Direct Seeding of Trees 



143 



again broadcasting would waste seed. 

 Seeding from the air involves the 

 same basic procedures as spreading in- 

 secticides and fungicides, except that 

 flight strips must be narrower because 

 seeds fall more sharply than mists or 

 dusts. On the experiment in Maine, 

 flight strips were 50 feet wide, with the 

 plane flying 50 to 75 feet above the 

 treetops. Ground crews must precede 

 the plane to erect flags and wind-socks 

 at corners and along boundaries as 

 guides for the pilot. Distributing de- 

 vices are whatever an ingenious me- 

 chanic can devise to fit the plane and 

 the job. On the Maine job the plane 

 used was a converted N3N Navy train- 

 ing biplane with equipment originally 

 designed for spreading poisoned bran 

 grasshopper bait. The hopper held 

 about 1 7 bushels. Material flowed from 

 the bottom of the hopper through a 

 slot into a pan under the fuselage from 

 which it was blown out by the slip 

 stream through four fanwise diverging 

 channels. Agitators in the hopper were 

 operated by a small gear box and shaft 

 mounted on one wing and driven by 

 wind vanes. With this distributing ap- 

 paratus, the flow of pure pine seed 

 could not be regulated satisfactorily; 

 consequently, the seed was mixed with 

 sawdust. By trial and error, propor- 

 tions of 1 2 of sawdust to 1 of seed and 

 6 of sawdust to 1 of seed, by volume, 



were found to give the 2 desired den- 

 sity rates of approximately 4,000 and 

 8,000 seeds an acre. These rather low 

 rates were necessitated by the limited 

 amount of seed available. Only white 

 pine was sown ; original plans called for 

 red pine also, but seed could not be had. 

 These details on the Maine seeding 

 are cited merely as one example. With 

 other kinds of seed and distributing 

 equipment, the procedures might vary 

 considerably. The Ontario investi- 

 gators, for instance, devised a mecha- 

 nism for distributing undiluted seed 

 through the camera hatch of a Cessna 

 Crane plane. They also have worked 

 with coated or pelleted seed, which 

 increases seed weight by about six 

 times, thus causing the seed to strike 

 the ground with greater force and 

 embed themselves to some degree in 

 the surface soil or litter. The partial 

 embedding, plus the coating of diato- 

 maceous earth and the fly ash, provide 

 more or less coverage for the seed and 

 thereby promote better germination 

 and higher survival. Fungicides, ferti- 

 lizers, and rodent repellents have been 

 incorporated into the seed coatings, 

 but with no significant benefits except 

 possibly from fungicides in reducing 

 losses from damping-off. 



As FOR COSTS : That direct seeding 

 can be done at lower cost than plant- 



