EFFECT OF MYCORRHIZAL INOCULANTS IN THE DEVELOPMENT OF MEXICAN LANDRACE AVOCADO ROOTSTOCKS

Abstract

The aim of this work was to assess the effect of two arbuscular mycorrhizal fungi (AMF) inoculants in the development of avocado rootstocks. Seeds of Mexican landrace avocado (Persea americana Mill. var. drymifolia) were used, with two commercial inoculants: T1 containing Glomus fasciculatum, G. constrictum, G. tortuosum, G. geosporum,and Acaulospora scrobiculata, and T2, containing G. mosseae and G. cubense.  The plants inoculated with AMF showed more rapid growth than the no inoculant control as measured by plant height (50% and 54%), stem diameter (35% and 36%), leaf number (48% and 37%) and length (31% and 40%), and root fresh weight (85% and 59%); however, no significant differences were observed between T1 and T2. The chlorophyll concentration in the leaves from T1 was 16.4% and T2 was 19% higher than the control suggesting a higher photosynthetic capacity in T1 and T2. Finally the shoot/root ratio, as indicator of the potential development of plantations, was 79% and 50% higher in mycorrhizal plants than in the control. In conclusion both T1 and T2 inoculants improved growth rate and vigor of avocado nursery rootstocks producing higher quality plants.