GREENHOUSE quality control

Procedures in the greenhouse focus on maximizing productivity of cultures (optimal relationship between plant growth, mycorrhiza biomass, and fungal sporulation) and insuring that these cultures remain free of contaminating microbes and pests that might spread particulates from one culture to another or be a detriment to plant health.

Surfaces on three fixed benches are of a heavy aluminum mesh for good drainage and for cleaning. Floors are sealed concrete with a drain under each bench. Benches are disinfected at bi-monthly intervals and floors are washed as needed to remove debris. All watering is performed manually by INVAM personnel to avoid any chance of pot-to-pot contamination and to closely monitor culture development.

High pressure sodium vapor lamps run 14 hours each day to insure a minimum light intensity of 300 µE m^-2 s^-1.

A large stainless steel double sink is used to wash pots just after cultures are harvested (so any particulates on pot surfaces don't dry out and create dust). No raw soils are processed in this room!

A large rectangular stainless steel soil trap is inset in the concrete floor below the sink. The cover is easily removed and the tank is emptied as needed.

Pots and deepots are overseeded for several important reasons: (i) to minimize any bare surfaces where may be passively deposited, (ii) to minimize splashing and movement of surface particulates, and (iii) force plants to grow more slowly and to a similar height (to control lighting, detect any plant health problems, and make it easier to water or apply sprays).

Most cultures, regardless of pot size in which they are maintained, are grown for 4-5 months to minimize buildup of saprophytes in the growth medium and excessive senescence of roots. If grown for > 5 months, watering is carefully regulated and plant health monitored daily.