SEED TESTING 



crop, perhaps even for several 

 years, due to the introduction 

 of weeds. E. Damage caused 

 by introduction of new weeds, 

 which may spread over the 

 farm or the district. F. Loss 

 due to insect and fungous pests 

 introduced with the seed. 



A. Direct loss following the pur- 

 chase of low-grade seeds may be 

 due to one or both of two factors : 

 (1) reduced quantity of seed true 

 to name, and (2) poor germinating 

 capacity of the seeds. Usually low 

 quality seeds are poor in both ways. 



B. When truly high-class samples 

 of seed are bought, less seed is need- 

 ed for a given area than when low- 

 grade samples are used. When a 

 low-grade sample is sown unwitting- 

 ly, the result may be a poor stand, 

 which may be overcome by strong 

 growing weeds, many of which may 

 have been introduced with the seed. 

 Sometimes the whole field may have 

 to be plowed and re-sown, thus 

 causing loss of cultivation, one lot 

 of seed and much time, the last, per- 

 haps, most serious, except the equiv- 

 alent loss of money. 



C. The loss due to parasites may 

 be calculated from the statement by 

 M. Marre that a single dodder stem 

 may spread so rapidly in three 

 months as to kill clover or alfalfa 

 on an area of about 30 square yards ! 

 By experiment, dodder seed has 

 been found to germinate when only 

 half ripe ! The seeds of the dodder 

 and broom rape may lie dormant in 

 the soil for several years. 



D. Introduced weeds may make 

 necessary extra cultivation as well 

 as extra cleaning of the seed crop. 



E. See comment above (F). 



grade 



are undesirable at any soil. 3. Firming in pot 



