416 STATE BOARD OF AGRICULTURE. 



and the odor was still quite noticeable the next morning after the treat- 

 ment. From this it was concluded that the vapor had been passing up 

 through the soil and out into the air for a period of about eighteen hours. 

 Lettuce, tomato and cucumber })lants are among those most readily at- 

 tacked by the root-knot nematode; therefore, it was decided to use these 

 plants to determine whether or not the soil treatments had eradicated 

 the pest. May 14, 1913, lettuce seeds were planted in the carbon bi- 

 sulphide treated plot, and also in the untreated soil about the plot to 

 serve as a check on the treatment. May 31, 1913, the seeds planted May 

 14th had not produced many plants so the plot was replanted with let- 

 tuce, tomato and cucumber seeds. June 16, 1913, some of the larger 

 lettuce plants were dug from the plot and their roots found to be some- 

 what affected with nematodes as shown by the small knots on them. 

 Check plants dug from the soil outside of the plot were more seriously 

 affected than those from the treated plot, thus showing that the nema- 

 todes had been reduced in numbers, but not eradicated by this carbon 

 bisulphide treatment. 



June 30, 1913, the rest of the plants were dug from the treated soil 

 and the roots were found to be abundantly covered with knots, showing 

 tliat the nematodes were increasing in numbers in the treated soil. 

 August 10, 1913, this plot was retreated with carbon bisulphide as be- 

 fore, except that the surface of the soil was sprinkled with water and 

 covered with burlap sacks, after the treatment, in an effort to keep the 

 carbon bisulphide vapor from passing so rapidly from the soil out into 

 the air. August ISth the sacks were removed from the surface of the 

 plot and lettuce seed was planted in the treated soil. September 8th some 

 of the lettuce plants were dug and examined but no knots were found on 

 the roots. It was impossible to get further data on this plot during the 

 rest of the season. In the summer of 1914 the author examined lettuce 

 and cow pea j)lants from this plot and found nematodes on their roots. 



TOBACCO STEM TREATMENT. 



The second plot was treated with tobacco stems. A wagon load of 

 tobacco stems was collected from various cigar factories and taken to 

 the garden. May 12, 1913, a layer of these stems over six inches in thick- 

 ness was spread over all the soil of plot II. May 14, 1913, the stems were 

 wet down with water. May 31, 1913, the layer of tobacco stems was removed 

 from the plot and lettuce, tomato and cucumber seeds were planted in 

 the treated soil, and also in the untreated soil outside the plot. June 

 16th some of the plants were dug from the treated soil and examined 

 but no knots were found on the roots. June 30th lettuce, tomato and 

 cucumber plants were dug from the treated soil and examined but no 

 knots were found on their roots. August 11th, the author dug up lettuce, 

 tomato and cucumber plants from the treated soil and found some small 

 knots on their roots, showing that the nematodes had been reduced in 

 numbers for a time, but not eradicated. The writer does not feel that 

 such a treatment can be depended upon to give the desired results. 



