. Hawaii Agricultural Experiment Station, 



HONOLULU. 



E. V. WILCOX, Special Agent in Charge. 

 PRESS BULLETIN NO. 30. 



Killing Weeds With Arsenite of Soda 



BY 



E. V. WILCOX, 



SPECIAL AGENT IN CHARGE 



INTRODUCTION. 



Weeds and pests of insect or fungus nature are naturally 

 among the important problems with which the farmer has to 

 contend in all agricultural regions. In controlling these draw- 

 backs to successful production, hand methods were first used 

 but the use of chemicals was early adopted in combating insect 

 and fungus disease. Somewhat later, sprays for the destruction 

 of weeds received attention and chemicals for weed destruction 

 have gradually assumed a greater importance. Many of the 

 facts which are now known regarding the destruction of weeds 

 by means of chemicals were first discovered in connection with 

 spraying for insects and fungus diseases. In order to destroy 

 insects and pathogenic fungi by applications of chemicals to liv- 

 ing plants it is necessary to use solutions or mixtures of a 

 strength sufficient to be fatal to the insects and fungi but not 

 injurious to the plants which are to be protected. In the exten- 

 sive and long-continued spraying experiments which have been 

 carried on in farm practice, it was soon found that certain forms 

 of chemicals used in such operations were more injurious to 



