The Dry Root-Rot of the Bean 1019 



was used as a check row, while the other was heavily fertilized with the 

 bean-straw manure. The manure contained decaying pieces of bean 

 stems and roots which had been in the compost heap during the pre- 

 ceding winter. The plots at Ithaca were planted on June 22, 1916, and 

 those at Perry were planted on June 28, 1916. The results of the experi- 

 ment are shown in table 2. 



The few diseased plants appearing in the check rows can be accounted 

 for readily as infections caused by washings from the diseased rows. 

 The fungus also could have been transferred during cultivation. 



Cross-inoculations 



Many inoculation experiments were conducted to find other hosts of 

 Fusarium martii phaseoli. These experiments were conducted both in 

 the greenhouse and in the garden. In all cases rows of beans were inocu- 

 lated with the pathogene as a check. Without exception infection was 

 obtained on the bean. The following plants proved susceptible to F. 

 martii -phaseoli: the tepary bean (Phaseolus acutifolius Gray var. latifolius 

 Freeman), the scarlet runner bean (P. multiflorus Willd.), the adzuki bean 

 (P. angularis Willd.), the moth bean (P. aconitifolius Jacq.), the Black- 

 eye cowpea (Vigna sinensis [L.] Endl.), and the kulti bean (Dolichos 

 biflorus L.). Infection was very light on the scarlet runner and the 

 lima bean. 



Negative results were obtained with a number of legumes and other 

 plants. This list is as follows: the garden pea (Pisum sativum L.); the 

 field pea (P. sativum L. var. arvense Poir.); red clover (Trijolium pratense 

 L.); alsike clover (T. hybridum L.); vetch (Vicia sp.); the following varie- 

 ties of soybeans (Soja max Piper) — Medium Green, Ito San, Auburn, 

 Wilson; corn (Zea mays L.); potato (Solarium tuberosum L.); oats (Avena 

 sativa L.); wheat (Triticum sp.); and the following weeds — Ambrosia 

 artemisiifolia L., Prunella vulgaris L., Chenopodium album L., Rumex sp. 

 The weeds used in the inoculation experiments were those found com- 

 monly in the bean fields. 



EFFECT OF WEATHER CONDITIONS 



In the case of root parasites, infection is not so dependent on weather 

 conditions as with those pathogenes which attack parts of plants above 

 ground. Such factors as sun, wind, rain, and dews are eliminated. 



