INJURIOUS TO CABBAGE AND CRUCIFEROUS CROPS 351 



that many of them will not succeed in finding the new plant- 

 ing. 



As the maggots infest wild mustard and various similar weeds, 

 they should be destroyed as far as possible and crops affected by 

 the maggots should not be planted on or near land badly infested 

 with such weeds if avoidable. Wild mustard may be readily killed 

 by spraying it while young with iron sulfate, 2 pounds to 1 

 gallon of water. 



Late-planted cabbage is 

 but slightly affected as com- 

 pared with that planted earlier. 

 The earliest radishes are often 

 quite free from the pest, those 

 planted later and maturing 

 just as the flies are abundant 

 are badly injured, and the later 

 plantings are free from injury. 

 It is evident, therefore, that 

 where planting of the main 

 crop can be delayed until after 

 most of the flies have ovi- 

 posited, that it will escape 

 serious injury. Furthermore, 

 either cabbage or 

 may be used as a trap crop, 



by planting a few rows early and as soon as the flies had laid 

 their eggson them, plowing them under deeply and then setting 

 the main crop. All of these methods involve a familiarity 

 with the fly and its eggs which any observant grower may 

 soon acquire. 



High fertilization with a quickly available fertilizer will enable 

 the plants to make a rapid growth and will be profitable even if 

 maggots do not occur. 



Thorough and frequent cultivation while the eggs are being 

 laid destroys many of them. Indeed, one of the best means 

 of control, which is extensively practiced by many growers, is to 





FIG. 252. Eggs of cabbage maggot at 

 radishes base of stalk. (Photo by Headlee.) 



