XV. 



MAIZE. 



WEEDS, FUNGOUS DISEASES AND INSECT ENEMIES. 



316. Weeds. — Maize differs from the other cereals in that 

 the grain as it goes to market does not contain weed seeds, nor 

 is there any danger of adding such seeds to the soil when the 

 maize is planted. There are, therefore, no distinctive weeds of 

 the maize crop, but weeds that chance to infest the soil may 

 occur in the maize field. Fields are not infrequently cultivated 

 in order that the cultivation incident to the maize may partially 

 or wholly eradicate existing weeds. This, in fact, is one of the 

 purposes of a systematic rotation of crops. Besides the injury 

 that all weeds do, some are more troublesome than others, either 

 through their tenacity, their immediate injury to the young maize 

 plant, or through the inconvenience which their presence in- 

 volves. Among the more troublesome weeds of the maize field 

 may be mentioned : 



(1) Foxti\l(.C/iamoera//its) . 



(2) Bindweed {Convolvtdits). 



(3) Cocklebur {Xanthmm cafutdense Mill., and A*, spinosum L.). 



(4) Spanish Needles {Bidens bipinnata L., B.connaia Muhl., and B.froiidosa L.). 



317. Foxtail. — There are two species of foxtail; one known as Pigeon 

 grass {Chamoeraphis glauca (L.) Kuntze), and the other known as Bottle grass 

 {Chamoeraphis viridis (L.) Porter). So far as actually reducing the yield of grain is 

 concerned, these foxtails are probably the worst weeds that infest the maize fields. 

 They are annuals, varying from a few inches to two feet or more in height, with 

 dense spiked Ireads, yellow in Pigeon grass and green in Bottle grass. The heads 

 are less dense and the bristles longer in the latter. Their abundance of seed, pro- 

 duced almost under any environment, which is evidently stored in the soil for con- 

 siderable periods, makes it almost, if not quite impossible, to eradicate it 

 permanently. 



318. BiNDV/EED. — There are a number of species belonging to the Morning 

 Glory family which may infest cultivated fields; the most serious are the field 



