Greater emergence force and hypocotyl cross sectional area may improve wheat seedling emergence in sodic conditions

Abstract

Surface crusting of sodic soils is a major problem in the semi-arid tropics when rapid drying after sowing follows light showers, leading to reduced seedling emergence and grain yield. The magnitude of the force exerted by germinating seeds affects the ability of the seedlings to rupture the crust and emerge. This study aimed to determine whether the seed germination and seedling emergence force of wheat (Triticum aestivum L.) seedlings vary among different genotypes at different sodicity levels. Germination and emergence force of seedlings of four wheat genotypes was determined in assays using four solutions with sodium adsorption ratio (SAR) values ranging from 0 to 60. Seed germination and seedling emergence force varied between genotypes at different sodicity levels, with the emergence force of the coleoptile correlated to the cross sectional area of the hypocotyl. The results suggest that the selection of wheat genotypes with rapid germination, higher seedling emergence force and larger hypocotyl cross sectional area, offers a strategy to improve seedling emergence in crusted sodic soils. © 2018 Elsevier B.V.