Efficiency of the On-Farm Mycorrhizal Inoculant and Phonolite Rock on Growth and Nutrition of Schinus terebinthifolius and Eucalyptus saligna

ABSTRACT: The production of tree seedlings with high survival rate and growth is influenced by the substrate, which may be composed of biological and non-biological materials that help plant growth. The objective of this study was to evaluate the efficiency of a mycorrhizal inoculant on farm and the use of a potassic rock (phonolite) on growth and nutrition of Eucalyptus saligna Sm. and Schinus terebinthifolius Raddi under greenhouse conditions. Both species were assigned to three mycorrhizal treatments [no inoculated control (SP), no inoculation + pulp sludge and carbonized rice husk (LC), and mycorrhizal inoculant (IN)] and four phonolite rock treatments [no phonolite (F0) and addition of phonolite in particle sizes of 0.037 mm (F1), 0.074 mm (F2), and 0.149 mm (F3)]. The IN treatment consisted of inoculum of Claroideoglomus etunicatum (Becker & Gerd.) C. Walker & A. Schussler (isolate MGR288A) and Dentiscutata heterogama (Nicol. & Gerd.) Sieverd. F.A. Souza & Oehl (isolate PNB102A) produced on farm with pulp sludge and carbonized rice husks. After 120 days, plants were evaluated for height, stem diameter, shoot and root dry weight, shoot K and P, and mycorrhizal colonization. Growth parameters were used to calculate the Dickson Quality Index (DQI) for seedlings. Growth parameters of S. terebinthifolius demonstrated synergistic and positive effects when different particle sizes of phonolite and on-farm mycorrhizal inoculum were used together. For E. saligna, phonolite and on-farm mycorrhizal inoculum had little effect on growth parameters, although the mycorrhizal inoculum increased K and P content in the F0 and F2 treatments. The DQI of S. terebinthifolius was higher with IN compared to SP and LC with phonolite, whereas this index was not influenced by most treatment combinations for E. saligna. Overall, the percentage of mycorrhizal root colonization for both species was significantly higher when phonolite was present in the substrate. The interaction of mycorrhizal inoculum produced on farm and phonolite rock has the potential to increase growth and nutrition of S. terebinthifolius and E. saligna.