46 STATE POMOLOGICAL SOCIETY. 



to the leaf by the calcium suli)hitle or other inert ingredient and 

 by the arsenate of lead. As soon as these facts became evi- 

 dent, trials were made of the fivngicidal value of finely ground 

 sulphur in preventing the spores of the apple scab fungus from 

 germinating. As was to have been expected, finely ground sul- 

 phur proved equally as effective as lime-sulphur solution. It 

 seemed, therefore, that the only question needing consideration 

 was to determine whether sulphur applied directly to foliage 

 and fruit of the apple could be depended upon to adhere for a 

 sufficient period of time to prove of value. If this proved to 

 be the case there seemed to be no reason why the fungicide 

 might not be applied in the dry state. It is well known that a 

 much larger area can be covered with a dusting outfit and that 

 orchards in which the soil is too wet to be sprayed with the 

 ordinary liquid sprayer might be covered satisfactorily with 

 such an apparatus. Work was started in the summer of 191 1 

 tp determine whether the dlisting method would prove effec- 

 tive or not. A dusting machine was obtained and dust m*ix- 

 tures of various sorts carrying various amounts of insect poison 

 ir addition to sulphur were applied. It was realized from the 

 outset that the satisfactory control of insect pests by means 

 of a dry poison was equally as important as the control of 

 apple scab with a dry fungicide, inasmuch as the two opera- 

 tions must be combined if for no other reason than the item of 

 cost. Owing to the very unusual season no results were ob- 

 tained in 191 1. In 1912 the work was continued, but not on a 

 very extensive scale, owing to the fact that orcnards could not 

 be found in which a reasonable amount of scab might be ex- 

 pected to develop. With the rather late fall rains of 1912, 

 however, scab spread abundantly on the foliage and accordingly 

 extensive experiments were planned for 1913. 



DUSTING COMPARED WITH SPRAYING. 



Two orchards were selected for the work and in each case 

 100 trees or more were included in the experiment. I exhibit 

 here a chart showing the results obtained in a Greening or- 

 chard at North Rose, N. Y. 



