MR. O'ROURKE: The suggestion of soaking them in water a few days is well taken, because a great many have recommended it. Most folks recommend changing the water daily. By changing the water you replace the oxygen which would be in the water, and you also eliminate any toxic substances which may have leached out of the shells during the preceding 24 hours.
DR. MCKAY: I'd like to mention the reason for raising this question. Dr. Crane has the idea that there is no definite rest period in the pecan nut; if they are soaked in water they will sprout at any time.
I decided I would test that hypothesis, so I stratified one group of nuts of about four pounds. Another lot of four pounds I kept in the laboratory dry all winter long. Then I planted the two lots of nuts this spring together, side by side, in the cold frame. Today there is not a single seedling growing out of the dry lot, and there is a perfect stand in the group that was stratified.
To me that means that there is a definite rest period in the pecan seed.
I don't see how you can get away from it.
MR. O'ROURKE: I am going to stick my neck out a little bit. I have absolutely no basis to make this statement, but it does give us something to think about. That is the greater the distance towards the north that certain species of plants may have migrated or disseminated, the greater the rest period requirement. That is a protective device for a species to persist in northern climates, because if it were not for this rest period, those seed would germinate in the fall of the year, and the young seedlings would be frozen out immediately. But by having the rest period requirement over winter, the seedlings do not germinate until the following spring, and the plant can persist. I am speaking now in general of northern plants. I am wondering if the pecan species in itself may not be variable in that the southern pecan does not need a rest period, and the northern pecan is beginning to develop the rest period requirement.
MR. HARDY: Mr. Chairman, I am inclined to think there may be some other factor entering into the picture there. A pecan carried through winter in a dry condition at normal room temperatures would be liable to develop quite a bit of rancidity by spring. Furthermore, nuts that have been held over so long in a dry condition may still be good and may germinate the second year. I'd hesitate to destroy that planting until next spring, and to my notion that does not indicate dormancy so much as it would possibly indicate the inhibition of growth by some other products developed during that storage period.
MR. O'ROURKE: You have brought up a very important point and something we should not neglect. It may be that drying to a certain degree will induce dormancy, a grievously overworked word, but you know what I mean. It may take two years for the seed to germinate, as Mr. Hardy has suggested. If you can leave them in that cold frame over this winter, maybe you can tell us next year just what happened.
MR. PATAKY: If we take nature's way, watch a squirrel plant a hickory or black walnut. He will bury it about an inch deep, and it will stay moist all winter long, the same as if it were stratified. But if you take a nut and store in a hot place you are going to slow up or kill that germ.
You can do that very easily in a chestnut. Take a little advice from nature itself in the locality where you are. If you are in the South, that nut can start growing in the fall, and it probably won't hurt it, but if you are in the North, you don't want to start a nut growing in the winter, because it's going to get winter killed.
MR. O'ROURKE: In all probability the amount of oxygen about the germinating seedling might be quite a factor. The shallow planted seed will have more oxygen available than deep planted seed, everything else being equal.