288 



15ACTERIAL DISEASES OF PLANTS 



various organs are most susceptible during early stages of 

 growth. The beans should be planted 6 or 8 weeks before they 

 are needed and must be shifted occasionally if the pots are 

 small, so that they will continue to develop rapidly. It is best 

 to plant them in 6-inch pots, shifting to 8-inch or 10-inch pots 



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Fig. 221. Fig. 222. 



Fig. 221. — Enlarged base of a bean pod showing translucent exudate, due 

 to Bacterium phaseoli. Pod received from Idaho in 1914. The organism isolated 

 from it served for a long series of infections. It is still infectious (1920). 



Fig. 222. — Bacterium phaseoli on bean. Same series of stomatal infections 

 as Fig. 220, but later. Spots now large, somewhat depressed and exuding bacteria 

 freelj' from their center. Time, 19 days. 



as they require it. They are very easy to grow and need only 

 ordinary care. There may be 2 to 4 plants in a pot, if plenty of 

 good soil is used. 



The inoculations should be both by needle puncture and by 

 spraying since the disease is readily transmitted through the 



