202 BACTERIA IN RELATION TO PLANT DISEASES. 



until rainy weather has set in. The cardinal rules should be: Dig early, dry thoroughly, 

 store in a cool, dry place after removing all suspicious-looking tubers, and use as soon as pos- 

 sible. The crop can not rot from this disease if stored at 8 C. (46 + F) or under. 



Moist land should be underdrained or planted to other crops. Tomatoes and other 

 plants subject to the disease should either be germinated where they are to stand or else 

 transplanted quite young and with the greatest care to avoid crushing or breaking the roots. 

 Seedlings having the galls of eel-worms on their roots should be rejected; also over- grown 

 seedlings, the latter because their roots are likely to be broken in transplanting. 



To recapitulate : Inspect tubers at the stem-end by cutting some days before planting and reject 

 all that show any trace of this disease. If possible procure seed tubers from localities where this 

 disease does not occur. Plant on land not infected by this organism. If infected land must be 

 used, select that not subject to root-nematodes, and in transplanting seedlings to such land do it 

 early in their growth, and break the roots as little as possible. Practice rotation, but not of one 

 susceptible species after another. Drain the moister portions of the field. Burn over or steam 

 the soil selected for a seed bed. Potatoes grown on infected land shoidd be sold in the summer or 

 autumn, and always stored in a cool dry place. Destroy insect enemies. Be on the lookout 

 for resistant varieties. Read what is said under "Wilt-Diseases of Tobacco" (p. 238). 



PECUNIARY LOSSES. 



This disease has destroyed a great many fields of tomatoes and potatoes in the South, 

 and has put an end to commercial tomato-growing in certain sections, e. g., southern Missis- 

 sippi, southern Alabama, and parts of Florida. 



The following letter, dated May 25, 1905, from a tomato grower in North Florida, is 

 like many others received by the U. S. Department of Agriculture from various parts of the 

 South in recent years: 



Under separate cover I send you a diseased tomato plant. 



Out of a crop of 30,000 plants I have lost fully one-third, and many more seem to be becoming 

 affected. 



The first thing noticeable is the tender tips of the plant wilting, but nothing can be seen outwardly 

 or even by cutting into the plant at the top, but by cutting into the roots, or stem, for a short distance 

 above the ground, the wood immediately under the bark and the interior of the roots are found to be 

 discolored and bad. The disease has spread with great rapidity during the past few weeks and is 

 still increasing, and it seems about to wipe out the entire crop. 



It is not confined to any one field and is equally distributed on soils of widely different character, 

 some of it high, light, and some of it low, black soil. Also, the disease is equally distributed on fields 

 where tomatoes were never grown till this year. 



Another man writes as follows under date of May 16, 1903, respecting this disease: 



Our truck farmers around this section, Tyler, Texas, who have hundreds of acres of tomatoes, 

 are complaining that the blight is destroying some of their fields, thus entailing a loss of thousands of 

 dollars. 



( )ne planter at Norfolk, Virginia, lost 3,000 barrels of potatoes by this rot in 1908. 



Additional statements respecting losses may be found in the chapter dealing with the 

 history of this disease. 



If Bad. solanacearum also plays any considerable part in the frequent and widespread 

 outbreaks of potato-rot in the northern United States, as now seems likely, but has not 

 been proved, then the annual losses can be reckoned only by hundreds of thousands of 

 dollars. The northern distribution of this organism is unknown. 



The subject of potato-rots is still surrounded with a good deal of uncertainty. The 

 fungus Phytophthora infestans undoubtedly causes great losses in the cool, moist regions of 

 Europe and occasionally in the more northern parts of this country, where the writer has seen 



