226 . 



T. tritivi) in continuation of those reported in Bulletin Xo, 12 of the 

 .station (see E\|mi iinciit Station Keeord, vol. ii, p. I'L'O). Keleienee is 

 also made to experiments on oat smut, reported in Bulletins 2s'os. 8 and 

 15 and the Annual Eeport of the station for 1889 (see Experiment Station 

 lieeord, vol. i, p. 216, and vol. ir, pp. 340 and 638). The bulletin is illus- 

 trated with a plate showiuf;- smutted and sound heads of wheat. The 

 land used for the exi)eriments reported in this bulletin was upland soil 

 used the previous season in experiments on oat smut. 



The seed used was artificially smutted. It was jilafed in a box and a lar;^e (jnan- 

 tity of more or less broken smutted grain added, and the whole was thoroughly 

 stirred with hoe and shovel till the grains were black with smut. Without furtlier 

 preparation this was used for the alternate untreated plats. » * * nie variation 

 in amount of smut on these plats was enormous, and the rca.son for it is not fully 

 known; yet the fa«'t that all the untreated plats were ))lanted with the drill suc- 

 cessively may account for at least some of the variatiiui, since the smutted grains 

 are of much less specific gravity than the sound ones, and would be sown in greater 

 abundance the maror the seed box was emjity. 



Ditfereut methods for treating the smut were tried uii •.•:; plats, each 

 ('((iitaiiiing 0.04 of an acre; the alternate plats rciimiiicd untreated. 

 Bordeaux mixture, can celeste, coit])or sulphate, <-(»]»jM'r acetate, cojtjjer 

 nitrate, coppin' chloiide, nuircnric chloride, potassium bichronmte. and 

 " Ward's Seed Manure" were used in different forms and applied. \\ ith 

 one exception, during 24 hours. Tlot water at tem]>eratures varying 

 IVom 138^ to 127^ F. was also used, the seed being dipped from ."> !<» ]."i 

 minutes, and cooled in water at ordinary .summer t/emperature, in an 

 ice-salt mixture or in I0i)er cent CuSO^ solution. The results as indi- 

 indicated l)v the yields of smutted an<l sound grain on both the treated 

 an<l untreatcfl |>lals, are stated in a table, and those on a number of 

 j)lats are illustrated by diagrams. The following treatments destroyed 

 all the smut and gave a yiehl of grain greater than the average of 

 the two adjacent untreated ])lats: ('o])i)er suljihate 0.5, or 1 per cent 

 .solution, 24 hours, or 0.5 per cent solution 12 hours, limed; copper 

 acetate 0.5 per cent solution, 24 hours; co]»per nitrate 0.5 i)er cent solu- 

 tion, 24 hours: hot water 137°, 136°, or 131° F., 5 minutes, cooled in 

 water of ordinary summer temperature; 136°, 135°, or 128° F., 10 min- 

 utes, cooled; 129° F., 15 minutes, cooled; 130°, 129°, 128°, or 127°F., 10 

 minutes, cooled in 10 per cent .solution CuSO,. In a considerable number 

 of cases the yield on the treated ])lats was much greater than would 

 be expected by merely replacing the smutted heads by .sound ones. 

 Whether this extra increase is due to an increase in the percentage of 

 seeds germinating or to an increased vigor of the plants from the 

 treated seed, has not been determined. 



In general the results of the experiments reported in this bulletin 

 confirm the conclusions drawn from previous experiments. 



The .stinking smut of wheat is efl'ectually prevented by treating the eee<i with 

 water at a temperature of 1.^1° F.. \r> minutes. For cheapne.<»s as well sis for 

 gi rater efficiency (without injury to seed), this is recommended over all other 



