i6o 



Bulletin 235. 



to include also the quince curculio, the rose chafer, and the grape root- 

 worm. Alany of the experiments were also continued during the past 

 year so that the results here recorded are often deduced from the experi- 

 ences of two seasons. 



I planned the experiments and in many cases visited the fruit-growers 

 and inspected their orchards both before and after spraying. The spray- 

 ing was done by the orchardists according to my directions as nearly as 

 was practicable, but in the case of the grape root-worm most of the work 

 was done by an expert student assistant. In all the experiments a poison- 

 ous insecticide known as arsenate of lead was used. Small quantities, 

 varying from 10 to 40 pounds, of this poison were furnished to the ex- 

 perimenters free of charge. In 1904, 650 pounds of the arsenate of lead 

 were purchased, 350 pounds being used in vineyards against the root-worm 



beetles. Six hundred 

 pounds were distrib- 

 uted during the past 

 season, half of which 

 was used against the 

 grape root-worm. 



While no new and 

 startling facts have re- 

 sulted from these co- 

 operativeexperiments, 

 they have often been 

 excellent object les- 

 sons for neighbor- 

 ing fruit-growers and 

 have served to bring 

 the experimenters in 

 touch with the Ex- 

 periment Station and 

 its methods. Each 

 experiment has been 

 a valuable teacher and 

 illustrator in its neighborhood, no matter what the final results. 



Fig. 40. — Mr. Wood's sprayed plum tree. Note how 

 lite branches bend ivilfi their weight of frtm. 



The Plum Ci'Rculio Experiments 



Spraying with a poison for the plum curculio is nut a new notion. 

 During the past thirty years there have been recorded many successes and 

 some failures in combating this enemy of stone fruits with a poisoned 

 spray. ]\Iany ])rominent fruit-growers feel sure that they can and do 

 control this pest with such a spray, while others are thoroughly wedded 



