The relationships between relative water content, chlorophyll synthesis and yield performance of yam (Dioscorea rotundata) as affected by soil amendments and mycorrhizal inoculation

Abstract

The response of yam to inoculation with two species of vesicular-arbuscular mycorrhizal (VAM), Glomus mosseae and Glomus etunicatum and applications of fertilizer, and manure was investigated. Field experiment was conducted at the research farm of Botany and Microbiology Department, University of Ibadan, Nigeria. The treatments were arranged in a factorial randomized complete block design. There were four levels of VAM inoculation. The yam plants were either inoculated with a VAM fungus or not. Manure and NPK fertilizer were also applied as treatments. Each of the VAM was either combined with manure or NPK fertilizer. Chlorophyll synthesis, relative water content (RWC) and dry matter accumulation were investigated. The results showed that there was enhanced chlorophyll content in yam inoculated with the VAM with G. mosseae being more effective when combined with manure. RWC and yield of yam were also significantly influenced by the treatments. RWC was found to affect the chlorophyll production when water became limited. Chlorophyll content was also found to have effect on yam productivity. Combinations of mycorrhizae with the soil amendments are highly promising for sustainable yam production in degraded soils.