64 MASS. EXPERIMENT STATION BULLETIN 417 



Sprays of 1 and 2 pints in 100 gallons applied to peach trees in full bloom 

 were only partially effective. All trees required further hand thinning. The 

 trees showed little injury. 



Killing Poison Ivy. (L. Southwick.) In August 1943, ammonium sulfamate 

 was applied to poison ivy growing under apple trees. With a small power sprayer, 

 approximately 3 gallons of solution were required per large tree to wet thoroughly 

 the rank ivy growth. Concentrations of 3^, ^, and 1 pound of the chemical 

 per gallon of water were apparently effective in killing the ivy foliage. Recovery 

 as of June 1944 is spotty, and the small amount of ivy that is growing does not 

 have a normal or healthy appearance. However, on the basis of previous tests, 

 a partial recovery in the season following applications indicates that additional 

 treatment is required; if omitted, the ivy is very likely to continue to grow and 

 increase. In general, the results seem to indicate that probably % to 1 pound 

 of ammonium sulfamate per gallon of water is an effective spray for poison ivy 

 control. 



The lower limbs of an apple tree were sprayed to observe the extent of injury. 

 The sprayed foliage was killed inside of 24 hours and the killing later extended 

 somewhat back from the sprayed portions. In other words, the chemical was 

 evidently transported a short distance to unsprayed foliage and killed it. Al- 

 though this does not seem to be a serious feature, care should be taken to keep 

 the spray off the foliage of all fruit trees. 



DEPARTMENT OF POULTRY HUSBANDRY 

 R. T. Parkhurst in Charge 



Broodiness in Poultry. (F. A. Hays.) Attempts to establish a line of Rhode 

 Island Reds that do not transmit the broody instinct have been greatly handi- 

 capped by the limited life span of the birds, by deferred broodiness, and by re- 

 stricted numbers. The generation hatched in 1942 included 106 females sired 

 by two 24-months-old males mated to hens with no record of broody manifesta- 

 tion. There was no evidence of broodiness in any of these daughters. The gen- 

 eration hatched in 1943 was also from aged parents and consisted of 81 daughters, 

 which are now in their first laying year. They will be tested for deferred broodi- 

 ness, which is probably the most important obstacle to overcome. 



Effectiveness of Selective Breeding to Reduce Mortality. (Regional Poultry 

 Research Laboratory, and Departments of Veterinary Science and Poultry 

 Husbandry, Massachusetts Agricultural Experiment Station cooperating.) 

 Records have been completed to the age of 18 months on all males and females 

 hatched in 1942; to March 1, 1944 (about 11 months) on the 1943 generation; 

 and to May 1 on the 1944 generation. Mortality rates for the first 6 months were 

 decidedly lower in the low mortality line. Adult mortality from 6 to 18 months 

 was significantly lower for females in the low line. Results for males were dis- 

 torted by excessive cannabalism. The recessive lethal gene reported last j^ear 

 in the high mortality line appeared again in 1944 but to a lesser extent than in 

 1943. 



Data for the 1943 generation from 6 to 11 months of age indicate that the 

 incidence of diseases of the paralysis complex was not high in any of the lines. 

 Cannibalism was the major cause of death; but no reason is evident whj' cannibal- 

 ism should have been so much more prevalent in the high mortality line when 

 birds of all lines were housed together. The data indicate further that selective 



