DISEASES OF PLANTS. 59 



heijaii in 1S90, and I'oiiliiiued for 5 years^, field experiiuents in which the vahie of 

 sulphur, and sulphur and lime, as soil treatments were testeil. Various amounts 

 of sulphur and sulphur and lime were applied in the drills where the seed was 

 planted, with beneficial results. The best results were obtained where 100 lbs. of 

 suli)hur and 50 lbs. of lime per acre were applied directly to the drills. With this 

 treatment there was an average annual increase of fully 50 per cent in the product 

 on soil that had jireviously given snuitty crops. The apxilication of sulphur and lime, 

 when sown broadcast, was without particular value. It is recommended in the 

 api)lication of lime and sulphur for the prevention of smut that it be drilled in the 

 drills at the same time the seed is sown, and an implement is <lcscrilH-d which was 

 used with success for this juirpose. 



P^xperiments were conducted to ascertain the time wdien the ])lants were infected 

 by the fungus, which showed that they were immune to attacks of the snnit by the 

 time the seedlings reached the surface of the soil. Soaking the seed or coating it 

 with fungicides iHd not prove of any benefit in preventing the disease. 



Sulphur and lime for onion smut, F. H. Hall, F. A. Sirrine, and F. C Stew- 

 .\KT [Xetr York' tStiifr ,^lii. Biil. 1S,\ popuhir I'lL, pp. S). — This is a j)opular smnmary 

 of the above liulletin. 



CrO'wn gall of apple, W. G. Vincenhellek {Arkanmx Sla. Rpt. 1900, pq). 112, 

 IIS). — The occurrence of crown gall on ai)Dle trees in orchard and nursery is men- 

 tioned. Investigations conducted by the author seemed to indicate that grafts made 

 from whole or long roots and short scions are nmch more liable to injury than those 

 made with short roots and longer scions. The short root and long scion placed the 

 union 7 or 8 in. below the surface, and at that depth trees are apparently less subject 

 to attack. The results of experiments with grafting 30 varieties of apples, 200 grafts 

 each, showed that most of the varieties were free from the diseased growth. The 

 author believes that propagating trees by the method suggested, as a means for the 

 pre\cntion of crown gall, is worthy of trial. 



The New York apple-tree canker, W. Paddock [Ncir York tShilc ,St((. Jlnl. 185, 

 jiji. 205-21S, pis. 4) • — This bulletin is the second report on the canker which affects 

 apple trees, being a continuation of the investigations reported in Bulletin Itio of the 

 station ( E. S. R., 12, p. 59). It has been found that any part of the apple tree above 

 ground, with the possible exception of the leaves, is sul)ject to attack by the canker 

 fungus, which has proved to be Spha^ropsis malorum. Wlicn occurring on the limbs 

 or trunks the injuries are known as cankers, and they are often quite conspicuous 

 since the bark becomes thii-k and rough, and saprophytic fungi soon gain a foothold, 

 causing the parts to turn l)lack. The injuries are often several feet in length, and 

 because (jf these striking characters the cankered limbs may be recognized at a con- 

 siderable distance. The fungus can live in the outer bark of the tree where it does 

 but little harm. An affected branch may be girdled by the fungus and saproijhytic 

 fungi complete the work of destruction. When it occurs on new growth the twigs are 

 killed in a manner very much resembling the attack of pear ])light. When the fun- 

 gus oct'urs on the fruit of the apple it produces what is known as black rot, and 

 mnnerous experiments have shown that it occurs not only upon the apple, but also 

 ujjon the pear and quince fruit. The author's experiments have shown that the fun- 

 gus causing the black rot and the canker fungus are identical. It is said that the 

 leaves of apple trees are occasionally attacked by a species of SphaTopsis the identity 

 of which is n(jt thoroughly established, but the indications are that it is the same as 

 that occurring upon the other parts of the tree. Inoculation experiments were con- 

 ducted to determine if possible the relationship between the different forms of Spha?- 

 ropsis occurring on various plants. Cultures were taken from cankered apple-tree 

 limV>s and from decaying apples, and inoculation experiments made upon apple, pear, 

 hawthorn, apricot, peach, sumac, i)ersimmon, and hop hornbeam. The inocula- 

 tions were successful only where applied to the apple, pear, and hawthorn, but 



