New Year, New Substrate

Starting in 2015, AMF cultures at CICG will be multiplied in a new substrate consisting of a soil A horizon mixed with quartz sand. The change was due to the low sporulation observed for cultures in the substrate previously used (a mixture of soil: sand: expanded clay, 1:2:2). Difficulties in achieving a standard particle size for the expanded clay and the time invested on washing the river sand contributed also to change the substrate.
The new substrate is a 1: 1 (volume: volume) mixture of a soil collected in a specific area on campus V of FURB mixed with quartz sand, whose particle size is 0.9 mm. The quartz sand is inert, comes from a commercial company and has guaranteed to have the same standard grain size. The substrate pH is 5.2 and it is not limed to raise pH because AMF isolates from Brazilian soils are derived mostly from soils with pH 5.2 or less.
Besides the change of the substrate, the host plant to be used for the multiplication will be Brachiaria brizantha, which is more resistant to attack by pests and grows well in the substrate at pH 5.2. The use of sorghum, as was done so far, was abandoned because it attracts many phytophagous insects that jeopardized the multiplication of cultures, if any chemical control was not done.