junei. I920 Behavior of the Citrus-Canker Organism in the Soil 197 



Thus inoculations were made each day from 10 infusions of soil. 

 These 10 infusions were identical in every way except that 5 were made 

 from a flat of soil which had been inoculated with P. citri after being steri- 

 lized while the other 5 were made from a flat of soil which had been inocu- 

 lated without being sterilized. Tables V and VI give the results of the 

 inoculations. 



Table V. — Inoculation of young pummelo leaves from infusions of untreated soil in a 

 box made on consecutive days after inoculation u'itk P. citri. The inoculated soil was 

 placed in the orchard to simulate field conditions 



Leaves No. 



I to 5 



6 to 10 



II to IS 



16 to 20 



21 to 25 



26 to 30 

 31 to 35 

 36 to 40 

 41 to 45 

 46 to 50 



51 to 55 

 56 to 60 

 61 to 65 

 66 to 70 

 71 to 75 



76 to 80 

 81 to 85 

 86 to go 

 91 to 95 

 96 to 100 



loi to 105 

 106 to no 

 III to 115 

 116 to 120 



121 to 125 

 I2& to 150 



131 to 135 

 136 to 140 

 141 to 145 

 146 to 150 



151 to 155 

 156 to 160 

 161 to 165 

 166 to 170 



171 to 175 



176 to 180° 

 181 to 185 

 186 to 190 

 191 to 195 

 196 to 200 



Infusion 

 tube No. 



Number 

 of days 

 1 after inoc- 

 ulation 

 into soil. 



16 



17 

 18 



19 



20 



23 

 24 



25 



27 

 28 



29 



32 

 '62, 

 34 

 35 



36 



37 

 38 



39 

 40 



Date of inoculation 

 on leaves. 



10 

 10 

 10 



Oct. 23, 1918 



do 



do 



do 



do 



Oct. 24, 1918 



do 



do 



do 



do 



Oct. 25, 1918 



do 



do 



do 



do 



Oct. 26, 1918 



do 



do 



do 



do 



Oct. 28, 1918 



...do 



do 



do 



do 



Oct. 30, 1918 



....do 



... .do 



do 



do 



Nov. I, 191J 



do 



do 



do 



do 



Nov. 3, 1918 

 ....do 



do 



do 



Infections from 200 

 punctures. 



77 per cent positive. . 

 80 per cent positive . . . 

 87 per cent positive . . 

 100 per cent positive. 

 53X P^r cent positive . 



22 per cent positive. . 

 28 per cent positive. . 

 54^2 per cent positive. 

 7SK per cent positive . 

 73 per cent positive . . 



16K per cent positive . 

 8K per cent positive . . 

 18J2 percent positive. 

 i~,yi per cent positive . 

 2 1 per cent positive . . 



All negative 



do 



I K per cent positive . 



All negative 



6 per cent positive . . . 



AH negative 



do 



do 



do 



do 



.do. 

 .do. 

 .do. 

 .do. 

 .do. 



.do. 

 .do. 

 .do. 

 .do. 

 .do. 



All negative. 



....do 



... .do 



....do 



Date of 

 observation. 



Nov. 



2, 191J 



Do. 

 Do. 

 Do. 



Do. 



Nov. 4, igii. 

 Do. 

 Do. 

 Do. 

 Do. 



Do. 

 Do. 

 Do. 

 Do. 

 Do. 



Nov. 5, 191^ 

 Do. 

 Do. 

 Do. 

 Do. 



Nov. 9, 191J 

 Do. 

 Do. 

 Do. 

 Do. 



Nov. 20, igii 

 Do. 

 Do. 

 Do. 

 Do. 



Do. 

 Do. 

 Do. 

 Do. 

 Do. 



Nov. 20, 1918. 

 Do. 

 Do. 

 Do. 



a Leaves 176 to 180 were inoculated and then found to be already naturally infected at insect injuries. 

 These leaves were therefore cut off Nov. 3, 1918, and were not carried in the experiment. 



