July IS, 1920 



Presoak Method of Seed Treatment 



377 



The results obtained in the field fully corroborate the greenhouse 

 experiments as to the beneficial effect of the presoak method and show 

 that in actual field practice wheat seed injury caused by the formalin 

 treatment recommended for covered smut can be practically eliminated by 

 allowing the seeds to absorb water in the manner prescribed for six hours 



PERCENTAGE OF GERMINATION 



10 20 30 40 50 60 70 



Fig. s- — Graph showing effect of formalin i to 320, with and without presoaking, on wheat seed germination 

 under field conditions: A, control, untreated; B, seeds soaked in formalin i to 32ofor lominutes, drained, 

 kept moist (covered) 6 hours, dried overnight , and planted; C, seeds soaked in water 10 minutes, drained, 

 kept moist (covered) 6 hours, soaked in fonnalin i to 320 for 10 minutes, drained, kept moist (covered) 

 6 hours, dried overnight, and planted. 



before receiving this treatment. The effect of tne presoak method of 

 treatment in also eliminating retardation of germination is an important 

 factor in preventing the attack of soil fungi on seeds or very young seed- 

 lings unduly delayed in germination. Plate 78 shows the appearance of 

 the field plots on the sixteenth day after planting. 



