Improving seedling production for Vitex doniana

Abstract

Uniform germination is one of the important agronomic requirements for successful domestication of wildharvested economic plants. In this study we investigated the effects of storage and hydration-dehydration regimes on Vitex doniana seed viability, germination speed and seedling growth and vigour. These effects were tested in a factorial combination of four storage durations (0, 2, 4 and 8 months) and five hydration-dehydration regimes including the control, alternating one hour soaking in tap water with eight hours sun-drying for 3, 7, 14 and 21 days. After two months storage at room temperature, germination percentage was not significantly different from initial germination; seed viability and germination decreased with storage beyond two months. For the first time, germination in V. doniana reached 83%, for seeds stored for two months and then submitted to 21 days of hydration-dehydration cycles. Two months storage combined with hydration-dehydration regimes for 14 or 21 days improved germination speed and seedling growth and vigour. We recommend that fresh seeds be stored for a maximum of two months and stratified by consecutive hydration-dehydration cycles for 14 or 21 days to obtain a homogenous seedling cohort. These results represent an important step towards domesticating V. doniana in West Africa.