540 EXPERIMENT STATION RECORD. [Vol.40 





constant, while in that which is frozen it continues to decrease until practically 

 none remains. 



A test of the efficiency of orchard heating, by A. D. Shamel, L. B. Scott, and 

 C. S. Pomeroy (pp. 315-321 ) .—The test here reported was conducted coop- 

 eratively by the U. S. Department of Agriculture with the substation. Follow- 

 ing the freeze of 1913, performance records were kept of comparable plats of 

 trees in heated and unheated lemon groves, beginning with the first pick after 

 the frost and continuing for one year. In two of the plats observations were 

 continued for two years. 



The data here presented indicate that under the conditions of the Corona 

 district, where an unusual number of groves were protected by heaters, orchard 

 heating was highly profitable. The estimated average returns per acre from 

 three series of plats was $1,737.02 for the heated plats and $284.45 for the 

 unheated plats. The average cost of heating per acre of heated plats in the 

 experiments was $101.30. In the second year's data the heated and the un- 

 heated plat also showed considerable difference In production. 



Propagation and culture of the date palm. B. Drvmmokd (V. B. Dcpt. Agr., 

 Farmer? Bui. 1016 (1910), pp. 22, figs. 10).— This discusses the propagation of 

 the date palm, nursery bed practices, transplanting offshoots to permanent 

 positions, winter protection for young date palms, Irrigating the date garden, 

 fertilizing the date garden, soils suitable for date gardens, choice of location 

 of date gardens, pruning date palms, fruit production in relation to offshoot 

 production, and pollination of date palms. 



Investigations with pecans, O. D. Matthews [Wen. Rpt. Comr. Agr. .V. C. 

 1917-18, p. 87).— A brief progress report on Investigations with pecans being 

 conducted at the Truck, Coastal Plain, and Piedmonl stations of the North 

 Carolina Department of Agriculture. 



The work of variety testing has shown the marked adapt ability of certain 

 varieties to North Carolina conditions, while others are proving undesirable. 

 Performance records of individual trees kept at the Beveral stations have shown 

 that trees of the same variety under Identical conditions are uniformly heavy 

 yielders, while others are very poor producers Some trees produce uniformly 

 large nuts and others uniformly small nuts. These results have been used as 

 the basis for hud selection work. 



Correct cultural practices, such as tillage and the use of cover crops, have 

 given good results In the Increased size of troo^ as well as in the Increased size 

 and number of nuts produced when compared to trees grown in sod. 



investigations dealing with the methods of budding and grafting employed in 

 top-working pecan trees have led to the Opinion thai top-working should be con- 

 fined, as a general rule, to trees nol over 8 to 10 years old t<> I otirely suc- 

 cessful. A combination of both grafting and budding lias given the most satis- 

 factory results 



On hybridization of some species of Salix. S. Ikkno {Jour, drmtics, 8 

 (1918), Xo. 1, pp. SS-58, pi". 2. fig. /).— A fuller report of an Investigation pre- 

 viously noted i K. S. R„ 37. p. 432). 



A number of allelomorphlc characters were segregated, but in every case the 

 proportion of individuals hearing each antagonistic character failed to follow 

 the usual Mendelian ratios. It is suggested that a great number of factors are 

 concerned in the development of each character, hence a complex se^'retration 

 takes place in F». 



Chrysanthemums for greenhouse and garden. P. B. Crank [London: W, II. 

 ,f /.. Gottingridffe, tnis. 3. ed., pp. 1SS%, pi*, is. figs. Gi).— The introductory chajt 

 ters of this work deal with the history and classification of greenhouse and 

 border varieties of chrysanthemums. The succeeding chapters discuss various 



