Jan. 1923] annual keport 11 



A preliminary report on Fz has already been published in technical Bul- 

 letin No. 16, but a supplementary and more complete report on the second 

 and third generation offspring will be issued during the coming year. 



The results in wool inheritance have been especially gratifying. There 

 has been no marked evidence toward segregation in the quahty of the wool; 

 about 75 per cent, of the clip has been classed by expert graders as ^-blood 

 staple and nearly all the remainder as 3-8 blood. Only one fleece as low as 

 ^-blood has so far been obtained, and only four fleeces have reverted to the 

 finer Delaine. About 90 per cent, of the fleeces had a sufficient length of 

 staple to sell as combing wool. While the wool approaches Rambouillet 

 quality in fineness, crimp, and length, it carries much less grease than the 

 latter; this fact in a measure accounts for the difference in fleece weights, 

 the average being between 7 and 8 pounds per head. 



Careful periodical weighings of all individual lambs indicate that up to four 

 or five months the rate of growth varies primarily with variation in milk 

 yield of the dam. Consideration of this highly important factor together 

 with that of fecundity has had to be postponed in the past, since the limited 

 number of animals used did not permit selection for a large numberof char- 

 acteristics at one time. 



It is planned, therefore, to continue the sheep breeding project on the 

 Mendelian principle of hybridization as in the past, but to center the main 

 attention on the study of the inheritance of fecundity and higher milk yield. 

 These studies will be timely not only because of their economic importance; 

 the development of the inherited potentialities for growth is dependent 

 on a bountiful milk supply for the young, and this factor, if disregarded, 

 may vitiate the most carefully conducted investigation. 



A Rambouillet ram and twenty-one Oxford ewes have been purchased 

 for this phase of the investigation. The Rambouillet parent was, of course, 

 selected because of the fine wool and heavy fleece. The Oxford females 

 were chosen because ewes of that breed are good milkers, and because they 

 often show high fecundity, and at the same time possess a reasonably good 

 mutton conformation. 



Control of Root Maggots. 



The investigations for the crop season of 1922 conducted by W. -C. O'Kane 

 and P. R. Lowry (Entomology) fully corroborated the results secured in 

 1921 and 1920 and brought this project to the point where further publi- 

 cation is in order, covering the work with the tobacco-dust-Ume mixture. 



Earlier in these investigations, when the studies included a number of 

 different materials, one of the treatqients that gave promising results was 

 a dry mixture of tobacco dust and calcium carbonate. The studies of 1920 

 and 1921 were designed to throw light on the causes lying behind the re- 

 sults obtained with this material. Interesting and important facts were 

 secured as noted in the 1921 report. 



The experiments carried out the past season were in the main parallel 

 to those of the preceding two years. Some new details were brought in, 

 suggested by the results of 1921. The data of 1922 fall closely in line with 

 the results of the preceding two years and show clearly the following: 



