Wisconsin State Cranberry Growers Association / Wisconsin State Cranberry Growers' Association. Thirty-first annual meeting, Grand Rapids, Wisconsin, January 8, 1918. Thirtieth summer meeting, pavilion, Nekoose, Wis., August 14, 1917
Shear, C. L.
Spoilage of cranberries after picking, pp. 27-30 PDF (910.5 KB)
FulCNGous ROrs According to our investigations, extending over a period of fifteen years about one-half of the loss of berries after picking is due to fungi which develop in the fruit and cause a softening or rot. There are several destructive storage rots. The most frequent and important during the past few seasons have been early rot. formerly called scald, bitter rot or Anthracnose and end rot. The organisms producing these rots are parasitic plants, consisting of very small threadlike flla- ments, which reproduce by means of minute bodies called spores. These are invisible to the naked eye and may be distributed by wind, or water or animal agencies, as insects and birds, and under favorable conditions germinate and grow inside the berries, causing them to be i come soft and worthless. In most cases where these fungous rots de- velop, the fruit apparently becomes infected before picking, and the fungus develops later when the condition of the fruit Is more favor- able for its growth. The surest way of preventing fungous rots is by preventing the infection of the fruit during its growth. This can be most satisfactorily done by spraying with Bordeaux mixture. It has been demonstrated many times in our experiments and also in the experience of growers that sprayed fruit shows much less loss from rot in storage and distribution than unsprayed fruit. Whether sprayed or unsprayed, however, there is always some development of rot after picking, as infection cannot entirely be prevented. We have found by studying the growth and behavior of these rots fungi under carefully controlled conditions of temperature that most of them make but little growth at a temperature of 55 degrees or less, but develop much more rapidly at higher temperatures. This indi- cates the great importance of cooling the fruit as quickly as possible after picking and keeping it cool. Next to high temperature, bruising is probably the most important factor in favoring the development of rot. RAPID RIPENING AND DEATH PROCESiES Besides the fungous rots, we have found in the last few seasons especially, that there is a considerable amount of loss in stored fruit which is not due to fungi but to premature death of the fruit and the physical and chemical changes which follow, causing it to become soft, discolored, and practically worthless. In many cases, especially late in the season, and during the winter from 25 to 75 per cent of spoiled fruit is due to this cause. The cranberry when picked is a living thing, carrying on active life processes and these are continued under ordinary conditions for a considerable period after the fruit £ has been picked. In order to keep fruit fn the best condition after picking, it is necessary to prolong, as much as possible, these ripening or life processes of the fruit and so prevent its death and the destructive changes which naturally follow. The principal vital process which takes place in the fruit after it is picked, as well as before, Is what is known as respiration. This con- sists of the taking in of oxygen from the surrounding air and the giving 28
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