EXPERIMENT STATION BULLETIN'S. 307 



variety, and in many cases considerably more. In New York, Professor 

 Donald Reddick hais tested several strains of Robust and found them 

 to be immune to the Mosaic disease. It seems that resistance to Mosaic 

 is very important in New York State as the bean industry was in danger 

 of being destroyed by the disease. It is yielding fully as well for them 

 as for us. 



In Iowa the test was made in connection -with a soybean variety series, 

 a number of common beans being included. Ove Jensou, the experimenter, 

 reported that the Robust produced four times as much as any other com- 

 mon variety in the season of 1917. 



During the same year, G. W. Putnam obtained good results at Delevan, 

 Kansas. In short the Robust is a higli producing, disease and heat resist- 

 ant variety of white navy bean that should be given a fair trial in every 

 bean section in Michigan. 



This bean, according to reports is becoming a standard in New York 

 and some portions of tlie middle west. 



SELECTION AND CROSSING. 



Beginning in 1007, plant selections were made from new commercial 

 varieties almost annuallv, until in 1917 there were 173 commercial sources 

 of seed that had thus been included in the work. Mosaic was bad among 

 the beans in 190S, causing a large number of plauts to fail to set pods. 

 Only productive plants were saved for future plantings. It was also clear 

 in 1909 that many lots of beans were mixtures of early and late strains 

 as they came to the Station. 



Some crosses were obtained in 1912, Avhich began to segregate in 1914, 

 and out of these icrosses originated a confusion of types in the years that 

 followed up to 1918, when 200 individual plant selections from these 

 beans were included in the plant-row series. Two graduate students 

 wrote theses on these beans during the years 1914 to 1917. 



A new lot of crosses were made by G. W. I'utuam in the winter of 191G- 

 17. These new crosses began to segregate in 1918, and have been exten- 

 sively planted and selected during the years 1919-1920. Ont of this work 

 it is expected that a white na\'y bean may be obtained that is immune to 

 anthracnose as well as mosaic, bnt this work must continue a few more 

 years before such a bean can come true to type and be given a yield test. 



In 1918 several hundred individual plant selections were made in 

 farmers' fields, widely scattered over Michigan. From these new acces- 

 sions, about 200 plaiit rows were planted in 1919. The better yielding 

 strains Avere increased in 1920 so as to enter a new varietal series, be- 

 ginning 1921. 



YIELD TESTING. 



Table I shows the results of varietal testing during the years of 1912 

 and 1914. The Robust (No. 81302) was used as a check, being planted 

 each fifth plant inside of edges. A plat consisted of two rows, each 637 

 feet long and 28 inches apart. At harvest time the puller put the two 

 rows into one. The thi-eshing was done carefully to prevent varieties 

 from mixing and to obtain all the seed. 



