214 



SOUTUKHN FIELD CHOPS 



Fungous Diseases 



While the corn plant is subject to a few diseases, these 

 are not kno^wi to cause much injury in the South, with 

 the exception of those mentioned 

 below, which injure chiefly the ear. 

 195. Corn smut ( Ustikigo maij- 

 dis). — The presence of this disease 

 is first shown by a large swelling 

 on the ear, the stem, the tassel, or 

 the leaf (Fig. 108). At first, this 

 protruding mass is covered with a 

 whitish skin, which later biu'sts, 

 setting free clouds of lilack powder. 

 These powdery particles are the 

 spores, or bodies answering the 

 liur])ose of seed, and serving to 

 s]>read the ilisease to the next year's 

 crop. These s])ores gain entrance 

 to the young plant after it has 

 appeared al)ove ground. The spread of this disease is 

 due to smut masses left in the soil liy a preceding corn 

 crop, or l.)lown in l^y the wind from surrounding corn 

 fields. No treatment of the seed is effective. 



The method of s])read of the disease suggests tlie means 

 of decreasing it in sul)se()uent ci-ojis, liy gathering and 

 burning the smut masses before the wliitish skin breaks 

 and sets free the spores. On \\w same princiiile, rotation 

 of crops is ad\'isable, espei'ially if this results in growing 

 corn on land wlierc- no surrounding fields in the ])receding 

 year matured smut s])ores. 



Fig. 107. — The Indi.vn 

 Meal Moth. 

 The lan'ce injure corn 

 Enlarged. (Plioto by W 

 K. Hind*) 



