414 A Tomato Canker 



12. 2. 20. Dark green, water-soaked areas round needle pricks. 



16. 2. 20. Two tomatoes ripened and were removed from plant; tissue round 

 needle prick has remained green with a slight tendency to brown discolouration and 

 are crowded with bacteria. 



25. 2. 20. Remaining fruit ripened and picked. All calyces show numerous in- 

 fections, but fruit infections have not gone beyond the green, water-soaked stage. 

 Stems show extensive cankers where they were slightly injured by friction of beaker 

 placed over fruits after inoculation. Control plants remained sound and showed no 

 sign of infection. 



B. 



10. 3. 20. Three large tomato plants were used, bearing fruit at various stages of 

 development. Some fruits were left uninjured, others pricked or lightly scratched. 

 The culture was applied to fruits and leafy tips with a camel's hair brush, and the 

 plants atomised with water. The leaves were left uninjured. All inoculated portions 

 were covered for 24 hours with butter paper bags, to prevent excessive drying. 



13. 3. 20. Numerous minute light and dark brown specks on younger fruits. 



18. 3. 20. Numerous minute, water-soaked spots on leaves, also indications of 

 infection round needle pricks on fruit. 



23. 3. 20. Tomatoes which were very young when inoculated and which were 

 not pricked show minute brownish blisters all over the surface. One which had only 

 just set when inoculated had an irregular water-soaked zone round the blisters up 

 to 2 mm. diameter. Leaf infections increasing in size and number and assuming 

 characteristic purplish grey colour. Infected spots also visible on calyces, pedicels 

 and stems. 



29. 3. 20. Spots on small tomato mentioned above beginning to discolour: water- 

 soaked zone round blisters on slightly larger fruit and round needle pricks on fruit 

 which was inoculated by puncture when almost full grown. 



12. 4. 20. Scabs on all fruits now quite typical; they have discoloured, become 

 brown, epidermis has blistered and cracked in several directions. Badly infected 

 leaflets become entirely yellow and dead. 



13. 4. 20. Plants discarded. Control plants showed no sign of infection. 



c. 



29. 3. 20. Eight young plants about 1 ft. high were used. They were inoculated 

 by atomising with culture isolated from artificially infected plant described in 

 experiment B. 



6. 4. 20. Numerous minute, water-soaked areas observed on younger leaves. 



13. 4. 20. Leaf spots have assumed typical form and colour. Control plants 

 showed no sign of infection. 



D. 



10. 5. 20. One tomato plant in bearing was inoculated. Fruits of various sizes 

 and leafy tips were inoculated without wounding, and covered with butter paper 

 bags for 24 hours. 



19. 5. 20. Small raised spots visible on fruits, water-soaked spots on leaves. 

 (The majority of the affected fruits and leaves were removed for purpose of studying 

 morbid anatomy.) 



