Effects of invigoration and spacing on growth and seed production of four bambara groundnut (Vigna subterranea (L) Verdc) Landraces

Low production of bambara groundnut in Indonesia is due to low quality seeds and the use of less optimal cultivation technology. Objective of the research was to obtain information on the effects of invigoration and spacing on the growth and seed production of four of bambara groundnut landraces, namely Sumedang, Sukabumi, Tasikmalaya, and Gresik. Field experiment was conducted from November 2015 to June 2016 at Dramaga, Bogor and seed processing laboratory. The experiment utilized three replicate split plot design. Invigoration was the main plot that comprised of three levels, i.e without treatment, matriconditioning + Rhizobium sp., and hydropriming. Sub plot was the spacing that comprises of three levels, such as 40 x 10cm, 50 x 20cm, and 60 x 25cm. Result showed that invigoration increased the emergence field of four landraces, but did not increase plant height in all landraces. The spacing of 40 x 10cm increased plant height for Landrace Sumedang, Sukabumi and Tasikmalaya. Hydropriming increased the canopy diameter on the Sumedang and Tasikmalaya and the spacing of 60 x 25cm increased the canopy diameter for all landraces. Seeds without and with invigoration at a spacing of 60 x 25cm gave the highest yield of DW pods and DW pods per plot for all landraces. Invigoration with hydropriming at a spacing of 50 x 20cm and 60 x 25cm increased yield for all landraces. Seed germination was not affected by all invigoration and differences in spacing.