ARTIFICIAL DISPERSAL OF FOREIGN POLLEN INTO A SCOTS PINE SEED ORCHARD

Dyed pine pollen was released a total of 24 times from two directions outside a Scots pine seed orchard (distance between rows 7 m, that wit hin rows between grafts 3.5 m). The distribution of pollen within the orchard was measured using 49 samplers of the rotorod type. Meteorolog ical measurements were carried out during the experiments. The amount of pollen released was approximately 1.210(10) grains; the total caug ht was 39300 grains. When the releases took place perpendicular to the rows, the pollen plume was wider and shorter than when the release wa s from a direction parallel with the rows. The airborne pollen concent ration decreased inside the orchard at a significantly higher rate whe n released from a point perpendicular to the grafts than with parallel release. Almost all the pollen was caught within 30 minutes of releas e. The pollen was resuspended in the air in only small quantities. The re are some possibilities of reducing the amount of foreign pollen fro m at least short distances by modifying the raw structure within orcha rds.