Apr. i-sept. IS. 1921 Illustrations XI 



Practical Universauty ok Field Heterogeneity as a Factor Influ- 

 encing Plot Yields 



Text Figures 



Page 



1. Montgomery's diagram of 5.5 by 5.5 foot plots of Turkey wheat, showing 



variations in the percentage of nitrogen in the grain 283 



2. Diagram showing yield of alfalfa in first cutting, 19 13, on the Huntley ex- 



perimental tract 286 



3. Diagram showing yield of alfalfa in second cutting, 19 13, on the Huntley 



experimental tract 287 



4. Diagram showing yield of alfalfa in first cutting, 1914, on the Huntley ex- 



perimental tract 288 



5. Diagram showing yield of alfalfa in second cutting, 19 14, on the Htmtley ex- 



perimental tract 289 



6. Diagram showing yield of alfalfa in third cutting, 1914, on the Htmtley ex- 



perimental tract 290 



7. Diagram showing yield of unhusked rice in Coombs and Grantham's 54 plots 



j4hy yi chain square 296 



8. Diagram showing yield of ear com, 19 15, on the Huntley experimental tract . 297 



9. Diagramshowingyieldof ear com, 19 16, on the Huntley experimental tract. 298 

 10. Diagram showing location of sample areas examined for soil moisture in a 



field at San Antonio Experimental Farm 302 



Transmission of the Mosaic Disease gb Irish Potatoes 

 Plates 



49. Vines of Green Mountain variety inoculated with juice from healthy foliage 



of the same variety 338 



50. Vines of Bliss Triumph variety inoculated with juice from healthy foliage 



of Irish Cobbler variety 338 



51. Vines of Irish Cobbler variety inoculated with juice from healthy foliage 



of the same variety 338 



52. Vines of Green Mountain variety inoculated with juice from mosaic foilage 



of the same variety 338 



53. Vines of Green Mountain variety inoculated with juice from mosaic foilage 



of Bliss Triumph variety 338 



54. Vines of Green Moimtain variety inoculated with juice from mosaic foliage 



of Irish Cobbler variety 338 



55. Vines of Bliss Triumph variety inoculated with juice from mosaic foliage 



of Irish Cobbler variety 338 



56. Vines of Irish Cobbler variety inoculated with juice from mosaic foliage 



of the same variety showing bad stage of mosaic 338 



Relative Susceptibility to Citrus-Canker of Different Species and 

 Hybrids of the Genus Citrus, Including the Wild Relatives 



Plates 



57. Leaf of Casimiroa edulis with naturally occurring spots from the greenhouse 



inoculations 362 



58. Infected leaves fi'om plants of Chaetospermum glutinosum in the greenhouse 



experiments, showing the types of canker spots produced 362 



