CHAPTER VIII 



FOREST TREE SEED AND SEED COLLECTING (Continued) 

 1. SEED PRODUCTION 



FEW people are sufficiently familiar with forest tree seed and 

 with methods of collecting and handling it to be safely trusted 

 to collect the fruit and extract the seed. For this reason it is 

 preferable to purchase it from a trained collector or dealer when 

 but a small quantity of seed is desired. The aim of the collector 

 should be to secure seed of high quality at the least cost per 

 pound. Usually a full seed crop and high quality go together, 

 also the cost of collecting rapidly decreases with the fullness of 

 the crop. 



Years when the seed of a given species is produced in abundance 

 are known as seed years for that species. Intervening years are 

 known as off years. During off years the seed is not only in small 

 quantity but that which is produced is more keenly sought after 

 by birds and rodents because of the limited supply. Insect damage 

 is also likely to be greater. For these and other reasons the small 

 crop in off years is usually of low quality. 



The seed year of a given species usually means an abundant 

 ' crop throughout most of its range. It may, however, be entirely 

 lacking in restricted regions. On the other hand, during an off 

 year limited portions of the range may experience a fair, or even 

 a full, crop. We have little knowledge of the causes of seed years 

 and off years, and although this is a matter of fundamental im- 

 portance in silvicultural operations we cannot foretell with any 

 degree of accuracy when seed years will occur. 



There is a voluminous European literature on the various 

 problems of seed production, notably the writings of Lauprecht, 

 Schwappach, Wimmenauer, and more recently those of Soboled 

 and other Russian foresters. As pointed out in a recent review 

 of the subject by Zon and Tillotson, 1 the results of the earliest in- 



1 Zon, R. and Tillotson, C5. R.: Seed production and how to study it. 

 (Proc. Soc. Am. For., vol. VI, pp. 133-152. 1911.) 



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