30 MASS. EXPERIMENT STATION BULLETIN 339 



of those used (on July 1), struck root decidedly better in sand and peat moss 

 with these treatments than without them: Cytisus purpureus and Genista 

 tinctoria watered only with vinegar 8cc. diluted to 4000 cc. with water, and 

 Artemisia Abrotanum and Indigofera decora watered only with vinegar 16 cc. 

 similarly diluted. 



Cuttings of several species were allowed to stand for some hours with their 

 bases in solutions of indoleacetic acid or indolebutyric acid, following which 

 treatments they were inserted in sand. More species were unaffected than were 

 benefited, but the rooting of some was hastened and otherwise improved by the 

 treatments, as follows: 



Grams in 1 ,000 cc. of water 



Species Date Number of 



Indoleacetic Indolebutyric hours of 



acid acid treatment 



Abelia grandiflora Aug. 20 — 0.025 65 



Caryopteris incana. July 31 0.050 — 41 



Chamaecyparis sp Aug. 20 — 0.025 65 



Chamaecyparis pisifera var. plu- 



mosa Aug. 20 0.100 — 22 



Chamaecyparis pisifera var. squar- 



rosa Oct. 17 — 0.100 24 



Coronilla Emerus Oct. 17 0.100 — 23 



Corylopsis spicata Aug. 20 — 0.025 48 



Dorycnium hirsutum Oct. 16 — 0.100 22 



Lespedeza formosa Oct. 16 0.100 — 22 



Styrax Obassia July 31 0.025 65 



In some cases these treatments not only improved rooting, but also appar- 

 ently prolonged life of cuttings. Thus, when 36 percent of the treated cuttings 

 of Lespedeza formosa had rooted and 96 percent were living, only 50 percent of 

 the untreated cuttings of this species were living and none of them had then 

 struck root. 



These treatments are not inexpensive and it is important therefore to learn 

 not only for what species they are altogether unnecessary, but also for what 

 species they are most beneficial. In this work, and with some exceptions, the 

 cuttings most benefited were the softer wooded and those from which roots 

 develop along the whole length of the buried stem. 



Phenylacetic acid, as used, was without effect on the rooting of hardwood 

 cuttings. 



Rooting of cuttings was improved more by their treatment with indoleacetic 

 or indolebutyric acids than by the treatment of rooting media with potassium 

 permanganate, and the effect of the latter was not influenced by inoculation of 

 the medium. 



A severe disease of the above-ground parts of thyme, several varieties of 

 Thymus Serpyllum L., was observed in gardens. A strain of Rhizoctonia solani 

 was isolated and its pathogenicity established by inoculation. Infection is 

 common in rainy weather in early summer, and the otherwise attractive mats 

 made by this fine ground cover become unsightly. 



Diseases of Trees in Massachusetts. (M. A. McKenzie and A. Vincent 

 Osmun. ) Field and laboratory investigations to determine the occurrence and 

 significance of shade tree diseases in Massachusetts, initiated in the summer of 

 1935, were carried on during the past year. The principal objective of the 

 program was to determine whether the so-called Dutch elm disease, caused by 



