106 



VEGETABLE GROWING PROJECTS 



5. Name some other maggots that affect cabbage. 

 CL:36. CL:37-38. 



6. How does the imported cabbage-werm adult differ rjrom the other 

 coTwmon cabbage butterflies f CL: 6-8. 



7. Can the caterpillar be easily distinguished? : CL : 5-8. | 



8. Describe briefly the life history of the imported ''cabbage worm} 



CL:4-5. I 



f '< 



9. Does it injure the outer leaves only f CL : 5. 



10. What is the best spray to use? CL : 6. ' 



11. What other common cabbage worms iiffed this crop? CL : 7-21. 



Black rot causes enormous losses to cruciferous crops bothi 



in the field and in storage. 

 This is a bacterial disease and 

 is first noticeable in the field 

 by a blackening of the veins 

 near the edges of the leaves. 

 Such leaves soon become yellow 

 and die. If infected plants 

 are stored, the disease con- 

 tinues to develop in storage. 

 The black rot bacteria live 

 in the soil and may be 

 spread upon the seed or on 

 plants shipped from one place 

 to another. They may also 

 be spread from field to field 

 on tools and in manure. Con- 

 trol measures invoh-e first of 

 all crop rotation. Cabbage should not be planted for several 

 successive years on soil which has produced cabbage with black 



Fig. 31. — Aphis-infested cabbage leaf . 



