Figure 1. Maple cuttings in ground bed with constant mist. This photograph 



shows the type of mist produced. 



(D) Plastic Covered Bench in Greenhouse ivith Fan Aeration. This was 

 based on a report by Sweet and Carlson (4) in which they found that 

 apple and cherry cuttings could be rooted in a bed supplied with inter- 

 mittent mist in an air chamber covered with a canopy of plastic sheeting. 

 Through this a stream of air was drawn by an exhaust fan. A bed very 

 similar to this was set up, size 6' x 3', and filled with sawdust. It was 

 supplied with intermittent mist, operated by the drying action of an "arti- 

 ficial leaf" attached to a solenoid valve. 



(E) Greenhouse Bench Aerated from Beloiv. This was a wooden bench, 

 3' X 6', fitted with an air-tight metal bottom. Above this was a one-inch 

 air gap. Above the air gap the medium rested on hardware cloth sup- 

 jjorted by wood slats spaced one inch apart. This permitted air to pass 

 continuously through the sawdust in which the cuttings were inserted. This 

 bed also received interinittent mist. 



(F) Greenhouse Bench ivitli Tii^hl Plastic Cover. Several descriptions of 

 this type of bed have been published in nursery trade journals and else- 

 where. Typical of these is the one described by Coggeshall I f I . Essential- 

 ly, this consists of a propagating bed enclosed above by a moisture-tight 

 covering of plastic sheeting supported usually by wire netting at some 

 distance above the cuttings. Theoretically this is supposed to need little 

 or no additional water, the vapor from the water-soaked medium keeping 



