Effects of VA [vesicular arbuscular] mycorrhizal inoculation on 18 selected crops in a phosphorus deficient soil

Six agricultural crops, six fruit trees, and six forest tree species were screened for their response to inoculation with three different VA [vesicular arbuscular] mycorrhizal species and application of complete fertilizer, grown in a grassland soil. The degree of mycorrhizal depending for each plant and presence of host specificity between micro- and macro-symbiont was also evaluated. Growth responses of mycorrhiza inoculated plants fertilized with 60-60-60 kg NPK/ha were always better than the uninoculated-unfertilized control and the fertilizer alone treated plants. The three VA mycorrhizal species namely: Glomus etunicatum, Glomus macrocarpum and Gigaspora margarita were equally effective on improving growth of the plants, although G. margarita inoculated plants almost always gave a higher value in some parameters monitored. The 18 host plants were grouped according to their dependency to mycorrhiza. Plants highly responsive to mycorrhizal inoculation are: mungbean, eggplants, guava, papaya, Acacia mangium, Paraserianthes falcataria, Acacia auriculiformis, Kariskis corn, peanut, soybean, citrus, and raintree. Total biomass increases of these plants were always greater than 40%. The highest biomass increases were at 1,650% and 1,367% over the fertilizer alone treated plants in Kariskis inoculated with Gl. etunicatum and Gl. macrocarpum, respectively. With G. margarita inoculation, a 1,630% increase over the fertilizer alone treated plants was observed in P. falcataria. Guyabano and mahogany were intermediately dependent to mycorrhiza and obtained growth increases of less than 40% increase over the fertilizer alone treated plants. Upland rice, cacao, and langka were not dependent to mycorrhiza. All the host plants formed association with the three VA mycorrhizal species implying that there was no host specificity observed among the mycorrhizal fungi. However, differences in the extent of growth improvement by the mycorrhizal fungi for each plant were due to the presence of host preferences