Early growth of field peas under saline and boron toxic soils

Abstract

Boron and salinity are both toxic to plant growth in high concentrations and frequently occur together. Field peas are one of the major break crops in Western Australia yet little is known about their tolerance to the combined influences of salinity and boron. A glasshouse study was conducted to determine the influence of salinity (0 and 6 dS/m) and boron (5 and 20 mg/kg) and the combined effects of both on the early growth of two field pea varieties ‘kaspa’, the predominant variety grown in south-east and Western Australia, and an older variety, ‘parafield’. Levels were chosen as the upper levels for cereal production. Salinity was found to be the main inhibitor to plant growth in both ‘Kaspa’ and ‘Parafield’ reducing plant height, root length and the number of nodes on the main stem. No interaction was observed between the combined effects of salinity and boron toxic soils. ‘Kaspa’ was more tolerant of boron toxic soils than ‘Parafield’ with no significant difference between low and high boron soils. In ‘Parafield’ boron significantly reduced plant growth under low saline conditions. Results suggest that breeding for boron tolerance has had some success, but that there is an urgent need to develop cultivars with greater salinity tolerance and screening of accessions held in genebanks is required to determine if diversity for salinity tolerance exists.