82 Repokt of the Botanist of the 



THE three years' EXPERIMENTS 1898-1900. 



Objects of the Experiments. 



In the experiments of 1897 the best results were obtained 

 ■where the smaller quantities of sulphur and lime, 125 and 250 

 pounds per acre, were used. This fact suggested the idea that 

 perhaps the larger quantities of the mixture were in some way 

 injm-ious to the growth of the plants. When the treatment is 

 applied every year for a series of years 'a considerable quantity 

 of the sulphur and lime must accumulate in the soil. Now the 

 question arose, What will be the effect of repeated applications 

 of sulphur and lime? If the accumulation of these substances 

 in the soil injures the growth of the plants perhaps it will be 

 better to use even smaller quantities than 125 pounds per acre. 

 On the other hand, if such accumulation in the soil is not detri- 

 mental to the plants, may we not expect better results with the 

 smut after the soil once becomes thoroughly impregnated with 

 the chemicals? Hence, one object of these experiments was to 

 determine the effect of repeated applications of the sulphur and 

 lime. 



The application of sulphur and lime in the row involves con- 

 eiderable extra labor. Why not save this labor by applying the 

 mixture broadcast? Hence, a second object of these experiments 

 was to determine the effect of broadcast applications of sulphur 

 and lime. 



For convenience we will hereafter call the experiments in 

 which the chemicals were applied in drills Series I, and the ex- 

 periments in which they were applied broadcast Series II. 



Series I. — 'Sulphur and Lime in Drills. 



Plan of experiments. — In the work of the previous two years 

 we learned that onion smut is rarely equally destructive to all 

 parts of a field. Often there are great differences in a distance 

 of a few feet. In order to eliminate from an experiment the 

 effect of such inequalities in the soil the plats must be long and 

 narrow and duplicated several times. But since it was planned 

 to continue the experiments for three years the plats must be 



