INSECTS AND DISEASES 99 



although onion land is usually kept so clean that it 

 cannot be burned over in the fall, this practice will 

 be found very advantageous when it is possible. 



At the second and subsequent hand weedings all 

 onions which show smut in the second or third leaf 

 should be pulled, collected in a basket or other con- 

 venient receptacle and burned at once. This practice 

 involves very little trouble, and the folly of leaving 

 the larger smutted onions to discharge crop after crop 

 of spores upon the ground, as the leaves successively 

 mature, is apparent ; especially when the enormous 

 number of spores thus formed is considered. It is 

 hardly an overestimate to say that a single large onion 

 may mature during a season something like a cubic 

 inch of smut, which means between one and two thou- 

 sand millions of spores, each capable of producing a 

 smutty onion in the following season. 



If an onion grower has unlimited land suitable 

 for the crop it is almost superfluous to say that the 

 best means of avoiding smut is to take up new land 

 as soon as the old shows signs of the disease to any 

 considerable extent; but, as has been previously re- 

 marked, this is not a remedy for smut, any more than 

 it would be a remedy to stop raising onions altogether 

 in affected sections. 



Transplanting, as a Preventive of Smut upon 

 Onions — Two methods of raising onions have long 

 been practiced by Connecticvit growers ; one directly 

 from seed, the other from small onions of the previous 

 year's growth, called "sets." ... It has been 

 observed that onions raised from sets remain free from 

 the disease even upon fields where onions Raised 

 from seed always suffer more or less seriously. 

 Thaxter first . . . demonstrated that the smut 

 fungus enters the onion seedling only while the latter 

 is beneath the surface of the ground. . . . The fact 



