XII Journal of Agricultural Research voi. xix 



Page 



59. A. — Leaves of Atalantia citrioides and A. ceylonica (center) from plants in 



the greenhouse experiments, showing the canker spots typically produced 

 on these plants. B. — Compound leaf of Hesperthusa crenulata from 

 isolation field, with naturally occurring canker spots on two of the leaves. 

 C. — Leaves of Microcitrus Garrowayi from plants in the greenhouse 

 experiments, with different types of canker spots. D, E. — Infected 

 leaves and twigs of Eremocitrus glauca from greenhouse plants, showing 

 the large flat spots on the leaves and the rather corky spots on the twig 

 and thorn 362 



60. A. — Typically infected leaf of Fortunella margarita. B. — Old leaf of Citrus 



grandis, with raised, compact, oily, unruptured spots. C. — Fortunella 

 Hindsii, with ruptured corky spots. D. — Citrus sp., Kansu of Yuzu 

 Orange. E. — Citrus aurantifolia, showing typical infection 36a 



61. Upper and lower leaf surfaces of a Citrus hystrix leaf with a heavy natural 



canker infection 36a 



62. Typically infected leaves of Citrus grandis from field plants showing ex- 



treme susceptibility 36a 



63. A. — Leaves and twigs of faustrime from greenhouse experiment with typical 



spots. B. — Types of spots foxmd on Citrus nobilis (King of Siam, Naran- 

 jita, and tangerine). C. — Leaf of tlie citrangequat from greenhouse ex- 

 periment. D. — Citrumelo leaf with typical canker spots. E. — Upper 

 and lower surface of a naturally infected leaf of Citrus mitis in the field . . 36a 



64. Naturally infected leaves of Citrus nobilis var. unshiu from the field, show- 



ing various types of spots produced 36a 



65. Some of the hybrids of Porcirus trifoliata, showing vigor, type of growth, 



leaf characters, and relative susceptibility to citrus-canker, arranged in 

 order of their susceptibility 36a 



66. A. — Limelos in the greenhouse inoculation experiments, showing type of 



growth, leaf characters, and susceptibility to citrus-canker. B. — Lime- 

 quats in the greenhouse inoculation experiments, showing type of 

 growth, character of leaves, and susceptibility to citrus-canker 36a 



67. A. — Siamelos in the greenhouse inoculation experiments, showing type of 



growth, leaf characters, and susceptibility to citrus-canker. B. — Com- 

 parison of type of growth, leaf characters, and susceptibility to citrus- 

 canker in clemelo, satsumelo, and tangelo in the greenhouse inoculation 

 experiments 3^3 



68. A. — Results of the greenhouse inoculations with some of the false hybrids. 



B. — ^Tangelos in the greenhouse inoculation experiments, showing type 



of growth, leaf character, and susceptibility to citrus-canker 36a 



Presoak Method of Seed Treatment: A Means of Preventing Seed 

 Injury Due to Chemical Disinfectants and of Increasing Germi- 

 cidal Efficiency 



Text Figures 



1. Graph showing effect of formalin i to 400 treatments with and without pre- 



soaking 37° 



2. Graph showing effect of formalin i to 200 treatments with and without pre- 



soaking 37* 



3. Graph showing effect of formalin i to 320, with and without presoaking 374 



4. Graph showing effect of copper sulphate i to 80, with and witliout presoaking, 



on wheat and barley seed germination 375 



5. Graph showing effect of formalin i to 320, with and without presoaking, on 



wheat seed germination under field conditions 377 



