UNITED STATES DEPARTMENT OF AGRICULTURE 
| BULLETIN No. 629 
Contribution from the Bureau of Plant Industry <J 
WM. A. TAYLOR, Chief sBQP^Zru 
Washington, D. C. PROFESSIONAL PAPER February 11, 1918 
GREENHOUSE EXPERIMENTS ON THE RUST 
RESISTANCE OF OAT VARIETIES. 1 
By John H. Pabker, 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 avenae 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 
