Volume 39, 124-128

Tropical Grasslands (2005) Volume 39, 124–128

Research note: Effect of different seed treatment options on dormancy breaking, germination and emergence of Ziziphus mucronata (buffalo thorn) seed

ABUBEKER HASSEN¹, N.F.G. RETHMAN¹ AND W.A. VAN NIEKERK²

¹Department of Plant Production and Soil Science, and
²Department of Animal and Wildlife Science, University of Pretoria, Pretoria, Republic of South Africa

Abstract

The suitability of different pre-planting seed treatment options to break hard seed dormancy and enhance germination and/or emergence of Z. mucronata seeds was compared in 2 separate experiments. In the first experiment, the effects of scarification, immersion in boiling water for 1 or 5 minutes and treatment with concentrated sulphuric acid (94%) for periods of 10, 20, 30 or 45 minutes were evaluated in a petri dish experiment. In the second experiment, Ziziphus fruits were either soaked or un-soaked in water, prior to seed removal, and the seeds were treated with sandpaper, sulphuric acid or boiling water. Seedling emergence was measured in seedling trays in a glasshouse. Two acid concentrations (36 N and 94%) and 2 durations of immersion (10 and 20 minutes) were evaluated. In the first experiment, scarifying with sandpaper or treatment with concentrated sulphuric acid (94%) significantly (P < 0.05) reduced the level of hard seed. However, treatment with sulphuric acid for a minimum of 20 minutes also increased (P < 0.05) the amount of dead seed. In the second experiment, scarification with sandpaper or treatment with sulphuric acid (94%) for 10 or 20 minutes was most effective in breaking seed dormancy. Treatment with boiling water was ineffective in breaking dormancy in both experiments.