ANNUAL REPORT, 1939 89 



fruit drop. Potassium tests made on leaf petioles showed plenty of this element 

 present. A very limited chemical analysis showed a relatively high percentage 

 of total nitrogen in the fruiting spurs on these trees. 



Much of these new data seems to support the evidence from field experiments 

 previously reported, that a high state of fertility, especially in relation to nitrogen, 

 tends to increase pre-harvest fruit dropping. 



A so-called growth substance, alpha naphthylacetamide, was used to test its 

 effect on delaying normal Mcintosh drop. On September 13, 200 gallons of a 

 .00025 percent solution of the chemical in water were made up in a spray tank 

 and the spray applied to alternate trees in two blocks at the usual pressures 

 (300-400 lbs.). The results were largely inconclusive, although in several cases the 

 evidence pointed to a beneficial effect. It is possible that different concentra- 

 tions and times of application may prove to be of significance. Further work is 

 planned for next year. (See photograph on page 53.) 



Sun Coloring of Apples. (O. C. Roberts.) Mcintosh apples with to 10 

 percent color were placed in a frame covered with three layers of cheesecloth on 

 September 13. They were removed from the frame after exposure to approx- 

 imately 80 hours of bright sunshine and were not turned during exposure. When 

 gathered the average color had increased to approximately 60 percent. None 

 of the apples showed sun scald. The quality of the color was duller and somewhat 

 less attractive than on apples which were allowed to color normally. 



Ten bushels of Wealthy apples, selected at time of picking for lack of colora- 

 tion, were spread on a hay mulch underneath a Wealthy tree with dense foliage. 

 After ten days the color had increased from less than 5 percent to more than 50 

 percent on the surfaces exposed to this indirect light. The under-surfaces did 

 not show any color changes. The flesh texture became noticeably less firm but 

 not enough to adversely affect market value. 



DEPARTMENT OF POULTRY HUSBANDRY 

 R. T. Parkhurst in Charge 



Broodiness in Poultry. (F. A. Hays.) This project has three primary objec- 

 tives: (1) To secure more data on the inheritance of degrees of broodiness, (2) To 

 study the phases of deferred broodiness, (3) To determine whether a genetically 

 non-broody line of Rhode Island Reds is possible. 



The generation hatched in 1938 completed its first laying year in November 

 1939. This generation came from two sires that were 36 months of age and one 

 sire that was 24 months of age in 1938. The matings gave 38 daughters with 

 complete trapnest records from nine non-broody dams. No daughters gave any 

 manifestation of broodiness in the first laying year. A considerable number of 

 these daughters is being retained for a trapnest record during the second laying 

 year to check on deferred broodiness. Males are constantly being checked 

 genetically for the presence or absence of genes for broodiness. 



A Genetic Study of Rhode Island Red Color. (F. A. Hays.) A line of birds 

 from an exhibition foundation is being carried forward to study the genetic 

 relationships between plumage color and characters affecting fecundity. The 

 stock is now in the eleventh generation. The data suggest that there may be 

 certain adverse physiological relationships between genes for exhibition color 

 and genes for high fecundity. Data are also being secured on the mode of in- 

 heritance of exhibition plumage color. 



