Planting 143 



the later tillage of the crop with the rush period of 

 haying and harvesting. But increasing competition of 

 the southern crop is forcing many growers to abandon the 

 previously profitable early crop for local trade. Bordeaux 

 spraying has been found to lengthen the life of the potato, 

 and potatoes to be sprayed may be planted slightly earlier 

 than those unsprayed, for that reason. 



The methods of ridging and level culture with deep 

 and shallow planting are best illustrated by their use in 

 two of the best-known potato-growing regions of the 

 United States. Ridge culture with comparative shallow 

 planting is used in Maine. The northern latitude of 

 Maine makes the growing season short compared with 

 the southern states. The mean temperature of the 

 month of July is only 62° to 65° F. Frosts are frequent 

 in June and September and may occur in August. Not 

 much field work can be done before the month of May, 

 and October 10th is regarded as the danger line beyond 

 which potatoes are likely to be frozen in the ground. 

 Only a short distance away in the Atlantic Ocean, the 

 cold ocean current from the Arctic reaches the warm Gulf 

 Stream. The fogs of the fishing banks here are well 

 known. The rainfall is heavy and is seldom deficient 

 throughout the growing season. The rainfall of winter 

 is largely available to the potato crop. The ground is 

 covered with snow all winter and the loss by run-off and 

 evaporation before time of planting is much less than 

 that of the other great producing states. The soil con- 

 ditions of Aroostook County, the great potato-producing 

 section of Maine, are favorable for the retention of soil 

 water. Most of that section has been cleared from the 

 forests only a few years, compared with the longer settled 

 comcmunities, and the soil is well supplied with organic 



