19171 HORTICULTUEB. 449 



at picking time anyway and partly because it takes much longer and costs 

 more In sorting to pick out the larger amount of unsalable culls from the 

 unthinned trees. 



The results of other investigators dealing with thinning apples are cited 

 and a bibliography on the subject appended. 



Inheritance of sex in Vitis rotundifolia, L. R. Detjen (North Carolina Sta. 

 Tech. Bill. 12 (1917), pp. 5-4S, Jigs. 57).— This is the fourth report on the sta- 

 tion's investigations of T'. rotundifolia (E. S. R., 31, p. 636), and deals specifi- 

 cally with the problems of transmission of sex. The important results secured 

 in the work are summarized as follows : 



" Hope, llio first discovered hermaphrodite grapevine of the species V. 

 rotundifolia. which bears upright stamens, Is self-fertile. The self-fertility of 

 the Hope vine is variable, and seems to depend on its inner constitution. 



" Floral types in V. rotundifolia are transmitted to the progeny in definite 

 ratios. Substituting S for stamiuate flowers, R for hermaphrodite flowers 

 with reflexed stamens, and U for hermaphrodite flowers with upright stamens, 

 we find that 



RXS=1 /?:1.06 S. 

 RXU=1.07 R.l U. 

 UXV=S : R (ratios not determined). 



" The Hope vine and some of its self-fertile progeny apparently will not 

 cross with staminate vines. In V. rotundifolia the upright stamen in herma- 

 phodite flowers is correlated with normal, viable pollen and self-ferility ; the 

 reflexed stamen in hermaphrodite flowers is always associated with defective 

 pollen and self-fertility. The Hope vine and all of its seedlings, which bear 

 upright stamens, appear and behave essentially like staminate vines except 

 for the facts that the flowers usually contain well-developed pistils and that 

 fruit is subsequently produced. The Hope vine probably is a staminate vine 

 whose long suppressed pistils have suddenly been regenerated and have 

 recovered the power to function. The prototype of our present-day rotundifolia 

 vines probably was a true and functioning hermaphrodite." 



Breeding southem grapes, L. R. Detjen (Jour. Heredity, 8 (1917), No. 6, 

 pp. 252-258. figs. Jf ) . — A popular discussion of this subject based upon the above 

 noted investigation. 



The use of commercial fertilizers in growing roses, F. W. Muncie (Illinois 

 Sta. Bui. 196 (1917), pp. 511-564, fidS. 37; abs. ed., pp. ^).— This bulletin de- 

 scribes in detail experiments with dried blood, acid phosphate, and potassium 

 sulphate used in growing Killarney. Bride, and Richmond roses in the green- 

 house during the period 1910 to 1913. These fertilizers were used both alone 

 and in various combinations. Supplementary experiments were conducted dur- 

 ing the period 1913 to 1915 to determine the value of acid phosphate with and 

 without lime as a rose fertilizer. The results secured are presented in tabular 

 form, also illustrated by a series of curves, and fully discussed. 



Summarizing the experiments as a whole it was found that for the soil used 

 at the station, a brown silt loam, fertilization is necessary to produce a maxi- 

 mum crop of roses. The benefit from fertilizing was in number of flowers pro- 

 duced and to a slight extent in the average stem length, though not in per- 

 centage of long-stemmed flowers. No measurable change in length of petals 

 followed fertilization with acid phosphate, but applications of phosphatic fer- 

 tilizer gave the most pronounced increase in the production of roses. Twenty 

 lbs. of acid phosphate per 100 sq. ft. of bench space gave a profit of $176 per 

 1,000 plants. Four times this quantity may be used without injury from over- 

 feeding. The beneficial effect of acid phosphate was continuous throughout 

 the year. 



