MR. SHERMAN: What is the best method of treating the chestnut seeds in the fall to prevent the development of weevils?
DR. McKAY: Of course, there are several ways of treating the nuts for weevils. One is the old hot water method. All of us can heat water. We have to heat it to about 120 degrees. So hot, you can't hold your hand in it. Immerse thirty minutes for an average size nut. Now in connection with the spoilage and rotting that is another matter. We believe in harvesting chestnuts promptly, storing them before they dry out. We of course store our chestnuts in cans. Cans with lids and holes punched at either end.
MR. O'ROURKE: Are there any other questions pertaining to seeds?
MEMBER: I would like to caution persons outside the weevil belt about being very careful if you get nuts that may be infested. Leave your nuts in a small jar and you have the advantage of watching the weevils actually emerging. You can pick the nuts out about February, and you can select all the nuts that are sound. Once in awhile a weevil will live through the winter. One thing we should all be thinking about is that the nurseryman has to produce grafted trees in order to fill a demand, and those nut trees must be produced cheaply and he must use methods which are highly efficient.
MEMBER: Has anyone tried to deep freeze?
DR. CRANE: We tried that just this past winter. For a couple of years back one individual had asked us why we didn't freeze them. Last winter we did. We stored three gallon buckets at two temperatures. One at zero and the other at ten degrees below—hard freezing temperatures. Those nuts stayed frozen from early October until the next April. We brought them out and examined them one morning. The first thing we did was taste them. Those nuts we ate when first opened and you could tell them from no other chestnuts. They were nice eating, sweet. We let those chestnuts thaw evenly at room temperature. That evening we examined them and it's hard to describe what the transformation was in those nuts. In the first place was the deterioration that had gone on as soon as the tissue thawed ... They were dripping water. The tissue had burst and the water just flowed. On the other hand, about an hour after they thawed out, when we first examined them just as they thawed out, you would be amazed at how tender they were. They would melt in your mouth. Freezing apparently breaks down the tissue. The tissue is as soft as it can be. Apparently this freezing transformed some of the starch to sugar. The rub is that it won't keep for even two or three hours.
MEMBER: They might keep if you put them in the soil first.
DR. CRANE: The tissue is ruined.
MR. O'ROURKE: We have now decided certain things pertaining to seed germination. Then we are confronted with the problems of seedling versus clonal rootstocks. I do not know whether or not there have been clonal rootstocks selected for Chinese chestnut. I am sorry to have to ask Dr McKay to talk again but he knows more about it.
DR. McKAY: I can only tell you about the experiment we started this spring on clonal stocks of chestnuts. We have just this year's results. Unfortunately we didn't get good results. We took ten seedling trees. We used nursery trees, large five-year old trees, with vigorous root system, ten seedlings, and got from them 20 roots. We took roots the size of your finger with a lot of feeding roots, and we grafted onto those five times four. We took four per variety. We used five varieties of chestnuts, and all five of those each had four pieces and we had ten of those seedlings. We wanted to find out whether any of those ten seedlings would give us a better set of these five varieties than any other trees. In other words, we are trying to get a start on a clonal rootstock. We used a splice graft. We simply took a piece of scion and spliced it right on the end of the root. We had four of those in the bundle, and we had five per seedling and we had ten of them. That made 20 in all. We planted in a cold frame, with cheesecloth covering to keep the temperature from getting too high. Eventually, if this thing works, we will establish a clonal line. We planted those ten original trees but you will be surprised. We can go back to the original tree if we succeed with clonal lines, so a chestnut variety we hope will be grafted on a line of stock that came from that one original tree. Bear in mind this is the method and it remains to be seen whether it is going to work for chestnuts.