SEEDS WEEDS. K>7 



attention being paid to the effect of climate, moisture, and temperature on vitality. 

 A discussion is given of the respiratory activities of seeds and the part played by 

 enzyme. 



In the investigations the author employed sweet corn, onion, cabbage, radish, 

 carrot, pea, bean, pansy, phlox, tomato, watermelon, and lettuce seed. These were 

 given a preliminary test, after which the effect of climatic conditions and of moisture 

 and temperature were investigated. Samples of seed from the same lots were dis- 

 tributed to be tested under what are known as trade conditions, dry-room, and 

 basement conditions in Porto Rico, Florida, 2 stations in Alabama, Louisiana, Indian 

 Territory, New Hampshire, and Ann Arbor, Mich. After intervals of 128 and 251 

 days lots of the seed were returned for testing. They were germinated as speedily 

 as possible and the results are given in tabular form. 



Marked differences were shown in the depreciation of the vitality in the different 

 lots as reported. It was observed that there was a close relationship between the 

 precipitation and the loss in vitality, the deterioration in vitality being directly pro- 

 portional to the total annual rainfall. The effect of moisture and temperature was 

 studied, and it was found that most seeds if kept dry were not injured by prolonged 

 exposures to temperatures below 37° C, it being immaterial whether the seeds were 

 in open or in sealed bottles. If the temperature was increased beyond 37° C. the 

 vitality was seriously affected. Seeds kept in a moist atmosphere at temperatures as 

 high as 30° C. were considerably injured within a short period of time, and the 

 degree of injury rises rapidly with the increase in temperature. With the same 

 degree of saturation, the deleterious effect of moisture was as great with samples 

 kept in open as in closed bottles. 



The effect of definite quantities of moisture on the vitality of seeds when kept 

 within certain known limits of temperature was studied, and a marked decrease in 

 the number of germinable seeds was observed with an increase in the moisture and 

 temperature. 



A comparison was made of the methods of storing and shipping seeds in order to 

 pr< itect them from moisture and consequently to secure a better i "reservation of vitality. 

 An attempt was made to ascertain how small quantities of seed should be packed to 

 retain a maximum germinative energy for the longest time, what immediate external 

 conditions are best suited to the longevity of seeds, and the effect of climatic con- 

 ditions on the life of the seeds. In the first experiment duplicate samples of various 

 kinds of seed were put up in double manila coin envelopes and in small bottles, some 

 of the bottles being filled, others only partly full. In order to determine the imme- 

 diate effect of external conditions different lots of seed were subjected to trade con- 

 ditions, dry rooms, and basements, these conditions representing the usual methods 

 of seed storage. 



Samples were distributed as mentioned before and it was found that different 

 seeds behaved very differently under identical conditions. The relative value of 

 different methods of storing seeds in paper packets is shown by the average losses 

 of vitality, as reported from the 8 different stations. The depreciation for trade con- 

 ditions was 36.63 per cent, for dry rooms 21.19 per cent, and for basements 42.28 per 

 cent. Comparing these general averages with the averages given from the bottle 

 samples, it is seen that the loss for those kept in bottles was for trade conditions 3.93 

 per cent, dry rooms 8.08 per cent, and basements 4.51 per cent. Experiments are 

 reported on keeping and shipping seeds in special packages in which the envelopes 

 and bottles mentioned above were sealed with paraffin, etc. The result obtained 

 showed decidedly in favor of protecting seeds in moist climates from the action of 

 the atmosphere. 



The author gives a discussion of the respiration of seeds and the action of enzyms 

 in the preservation of vitality, after which he summarizes his investigations, con- 

 cluding that "the life of a seed is undoubtedly dependent on many factors, but the 



