114 Report of the Botanist of tub 



on the radish. 



(Raphanus sativus.) 



In the winter of 189S diseased radish plants of marketable size 

 were received from Saratoga, N. Y. The disease consisted of a 

 soft rot of the crown, or of large ulcerations in this region. As 

 a rule, the leaves were unaffected until a considerable portion of 

 the root had decayed. It was reported, however, that plants in 

 all stages of growth were affected and killed. It proved to be a 

 trouble of considerable importance with forced radishes, and 

 nearly half of the crop was lost from this disease. It spread 

 rapidly from plant to plant in the row, and from well-established 

 centers of infection. When the material was received, the tis- 

 sues surrounding diseased areas were infested with hYplrne of a 

 Rhizoctonia. These hyphse were also very abundant superficially, 

 growth being induced, perhaps, by the moist conditions under 

 which the plants had been kept. A culture of the fungus was 

 secured, and with half-grown ladishes'kept imder moist condi- 

 tions the disease was induced; but only a few plants were involved 

 in this experiment. Unfortunately, this culture was afterwards 

 lost, and it has not since been observed as a disease of mature 

 plants. Nevertheless, Rhizoctonia has been found occasionally in 

 the greenhouse as a radish damping-off fungus of slight import- 

 ance. 



ON THE RHUBARB. 



{Rheum rhaponticum.) 



For several years a peculiar disease of rhubarb has been 

 observed on Long Island; but until the past season no satisfac- 

 tory cause of the ti'ouble was evident. During July several 

 rhubarb fields were visited in the vicinity of Jamaica, and in 

 many of these the leaves were dying rapidly, the plants being 

 in an unthrifty condition. There was little or no injury due to 

 the leaf-spot fungus Phyllosticta rJiei, and the trouble was evi- 

 dently of other origin. Affected leaves became dried and 

 shrunken in appearance, and soon fell to the ground. Where a 

 field was badly affected, the majority of hills would show the 



