Can Hydro-Priming Improve Germination Speed, Vigour and Emergence of Maize Landraces under Water Stress?

Abstract

We evaluated whether hydro-priming could improve vigour characteristics and seedling emergence of local maize (Zea mays L.) landraces compared to two commercial hybrids under water stress at the University of KwaZulu-Natal, Pietermaritzburg. Seeds from local landraces were produced and characterized according to kernel colour, white (Land A) and purple (Land B), and compared to two hybrids, SC701 and SR52, which are popular amongst local farmers. Seeds from each variety were soaked in water for 0 hours (unprimed or control), 12 hours and 24 hours, and germinated in a germination chamber at 25 °C for 8 days. Parameters measured included final germination, mean germination time (MGT) and germination velocity index (GVI). Seedling emergence was performed in seedling trays, using pine bark wetted to 25% or 75% of field capacity (FC), for 21 days in a temperature-controlled glasshouse (25 °C day; 15 °C night; 60% RH). Parameters measured included final emergence, mean emergence time (MET), root and shoot lengths, and leaf area. Priming landraces for 12 and 24 hours reduced MGT by 9% and 7%, respectively, compared to 5% in hybrids for both 12 and 24 hours priming. GVI of landraces was improved by 40% following 12 hours of priming. GVI of hybrids was 11% and 7% slower than landraces after priming seeds for 12 and 24 hours, respectively. Priming seeds for 24 hours improved emergence at 25% FC. Priming seeds for 24 hours reduced MET for all varieties. Priming seeds for 12 and 24 hours increased leaf area by 33.8% and 29%, respectively. Hydro-priming seeds for 12 and 24 hours, respectively, improved GVI, reduced MGT and improved emergence and MET of maize landraces under water stress. Performance of hybrid seeds remains superior to that of landraces even after seed treatment to improve germination and vigour. The positive response of landraces to seed treatment, and improved performance under water stress conditions, suggest that there is a need to identify genes for vigour in landrace maize.