Seedling Emergence of Bambara Groundnut (Vigna subterranea (L.) Verdc.) Landraces at Various Temperature Conditions

Abstract

Bambara groundnut (Vigna subterranea (L.) Verdc.) could be a potential crop of the future well adapted to various agro-ecological conditions and climate change in particular. Growth chamber experiment was therefore conducted to study the performance of Bambara groundnut landraces at various temperature conditions. Four landraces of Bambara groundnut [Ex-Sokoto (cream testa with prominent black spot), Kangiwa-brown (Brown testa), Kangiwa-black (Black testa) and Kaaro (bright cream testa) were imposed to four sets of temperature (20/15̊C day/night, 30/25̊C day/night, 35/30̊C day/night and 40/35̊C day/ night) during its early growth. In the growth chamber, humidity level was maintained at 70%, light at level 2 and photoperiod was set at 12h d-1. Data was collected on daily emergence and then total emergence on day 9th. Design used was split plot with temperature as whole or main-plot and landraces as subplot. Block was treated as random factor. Data on emergence was subjected to GLMM (generalized liner mixed model) procedure in Genstat. Results showed significant (P<0.05) effect of temperature, landraces and their interaction on the total emergence of the seedling at 9 days after sowing. Kangiwa-black and brown showed significantly (P<0.05) higher seed germination than Ex-Sokoto and Kaaro at all temperatures. Highest emergence was recorded at 30̊C in all the landraces (26-96%). Increase in temperature from 30 to 35̊C resulted in reduction in seed emergence but Kangiwa black (93%) and brown (70%) recording higher emergence than Kaaro and Ex-Sokoto landraces (23-50%). Further increase in temperature to 40̊C resulted in reduction in emergence in all the landraces with Kangiwa-black and brown recording 63% emergence while ex-Sokoto and Kaaro recorded no emergence. Results revealed the potential of Kangiwa-black and brown to grow under temperate conditions (20̊C). Ex-Sokoto and Kaaro recorded no emergence at 20̊C. Thus, with increase in temperature from Tropics to semi-Arid and arid tropics as a result of climate change, Kangiwa-black and brown landraces may be better adapted and could be included in breeding programme targeting at survival at temperature stress conditions.