TILLAGE, PLANTING, AND CULTIVATION 



379 



After ploughing old maize lands, the stalks and roots lying chap. 

 in or near the surface should be gathered together by means IX - 



Fig. 135. — Zigzag harrow. (Courtesy of Messrs. Malcomess & Co.) 



of the harrow and burned in heaps to kill the stalk-borers 

 (" mest-worms ") which are hiding through the winter in the 

 hollow part of the base of the stem (cf. If 407). 



Fig. 136. — Riding cultivator. (Courtesy of Messrs. Malcomess & Co.) 



Cross ploughing or cross cultivation are useful methods 

 of treatment for closing up the air spaces by drawing together 



