July, ipip 



BETTER FRUIT 



Page 5 



due to one of several causes. Bees are 

 essential for pollenizing the blossoms, 

 and if there are none in the vicinity, or 

 if wet, cloudy days during the bloom- 

 ing period prevent their visits from 

 flower to flower, only a poor set of fruit 

 can be expected. 



Still other trees set fruit and carry it 

 until about midsummer, when it falls 

 from the tree. This is quite common 

 where trees are growing in sod or in 

 soil that becomes dry during summer. 

 Cultivating the sod or keeping the dry 

 soil moist during midsummer will usu- 

 ally benefit this condition. 



Many varieties of pears and plums 

 and some varieties of cherries are quite 

 self-sterile. They need other varieties 

 of the same fruit planted nearby, which 

 bloom during the same period and 

 cross-pollenize their blossoms, to pro- 

 duce a good set of fruit. For instance, 

 the Angouleme pear is often planted 

 near the self-sterile Anjou to pollenize 

 it. Where self-sterile trees are of bear- 

 ing age it is better to top-graft branches 

 of some of these trees with pollenizers, 

 as several years may be gained in se- 

 curing blooming wood. 



Photo by California Horticultural Commission. 



Heavy producing apricot tree, illustrating fruiting wood low down in the branches. 



Efficiency of Common Storage Houses for Apples 



By F. W. Allen, Assistant Horticulturist Fruit Storage Investigations, Bureau 6f Markets, U. S. Department of Agriculture 



AS prerequisites for success in stor- 

 ing fruit of any kind, whether in 

 cold or common storage, it should 

 be sufficient only to mention the neces- 

 sity of having good fruit, well grown, 

 picked at the proper stage of maturity, 

 carefully handled and stored as soon 

 after picking as possible. With the im- 

 portance of these fundamental factors 

 fully appreciated, the efficiency of air- 

 cooled storages depends directly upon 

 three things: The location of the house, 

 its construction, and the way in which 

 it is managed. 



The terms "air-cooled" and "common" 

 storage are synonymous, but in using 

 the former we imply the medium by 

 which the fruit is cooled. In this type 

 of house there is no artificial means of 

 refrigeration, only the natural circula- 

 tion of air. The cooler the air as com- 

 pared with the temperature of the house 

 the faster the circulation and the more 

 rapid the cooling. In most of the apple 

 sections of the Northwest the nights are 

 generally quite cool, even though the 

 days are warm. Any section having 

 these cool nights is well adapted for 

 successful air-cooled storages. In local- 

 ities where the days are warm, with 

 little reduction in the night temperature 

 until quite late in the fall, the value of 

 the storage is considerably reduced. In 

 fact, the construction of this type of 

 house in such regions should probably 

 be looked upon with some discourage- 

 ment. 



In planning a common storage we 

 should never lose sight of the fact that 

 the building is to be cooled entirely by 

 air circulation. A few small windows 

 located here and there where they will 

 fit in most conveniently will not accom- 

 plish the purpose intended. Air circu- 



lation is induced by the difference in 

 weight of air at different temperatures. 

 The weight of a cubic foot of warm air 

 is less than a cubic foot of cold air. 

 Warm air therefore seeks the higher 

 level and cold air the lower. For this 

 reason intake air vents should be placed 

 in the foundation wall, in order that the 

 cold air may enter at the lowest point. 

 After being drawn into the house this 

 cool air expands, its weight becomes 

 lighter, and with the continuous flow 

 of cold air through the intakes it seeks 





Interior view of air ducts to a basement where 

 the air inlet is built in the wall. With the 

 intake doors on the outside at the level of the 

 ground the cold air is delivered under the 

 false floor. 



an outlet through vents or an air shaft 

 in the ceiling. The storage room floor 

 should be not less than eighteen inches 

 above the ground level and of open 

 construction. Two by fours or two by 

 sixes spaced three-fourths of an inch 

 apart are recommendel. 



With this construction the ventilating 

 system may be compared to a heating 

 stove, where the cold air is taken in 

 under the grate and the heated air 

 passes up and out through the chimney. 

 If we desire more heat, the stove is 

 given more draft, that is, the intake 

 openings are made larger. In order to 

 cool the fruit in an air storage more 

 rapidly, we do the same thing. The 

 same principle applies, only the differ- 

 ence between the temperature of the in- 

 take and outlet air in the storage house 

 is much less than that in a stove, conse- 

 quently the circulation is much slower. 

 For this reason the air vents must be 

 numerous and of proper size. Eighteen 

 by thirty inches is none too large and 

 one such opening should be provided 

 for every ten or fifteen feet on both 

 sides and ends of the house. In ex- 

 tremely large buildings inlet openings 

 should be twenty-four by thirty-six 

 inches. The insulated or refrigerator 

 type of door is much better than those 

 made of only one or two layers of 

 boards. 



The flues or outlet ventilators should 

 lead up from the ceiling of the storage 

 room and out through the ridge of the 

 house. By making these from four to 

 six feet square only one or two such 

 outlets should be necessary for the aver- 

 age individual grower's house. As in 

 the case of the inlets, these should be 

 likewise fitted with trap doors in the 

 ceiling of the storage room. By install- 



