EXPERIMENT STATION BULLETINS. 279 



There was no drying or shriveling of the leaves and in two days the plant was 

 dead. A microscopic examination of a cross section of the vine and larger roots 

 showed the vascular bundles to be plugged with bacteria. No fungi were found 

 and there was no indication of insect work on the roots. 



The writer has observed the same wilt on the muskmellon. The symptoms 

 here are the same as for the cucumber as are also the symptoms for the squash; 

 sudden wilting as from lack of water caused by the clogging of the watertubes, 

 followed by prostration and death. Usually one runner will die at a time, be- 

 ginning at the tip and working back toward the root. Growers seem to think 

 the wilt is worse during wet weather and just after a heavy rain, especially if 

 the sun comes out very hot. Spraying is useless and preventative measures sug- 

 gest pulling up the sick vines and burning them. The suggestions given for the 

 prevention of potato blight will apply here also. Plant on new land as far as 

 possible and avoid the use of fields which have shown the infection. Rotation of 

 crops is also advised. 



Smith* ascribes the wilt to a bacillusf which he believes is carried from 

 diseased to healthy plants by the cucumber beetle and squash bug, hence the 

 necessity of destroying these insects. 



SOFT ROT OF THE SUGAR BEET. 



This disease was first described and the specific germt isolated by Metcalf 

 and Hedgcock§ in 1902. Beets affected with the rot show the lower half badly 

 decayed and the rotten part honeycombed with "pockets" or cavities filled with 

 a slimy, stringy fluid, colorless and sour smelling. The vascular bundles remain 

 intact while the tissue surrounding them is usually consumed. The normal color 

 of the beets differs so that it is diflBcult to give any hard and fast color char- 

 acteristic, but when affected the tissue first shows a yellow, changing to a clay 

 color or gray; later these colors gradually darken. In some cases beets that are 

 badly rotted show no discoloration while others in the early stages are very 

 dark. Above ground the beets appear normal. 



A microscopic examination of viscid liquid that fills the cavities of the rotting 

 tissue shows millions of bacteria, which when grown later in pure culture and 

 inoculated into healthy beets produced symptoms typical of the disease. 



The germs gain entrance into the beet through wounds and abrasions in the 

 skin and there is good reason for believing that nematodes are responsible for 

 many of the inoculations. So far as experimental work goes, there is no evi- 

 dence that infection can take place except through cuts or scratches in the outer 

 surface of the root. In the field, the disease has been observed to progress most 

 rapidly under warm and wet conditions; more mature beets are affected more 

 severely than the younger ones, probably due to the larger amount of sugar 

 present. 



If the beets are stored in silos and rotting sets in, they should all be inspeated 

 and the decayed ones put in a pile by themselves so that all will not contract 

 the rot. Cold storage does not seem to have any influence on checking the trouble, 

 for even at low temperatures the germs continue to grow and produce havoc. 

 It is recommended 1 1 that beets from sick soil be thoroughly sunned and dried 

 before storing, inasmuch as the desiccation and sunlight have been found to be 

 very detrimental to the growth of the germs. 



Prevention is the only remedy that can be suggested at this time. Grow your 

 beets on relatively dry ground, if possible and plant corn or some other suitable 

 crop on your former beet ground where the excess of moisture can do no harm. 

 Our greatest hope of controlling this disease as well as others is by breeding up 

 some resistant variety and by careful selections secure a strain which can be 

 planted on wet land and yet remain immune. There is no question but that such 

 resistant varieties will be forthcoming in the near future now that the scientific 

 world is so wide awake to the wonders of plant breeding. 



* Proc. Am. Asso. Ad. Sci., 1895, pp. 190. 



i Bacillus tracheiphilus (Smith). 

 Bacillus teutlium (Metcalf). 

 Seventh Annual Report. Neb. Exp. Sta. (1904). 

 Cent. f. Bakt. II Ab. Bd.VII.— 1 & 2. 



