HOETICULTURE. 539 



grapes, and germinating wheat are then reported, together with a study of the 

 metabolism and l^eeping quality of various fruits in nitrogen, hydrogen, carbon 

 dioxid, and air. 



The author's studies as a whole are summarized as follows : " The respira- 

 tion of ripe fruits, as well as that of green fruits, is rapid. The anaerobic 

 production of carbon dioxid by ripe cherries, blackberries, and grapes is as 

 rapid as the aerobic production for a considerable length of time. Ripe fruits 

 that spoil quickly, such as cherries, have a higher respiratory rate than those 

 that do not spoil so quickly, such as grapes. This is due, possibly, to a higher 

 enzym content. 



" Fruit tissues that respire as actively anaerobically as aerobically seem to be 

 those that have finished their growth and are ripe. Growing tissues, such as 

 green peaches and germinating wheat, respire more than twice as rapidly aero- 

 bically as anaerobically. The activity of the protoplasm would seem to be 

 connected with this more direct use of oxygen in the production of carbon dioxid. 

 If growing tissues, such as green peaches, are placed in an oxygen-free gas for 

 a few days and then brought back into air, the rate of production of carbon 

 dioxid does not entirely return to the normal. This would indicate a permanent 

 injuiy to the protoplasm or to some of the enzyms, due to insufficient oxygen. 



" Ripe apples lose their color, texture, and flavor, and take on the qualities 

 of half-baked apples by being kept for a sufficient length of time in oxygen-free 

 gases. This emphasizes the need of good aeration for apple. The softening of 

 peaches seems to be decreased greatly by carbon dioxid and to a considerable 

 extent by hydrogen and nitrogen. Peaches become brownish and acquire a very 

 bad flavor when oxygen is withheld from them. ' Ice scald ' seems to be injury 

 due to insufficient oxygen and to an accumulation of carbon dioxid within the 

 paper wrappers in which peaches are so often shipped. With good ventilation 

 in conjunction with good refrigeration such injury may be greatly reduced. This 

 applies to fruits in storage as well as to those in transit. Good ventilation in 

 conjunction with refrigeration is of prime importance for the successful storage 

 of fruit." 



A bibliography of cited literature is appended. 



The application of nitrogen in relation to fruit-bud formation, T. Remy 

 (Mitt. Deut. Landw. Gesell., 28 (191S), No. 29, pp. 416-',21, figs. 5).— In connec- 

 tion with a study of the relations existing between fertilizers applied to fruit 

 trees and the nutritive content of the various organs of the trees, studies were 

 conducted with dwarf pears and apples during the period 1907-1911. One row 

 of trees received a complete fertilizer. In other rows nitrogen, potash, phos- 

 phoric acid, and lime, respectively, were withheld. In the case of pears an un- 

 fertilized row was also included. 



Observations, as made for each season, indicate that the application of a 

 certain amount of nitrogen is necessary for the abundant development of fruit 

 buds. An analytic study of the dry substance of the leaves shows a perceptible 

 relation between the nitrogen content of the leaves and the amount of nitrogen 

 applied to fruit trees. Although this relation was somewhat variable, results 

 indicate that with both pears and apples a nitrogen content of less than 1.25 

 per cent of the dry substance of the leaves during the fruit ripening period is 

 insufficient for the abundant setting of fruit buds. The ratios between the 

 various nutritive elements appear to exert some influence on fruit-bud develop- 

 ment, although this influence can not be shown. In the rows where nitrogen 

 was withheld the phosphoric acid content of the leaves was higher. 



Although in the present experiments no relations were detected between the 

 amounts of potash, phosphoric acid, and lime applied and the amounts of these 

 163S5"— No. 6-^13 4 



