EXPERIMENT STATION BULLETINS. 



369 



toes in 1903 when no treatment for scab had been applied. Though this 

 ground has been plowed each year, the test would seem to indicate that 

 a longer time is necessary before it is safe to plant potatoes upon scab- 

 infested ground. 



The roAvs were 4 feet apart and one to five rows of each variety were 

 planted. As the plot is irregular in shape, the space occupied by each 

 variety is given in number of square feet and the yield is shown in the 

 following table: 



POTATOES ON MUCK SOIL. 



Muck, when well drained and not acid, is generally considered well 

 adapted to potatoes and more especially to high grade seed potatoes, 

 for the muck seems to have the ability to prevent the development of 

 scab and the tubers have a brighter and glossier appearance though 

 the yield is claimed to be less than from better grades of potato soils. 

 Since muck is the residue of organic matter slowly decomposed in the 

 presence of more than an ordinary amount of water, its presence im- 

 plies a level area in the vicinity of hills or higher ground from which 

 a portion of the vegetable matter has been carried down. As cold 

 air during frosty nights rolls down from the higher and accumulates 

 upon the lower and level ground below, it therefore implies as well 

 that potatoes on muck ground are more subject to damage from frost 

 than they are upon the higher ground. A greater immunity from un- 

 seasonable frosts is afforded by muck beds, such as those of the station 

 grounds which are rlose to a creek and about 35 feet above it, for a 

 large volume of cold air will rapidly follow the downward course of 

 the creek. 



In various portions of the Upper Peninsula there are extensive muck 

 beds, such as those near Newberry. More or less acidity may be ex- 

 pected in some of these. Others will be found nearly or entirely free 

 from acid, and this more especially applies to those within the extensive 

 region which comprises the Calciferoiis, Trenton and other limestone 

 formations, for these beds are underlaid with limestones and frequently 

 marl, the lime of which acts as a neutralizing agent. The muck bed of 

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