Disease Resistance in Beans 13 



of dry-shell bean will be introduced in the fields of New York until it is 

 known to conform to some one of the standard varieties now in cultiva- 

 tion, and even then it is not too much to expect that such a variety would 

 not be accepted by growers unless they were assured that it was as good 

 as or better than the standard, not only in yield and conformity to type, 

 but also in resistance to diseases. 



Further, it is always possible that these hybrids might prove to be re- 

 sistant to the new race. Certain varieties of snap beans always have 

 been grown in close proximity to the hybrids, and some of these always 

 have been sorts that were bought of seedsmen. One year, indeed, the 

 organism was taken from these varieties of unknown origin and was 

 mixed with the three races to make a general inoculation. No attempt 

 was made to determine which races may have occurred on these vari- 

 eties, but it was evident from the behavior of the plants used for check 

 that nothing which could be called certainly new had been introduced. 



OTHER RESISTANT VARIETIES 



Finally, it may be added that in case none of these hybrids proves to 

 be a desirable commercial sort and it seems impossible to secure a de- 

 sirable type by the use of these parents, there exist some other varieties 

 which possess a high degree of resistance to the three races of Colleto- 

 trichum lindemuthianum and which are very tolerant to mosaic. A 

 large number of varieties have been grown for several years in a parallel 

 row with the hybrids, and usually have been inoculated in the field along 

 with the hybrids. 



Nova Scotia Marrow. One of these varieties is in commercial produc- 

 tion at the present time under the name Nova Scotia Marrow. The plant 

 is determinate in growth habit, whereas White Marrow, which is suscep- 

 tible to races beta and gamma, is indeterminate. The dry seed of the 

 two varieties is very nearly of the same size and shape, and is readily 

 interchangeable. An objection to Nova Scotia Marrow is that the cotyle- 

 dons are likely to split apart somewhat, as the seeds dry down in the pod. 

 The operation of threshing separates some of these, and, as a result, the 

 pick- is relatively high. 



Some other varieties which have reacted like the Nova Scotia Marrow, 

 but winch from color or shape of seed do not offer such obvious possi- 

 bilities, are listed herewith. These varieties mostly are not known in 

 the trade and cannot be certainly identified by the use of Jarvis' work 

 (1908). 



Yellow-Eye Navy. A variety was procured from the .John Lewis 

 Childs Company in 1017 as new under the name Yellow-Eye Navy. The 

 seeds a1 preseni approximate Yellow Eye in size and marking, and seem 

 to be larger than when originally procured. 



