Interaction of arbuscular mycorrhizal inoculants and chicken manure in avocado rootstock production

Abstract

The nursery stage of avocado plant production provides the best opportunity for introducing mycorrhizal inoculants. Three single-species inocula (Acaulospora laevis, Cetraspora pellucida and Pacispora scintillans), an inoculum using a consortium of these three species, an inoculum from a native orchard mycorrhizal community and an uninoculated field soil control were compared experimentally using a factorial experimental design in combination with 8, 17, or 25 g of chicken manure per kg soil. The height, stem diameter, number of leaves, pathogen damage level, and herbivory in “criollo” avocado rootstocks were recorded every two weeks. The leaf area, biomass and mycorrhizal colonization of the roots were measured 7 months after sowing. Overall, responses to mycorrhizal inoculation were minor and increasing fertilization negatively affected most variables. The best inocula were the Cetraspora pellucida and native orchard mycorrhizal community inocula. The negative effects of high chicken manure fertilization on plant growth and health have important implications for nursery management because chicken manure is a preferred fertilizer.