

UNITED STATES DEPARTMENT OF AGRICULTURE 



i BULLETIN No. 629 & 



Contribution from the Bureau of Plant Industry •; 



WM. A. TAYLOR, Chief JO&*^&U 



Washington, D. C. PROFESSIONAL PAPER February 11, 1918 



GREENHOUSE EXPERIMENTS ON THE RUST 

 RESISTANCE OF OAT VARIETIES. 1 



By John H. Parker, formerly Scientific Assistant, Office of Cereal Investigations. 



CONTENTS. 



Page. 



Introduction 1 



The culture of cereal rusts in the green- 

 house 2 



Experimental methods 2 



Sources of material 5 



Page. 



Evidences of rust resistance in cereals 5 



Experimental data 8 



Discussion of results 13 



Summary and conclusions 14 



Literature cited 16 



INTRODUCTION. 



The rusts have long been recognized as one of the most serious 

 limiting factors in the production of wheat and oats, both in the 

 United States and in other countries. Considerable work has been 

 done on the problem of controlling rust in wheat through resistant 

 varieties and some results have been published, but very little specific 

 information has been made available on the rust resistance of oat 

 varieties in the United States. 



The importance of the oat crop among the small grains in the 

 United States is second only to that of wheat, and the problem of 

 rust control is perhaps even more acute, for oats are more widely 

 grown in localities favorable to rusts. For this reason a proper 

 choice of varieties, based on accurate experimental tests, is a neces- 

 sary factor in successful oat culture. The present paper presents the 

 results obtained in greenhouse culture work with the crown rust of 

 oats, Puccinia lolii avenue McAlpine (PL I, fig. 2, and PL II), and 



1 The work here described was a part of the graduate studies of the writer during the 

 college year 1915—16 at Cornell University and was a continuation of investigations 

 conducted for several years while in the United States Department of Agriculture. The 

 departments of plant breeding and plant pathology in the university provided every 

 facility for the work, which was carried out under the supervision of Dr. H. H. Love, 

 to whom thanks are due for many helpful suggestions. 

 16710°— 18— Bull. 629 



