+Harvesting and Nut Storage+
Harvesting of Chinese chestnuts has proved to have definite requirements if the nuts are to be obtained in the best possible condition. The nuts are quite susceptible to rots of several kinds and must be properly handled to keep losses at a minimum. They are also very easily and quickly injured by exposure to the sun, with the consequent, high temperatures and drying. If the nuts are to be stored for any length of time, as is necessary when they are to be used for seed purposes and as will be necessary when they are to be marketed for eating purposes during the Thanksgiving and Christmas holiday seasons, it is paramount that they be picked up from the orchard at not more than two-day intervals. Cleaning up all dropped nuts at daily intervals is most desirable.
At the end of each day the harvested nuts must be placed in cold storage at temperatures between 32°F. and 45°F. It has been found that a nearly air-tight container is required in order to maintain a relative humidity of 100% and prevent too much drying of the nuts. A 50-pound tin lard can with one 20d nail hole in the side near the lid has proven to be a good container for large quantities and these same cans also make good shipping containers merely by wiring on the lids. One-gallon friction top syrup cans with a single nail hole in the side make a good container for smaller quantities. In air-tight containers the nuts do not decay but germination capacity is quickly destroyed and bitter flavors develop quite rapidly. Nuts to be used for eating purposes shortly after harvest may be stored at lower relative humidities but should be placed in cold storage. A loss of about 15% in weight from the fresh weight of nuts is necessary to reach proper eating quality. Nuts dried to this extent are sweet and palatable but cannot be stored for any length of time and fail to germinate well when planted.
The experimental study of chestnut storage problems is being continued with the hope of working out still better methods. The manner of marketing chestnuts so that they will reach the consumer in a desirable condition also is still to be worked out, but it appears possible that retail cold storage and packaging in moisture-proof bags which are pervious to CO_{2} and O_{2} give promise at present. Probably the most promising aid to an increased storage life of chestnuts will come through the selection of trees for propagation and planting that produce nuts of superior resistance to storage rots. There is rather great variation among seedlings in this respect, some being-quite superior, although no completely resistant seedlings have yet been found.
+Discussion and Conclusions+
The perishable nature of the nuts of the Chinese chestnut has probably been the greatest drawback to an earlier acceptance of this crop as an adjunct to the horticulture of the Southeast. It has been only in the past few years that enough has been learned about the harvesting and storage requirements to permit the storing of these chestnuts so that they can be marketed in an orderly manner either for eating or for seed purposes. Storage losses through periods up to six months have been held to less than 10% for a mixture of nuts from all the trees at Philema. Storage tests of nuts from individual trees have shown a range in keeping quality from no loss after six months' storage to nearly 100% loss. By culling out the trees producing nuts with a high rate of spoilage under the best storage conditions it should be possible to reduce storage losses to a minimum. Every grower of seedling trees should follow this same process of culling out or topworking trees producing nuts of poor keeping quality if the industry is to grow and prosper, since otherwise the offering of spoiled nuts for sale to the consumer will soon destroy the demand for the nuts.
There is no question but that the Chinese chestnut tree is very well adapted to the Southeast. It has proven to be healthy, vigorous, and productive. Yield records at Philema show actual yields of more than 1,000 pounds per acre and potential average annual yields of 1,500 or more pounds per acre are not out of reason. In 1947, in the Brown tract at Philema, if all the trees that bore nuts had been collected into a solid block the yield per acre would have been nearly 2,500 pounds. Crowding of the trees in the Brown tract is becoming serious at 11 years of age with a 25 x 25 foot spacing. Alternate-year bearing is becoming apparent and the stand of trees must be thinned immediately. Because of such potential yields and because rather extended storage of nuts of varied keeping quality is now economically possible the future of the chestnut industry in the Southeast is very promising.
The selection and propagation of selected seedlings is desirable as a means of advancing the industry at a more rapid rate. The propagation of selected seedlings offers a problem because of lack of compatibility between some stocks and scions. Since the chestnut is almost completely cross-pollinated it may be necessary to develop special plantings of two or three selections as a source of seed nuts for the production of stocks. Such plantings might possibly produce seedlings of quite uniform and desirable characteristics, but this prospect, is not very promising. Certainly, the evidence points to the conclusion that scion selections must be worked on stocks of the same strains if incompatibility is to be held at a minimum.
There is a further problem in the propagation of varieties on seedling rootstocks in the nursery. Only one propagator appears to be having much success in this art but others must learn it. Topworking of older trees by the inlay bark graft is generally successful and older seedling orchards can be worked over to improved selections without difficulty so long as the stocks are of compatible strains. Time will be required to work out the details of the solution for this problem but they will be worked out.
In the selection of improved seedlings for propagation the strictest attention should be paid to the important characteristics of tree vigor, precocity, productiveness, nut size, attractiveness, and keeping and eating quality, and type of bur opening. These characteristics have been previously discussed but it is well to emphasise their importance. The tree that comes into bearing at an early age seems likely to be more productive in later years. The nuts should be no smaller than 45 nuts to the pound and be attractive to the eye of the buyer. Most individuals prefer nuts with a bright and shining surface free of fuzz and with a fairly rich mahogany or chocolate color. Keeping quality is, of course, of great importance and should be carefully determined. Eating quality is generally good but distinctly superior selections may be found in the future. For the most part eating quality is dependent on the proper curing of the nuts. The type of bur opening is more important than usually considered, as it materially affects the satisfactory harvesting of the nuts. From the commercial standpoint it appears that the most desirable bur should drop from the tree with the nuts still in it but be well split so that the nuts can be readily removed. Such a bur type prevents exposure of the enclosed nuts to the hot sun while on the tree and reduces injurious drying to a minimum yet permits rapid gathering of the nuts in the burs for later mechanical separation. Nuts that drop free from the burs are more subject to injury by drying and require more hand work in gathering. Burs that do not split readily would be more difficult to separate mechanically; and mechanical aids will be necessary for the economical daily gathering of the nuts in commercial orchards.