BOOKS A AW BULLETINS. 



191 



and obscure of the sweet potato diseases. The roots are 

 attacked when young, and the diseased portion ceases to 

 grow, causing the tuber to become constricted or knotty 

 or variously misshapen. The fungus exists in the soil, 

 and attacks plants which are perfectly healthy when set. 

 " From the conditions that surround the growth and pre- 

 servation of this soil rot fungus, it is likely that it cannot 

 be eradicated by any of the ordinary methods of spraying 

 with copper compounds. It is most emphatically in the 

 soil, as every sweet potato grower well knows. With the 



black rot. it has been shown that one of the 

 Soil Rot. great precautions is to have perfectly healthy 



sprouts : but this will avail almost nothing 

 in the case of the soil rot. The infection is by means of 

 the brown spores that are lying in and upon the soil. It 

 might be possible to dip the roots in some substance not 

 injurious to the sprout, that would destroy the germs 

 afterwards coming in contact with the plants. In like 

 manner, it is possible that some substance might be placed 

 in the hills before the plants are set out that would kill 

 the fungus. But the field experiments of the past season 

 with sulphur, lime and various other substances have not 

 demonstrated that any of these are satisfactory remedies. 

 The adoption of a long rotation, so that sweet potatoes 

 come as a crop many years apart, is probably the most 

 practical method of getting the field clean of the destruc- 

 tive soil rot." 



The stem rot attacks the young shoots and the tops of 

 the young tubers, causing them to die and decay. The 

 rot descends for an inch or two into 

 Stem Rot of the tuber, and the diseased tuber 



Sweet Potatoes. sends up young sprouts in the vain 

 effort to renew the plant. Dr. Hal- 

 sted has not yet been able to identify the fungus which 

 causes this disease. The only remedy which he can sug- 

 gest is rotation. 



The white rot causes portions of the tuber to become 

 white and chalk-like. "The trouble is first noticed by 

 the slight depression in the root at the base of one or 

 more of the hairs. These depressions 

 Sweet Potato continue to enlarge and deepen, and in 

 White Rot. bad cases, several may become conflu- 



ent, and finally the whole of the potato 

 is of a chalky consistency and consequently worthless." 

 The fungus causing this disease is not positively identi- 

 fied, and no remedy is suggested 



In the dry rot [^Phoiiia liataice)" the whole upper end of 

 the root becomes dry, much wrinkled, and exhibits upon 

 the surface a multitude of pimples. The whole substance 

 of the potato is diseased, and, with the 

 Dry Rot of exception of certain pits for the pro. 



Sweet Potato. duction of spores, there is very little 

 change of color, while an almost pow- 

 dery condition of the substance has replaced the previous 

 ' juicy tissue of the root, as seen in health. " ' ' As this form 

 of rot is as yet only occasionally met with, there is no 

 cause for alarm from it ; but the fungus nature of the dry 

 or pimply rot being established, it is evident that as a safe 

 preventive, all such decayed potatoes should be destroyed 



and not allowed to remain upon the soil, where the count- 

 less spores may mature and spread the trouble. All pos- 

 sible precautions should be taken in clearing away the 

 rubbish after each crop," 



The sweet potato scurf [Mi'iii/oi/nv/es iuf :isic-?i>) covers 

 the tubers with a rusty coat. "In some soils, nearly 

 every potato will be wholly or in part covered 

 with a scurf, while elsewhere the roots are Sweet 

 free from it. It is quite objectionable, for Potato 

 while not causing the decay of the roots, there Scurf, 

 is a shrinking of the potatoes, and for this 

 reason and the less attractive appearance, the market 

 value of scurfy potatoes is a-half dollar or so per barrel 

 below those that are bright and clean. ' "The scurf is 

 found upon the roots above the potatoes, particularly up- 

 on that portion from which all the potatoes arise. No at- 

 tempts have been made to find a remedy for this trouble. 

 It is likely that the fungus may pass from a scurfy root 

 used for propagation, to the sprouts developed from it, 

 and therefore it is a precaution to use, if possible, roots 

 for the hot-bed that are bright and free from the scurf. 

 It is also possible that some quality of the soil may favor 

 the growth of this dark mould, and when this is known, 

 something may be done to reduce the trouble. Some 

 kinds of manure may favor its development, and it is 

 likely that something could be applied to the freshly-dug 

 potatoes that would check the spread of the scurf." 



The leaf blight (PJiyllosticta bataticola) produces white 

 dead patches upon the leaves, and often seriously injures 

 the plant. It can probably be held in check by spraying 

 with some of the fungicides. The leaf mould (Cyslopiis 

 Ipomirix-paudnrainT) is a serious sweet potato pest. 

 "The affected leaves at first lose their healthful green 

 color, and the paleness is soon fol- 

 lowed by brown patches that after a Leaf Diseases of 

 time become quite dark. Upon the Sweet Potato, 

 under side there may be seen small 



patches of a whitish color. These are places where the 

 leaf-skin has been broken, and multitudes of white fungus 

 spores have formed," The fungus thrives upon a wild 

 morning glory or man-of-the-earth [Ipoiiiaa paiidiirala) 

 which grows in Jersey and southward, and this weed 

 should be destroyed. 



Bulletin No. 24, New York State Experiment Sta- 

 tion. Experiments until Stra-wberries . Pp.. 20. /Ilus- 

 trated. This bulletin records the work of C. E. Hunn, 

 but, although it is written in the first person singular, no 

 name is signed to it. Work of such an important char- 

 acter as the crossing of plants should have the author's 

 name attached to it. 



The bulletin urges the farmers of New York to grow- 

 more strawberries, and it gives a good series of notes 

 upon many varieties. It would have 



been better, however, if more definite Strawberries at 

 and succinct conclusions had been Geneva, H. Y. 



drawn. The best of the newer straw- 

 berries for the farmer's garden are Bomba and Haver- 

 land for early, Burt and Daisy for medium, Crawford 

 and Middlefield for late. "There are several of the 



