ANNUAL REPORT, 1946-47 65 



times, at different concentrations, and at different rates of application. It was 

 found that ammonium sulfamate at % pound per gallon or the chlorate mixture 

 at l}i pounds per gallon, used at the rate of 1 gallon per 100 square feet, did a 

 95 to 100 percent job of killing the witch grass. In the summer of 1947 it was 

 observed that the witch grass came back into the plots from around the edges 

 faster in the ammonium sulfamate plots than in the chlorate mixture plots. 



A butyl and a methyl ester formulation of 2,4-D were tried on chokecherry at 

 1,000 p. p.m. and at 2,000 p. p.m. in August, 1946. The materials were equally 

 effective, and single was as good as double strength. Growth of the treated 

 bushes was very weak and very abnormal in 1947. Leaves were very narrow, 

 curled, very sharply serrated, and mottled. Fruiting stems made an abnormally 

 vigorous growth but died without producing fruit. 



DEPARTMENT OF POULTRY HUSBANDRY 

 F. P. Jeffrey in Charge 



Broodiness in Poultry. (F. A. Hays and Ruby Sanborn.) Selective breeding 

 has not been successful in entirely eliminating the broody instinct in Rhode Island 

 Reds. A limited life span particularly in males, no manifestation of the character 

 in males, and incomplete progeny testing because of deferred broodiness offer 

 many difficulties. The fact has been clearly demonstrated that broodiness de- 

 pends upon two dominant complementary genes and that quantitative factors 

 affecting the degree of broodiness are in operation. There is a definite linkage 

 between broody genes and intensity of laying, and clucking without cessation of 

 laying has4Deen shown to indicate broody inheritance. Females should be tested 

 for at least three laying years to discover their phenotype for the broody instinct. 

 The last generation to complete its first laying year exhibited no broodiness in 

 the daughters of one 36-month-old sire; but the other sire, 24 months old, gave 

 one broody daughter from a hen of the same age. These daughters are being 

 retained for a further performance record. 



The Effectiveness of Selective Breeding to Reduce Mortality in Rhode Island 

 Reds. (Regional Poultry Research Laboratory and Departments of Veterinary 

 Science and Poultry Husbandry, Massachusetts Agricultural Experiment Sta- 

 tion, cooperating.) Results of breeding high and low mortality lines through 

 three generations were completed in November 1946. The two lines differed 

 significantly in mortality rates to eight weeks, from eight weeks to six months, 

 and from six to eighteen months in both sexes. The low mortality line exhibited 

 a higher mortality rate than the control line during the same period. Complete 

 data are ready for publication. 



Genetic Laws Governing the Inheritance of High Fecundity in the Domestic 



Fowl. (F. A. Hays and Ruby Sanborn.) A number of phases of the problem of 

 breeding for high fecundity have been studied. The value of egg records as a 

 criterion for selecting breeding females was reported in Poultry Science for Novem- 

 ber 1946. The accuracy of limited trapnesting has been investigated and results 

 reported in Station Bulletin 438. Further consideration has been given the prob- 

 lem of intensity, particularly from the inheritance standpoint, and the report is 

 being published as a Station bulletin. The data point to the importance of her- 

 edity in deve'oping high intensity. There is no evidence of sex-linked genes being 



