MANAGEMENT OF THE GROWING CROP 107 



difficulty is experienced in securing machinery which 

 will dig all the tubers. 



Level Culture. In this system the potatoes must be 

 planted a little deeper than in the case of the other 

 two, to reduce the percentage of sun-burned tubers. 

 This system is advocated throughout most of Eastern 

 North America, as, among other things, the quality of 



FIG. 30 HALI.ECK EXPANSIBLE WEFDER 



the potatoes is better, owing to the ground being 

 cooler. Its use has been found advisable at such 

 various points as Cornell, 1 Louisiana, 2 North Caro- 

 lina, 3 Wisconsin, 4 and Arkansas 6 Experiment Stations, 

 while the Maryland 8 Station, in a trial lasting six years, 

 found little difference between level and drill culture, 

 but the slight variation was in favor of level culture. 



Method of Cultivation and Tools Used. About 

 a week after planting the spike-tooth harrow should 

 be run over the land, preferably in both directions, if 

 a mulch is not made by one harrowing. This destroys 



1 (N. Y.) Cornell Bui. 140, p. 390; 156, p. 175. 2 I<a. Bui. 22, p. 705. 



a N. Car. Bui. 85, p. 4; 146, p. 262. * Wis. Report, 1899, p. 210. 



* Ark. Bui. 50, p. 29. Md. Bui. 62, p. 204. 



