. The only drawback of the pea ‘1/15b’ was its greater susceptibility to lodging, which emerged as a problem only in PS.