238 EXPERIMENT STATION RECORD. 



Both are improvements over the limes usually grown in Florida. The varie- 

 ties of pineapple have ))een called Miami. Seminole, Eden, Matthams, and Gale. 

 Illustrated descriptions are given of each, with an account of its origin. All 

 are remarkable for their superior flavor. 



Promising' new fruits, W. A. Taylor (U. *S'. Dept. Agr. Yearbook 1905, pp. 

 ■'f95--jlO, pis. 9). — Historical notes and illustrated descriptions are given of the 

 Virginia Beauty and Carson apples; Crocker pear; Everbearing peach; Golden 

 plum ; Riley, Scioto, and Pringle Damson plums ; Eulalia loquat, Hollis, Money- 

 maker, Schley, and Success pecans, and Trapp avocado. 



The relation of early maturity to hardiness in trees, R. A. Emerson (A^e- 

 7^/-a.s7,-« .S7a. Rpt. 1905, pp. 101-110, fir/s. 13). — The author states "that resistance 

 to cold in trees Is due often almost wholly to the habit of early maturity rather 

 than to constitutional hardiness." That early maturity and hardiness is in a 

 large measure a matter of variety is brought out in a number of illustrations 

 showing the difference of maturity in fall of different varieties of plums and 

 apples. Young trees also grow longer in the fall than old trees, as a consequence 

 of which the wood is less matured and the trees are more subject to injury from 

 cold than older trees. 



Data and illustrations are given for black walnut and honey locust trees, show- 

 ing that trees grown from seed from a southern locality grow longer in the fall 

 and enter the winter in a more sappy and green condition than the trees grown 

 from seed obtained farther north. The hardiest trees of black walnut were 

 grown from seed obtained from South Dakota.' Natural late growing trees can 

 be forced into early ripening by planting on high land instead of low ground 

 and by the use of cover crops planted in midsuunner, which dry out the gi'ound 

 enough to check growth of the trees and thus force them to ripen their wood 

 before winter. By the use of cover crops late growing varieties were made to 

 stop growth from a few weeks to 2 months earlier than similar trees in adjoin- 

 ing plats given late cultivation. 



Conditions which affect the time of the annual flowering of fruit trees, 

 E. P. Sandsten ( Wisconsin Sta. Bui. 137, pp. 21 ) . — The author made a study of 

 the interrelation of climatic conditions to the time of flowering of a number of 

 orchard fruits. Tabular data are given showing the blooming period for the 

 years 1899-19t»5 of 20 varieties of plums and 25 of apples, and of the principal 

 climatic features during each of these years. 



It has been held that a definite number of heat or temperature units are re- 

 (luired for a given species to come into bloom, and this has been termed its 

 " physiological constant." The author shows that the relation between tempera- 

 ture and time of flowering of apples and plums in different years is too wide and 

 variable to be used as a basis for calculating a physiological constant, especially 

 if the spring temperature only is considered: In 1902 plums did not bloom until 

 the average of 762 positive heat units had been received in the spring, while in 

 1901 they bloomed after receiving but 601 units. If. however, the positive tem- 

 perature unit lie reckoned from the preceding .Inly — a period covering the entire 

 development of the flower bud — instead of January, it is shown that the flower 

 buds of 1901 received a total of 4,487 units, or 450 to 500 more than the flower 

 buds of 1902 received. 



A number of factors other than temperature were also found to influence the 

 time of blooming. A heavy fruit crop retards the development of flower buds 

 and delays blossoming. The distribution of the heat and rainfall during the 

 growing season, soil conditions, and health of the trees are also factors. If these 

 factors are eliminated " it seems reasonable, from the evidence presented [that], 

 a physiological constant can be formulated from the climatic conditions during 

 the 10 months preceding the time of flowering." 



