If the storage-room is too dry, the grapes wilt and lose flavor; if, on the other hand, the atmosphere is too damp, the grapes mold. It is essential, therefore, to strike a medium between an atmosphere too dry and one too wet. It is possible that a light fumigation with sulfur or formaldehyde might help to keep down molds in these common storage grape-rooms, but as to the value of fumigation there seems to be no experimental evidence.
Grapes grown on clay lands are said to be firmer and to keep better than those grown on gravel or lighter soils. Some years ago there was an association in Ohio known as The Clay-Growers Association which handled only grapes grown on clay lands. The members of this association believed that their grapes were much more desirable for storage than grapes from regions where the soil was lighter.
Harvesting and Handling Muscadine Grapes
The Muscadine grapes of the South Atlantic and Gulf states are unique in vine and fruit, are used for different purposes and go to different markets from the grapes of the North, so that they may be considered almost a distinct fruit. Not only are cultural requirements peculiar to this fruit, as we have seen, but the methods of harvesting and marketing are quite distinct. These are well set forth by Husmann and Dearing[18] as follows:
"Rotundifolia vines have been almost entirely grown on overhead arbors in the past, the fruit being made into wine, and under such conditions the general practice of jarring the grapes from the vines is perhaps the most practical method of harvesting. If the vines are trained to upright trellises or if the fruit is intended for shipping or table use the grapes should be picked by hand in order to be sound and clean. On account of the presence of leaves, twigs, etc., mixed with the grapes jarred from the vines, wine and grape-juice manufacturers will pay 5 to 15 cents a bushel more for hand-picked grapes. The growers who make a practice of hand picking claim that the work can be done at practically no greater expense than is necessary to shake off and clean a crop, and the increased price obtained for the fruit will more than pay the difference.
"A description of the harvesting of the Rotundifolia grapes by the jarring method will be interesting to those not familiar with it. Poles are attached to sheets of canvas measuring 6 by 12 feet and having leather handles. A man is placed at each end of the sheets and four men with two sheets work together. The wide sides of the two sheets are brought close together under each vine, with the trunk of the vine in the middle. The vines are then jarred, the berries falling into the sheets. Those not caught by the sheets or that have fallen to the ground by the shaking of the trellis when the fruit of the adjoining vines was harvested, etc., and which are usually of the best quality, are picked by hand. The writers are informed that it costs approximately 15 cents a bushel to harvest the fruit on the ground and 12 cents to harvest that which falls on the sheets.
"The fruit is put in boxes or barrels, and if the quantity is not large the leaves, sticks, etc., which become mixed with the fruit are removed by hand. If there is a considerable quantity of fruit some mechanical means, such as ordinary grain fan mills, are used to clean it. After cleaning, the fruit is hauled or shipped to the winery. In wineries with modern equipment there are blowers which thoroughly clean the fruit. These are located near the end of the elevators that carry the fruit to the crusher.
"A common and very objectionable practice followed in harvesting Rotundifolia grapes, especially by the jarring method, is that of gathering the fruit all at once, whereas there should be at least three periods of harvesting. When harvested at one time the best quality of fruit ripens, falls to the ground, and is lost before the harvest is commenced and the last part of the crop is thrashed from the vines in a half-ripe condition along with the ripe fruit. In this manner not only is the first and best fruit entirely lost, but the harvested fruit is inferior in quality, which necessarily results in a poor product from the entire yield."