56 BUSH-FRUITS 



as they grow older, such as disease, reduced fertil- 

 ity of the soil, over -crowding, etc., that it is almost 

 impossible for them to yield a good return after 

 having borne two or three crops. Especially are the 

 various diseases which affect cultivated crops coming 

 to be such an important factor that it is necessary 

 to adopt every feasible precaution to prevent their 

 ravages. Not only .are the older plantations likely to 

 become diseased so as to greatly lessen their own pro- 

 ductiveness, but at the same time they become most 

 effective breeding grounds for the spread of these dis- 

 eases, and injurious insects as well, to new and 

 healthier fields. 



Moreover, the continuous production of suckers is 

 likely to fill the rows or hills so full of plants in a few 

 years that they are of necessity small and weak unless 

 vigorously thinned out. Even that does not fully over- 

 come the difficulty. The rows are almost sure to be- 

 come filled with weeds, and grass as well, and cannot 

 be kept clean without too great expense. It is on the 

 whole, therefore, bette,- to get three or four good crops, 

 then plow up the field and depend upon another plan- 

 tation ready for the purpose. The fruit will be larger, 

 hence more marketable, and the results more satisfac- 

 tory in every way. 



Although persistent, it is not very difficult to rid a 

 field of the plants by the same treatment recommended 

 for the blackberry. They may continue to appear for 

 some time, but they are not so strong but that they may 

 be easily controlled in whatever way the land is used 

 afterward. 



