1913.] PUBLIC DOCUMENT — No. 31. 175 



disulfid per acre, therefore, allowing the material to be pur- 

 chased at half what it actually cost for the experiments, would 

 be at least from $20 to $30 per acre, — a prohibitive expense. 

 Nicine. — This substance, manufactured by the Hood Chem- 

 ical Company of Chicago as a deodorant, disinfectant and germ- 

 icide, was offered for trial as an insect repellant. It is a 

 powder, and directions furnished by the company were as fol- 

 lows : — 



Where a plant or tree is infected ^Yith root maggots shake off as much 

 of the earth from the roots as possible. Then sprinlde nieine over the 

 roots and plant in fresh soil, and if convenient make a small circular 

 ditch about 3 or 4 inches deep around the jjlant and lY^ to 2 feet from 

 the center. Sprinkle nicine freely in this ditch, cover up with soil, and 

 the plants will not be bothered with maggots or insects. 



It was manifestly impossible to follow these directions in 

 the case at hand. The nicine was therefore dusted along the 

 rows, care being taken to place a good supply around the base 

 of each plant. As the maggot must work down along the plant 

 to the bulb, where it feeds, this method would seem to force the 

 maggots to pass through, or at least close to, the powder, which 

 has a very pronounced odor. 



The result of this experiment was unsatisfactory, as plants 

 in the rows treated became infested shortly after the applica- 

 tion. In fact, some of the earliest infestations in the field were 

 in rows treated in this way. 



At such prices as have been quoted for this material, enough 

 to treat an acre in this way would cost about $50, and the labor 

 in applying it would cost about $12 or $13. Evidently, then, 

 this material is not available for use on large onion fields, irre- 

 spective of its effectiveness, because of the expense which would 

 be incurred. 



Powdered Ilellehore. — Ordinary powdered hellebore was 

 dusted liberally along the rows around and over the bases of the 

 plants, with the idea that the young maggots working down to 

 the bulbs to feed would come in contact with it and be destroyed. 

 It has been supposed that it might also act to some extent as a 

 repellant, preventing egg laying. 



Results from this treatment could at best be rated as only 



