Vegetable Growing for Market 



chats than whole sets; but it was observed that the size of saleable 

 potatoes was larger from the cut sets." 



Earthing" up and Sunshine. Another point in potato culture inti- 

 mately associated with the distance given between the rows and sets is 

 the question of earthing up, and the direction. In experiments carried 

 out with " Hyatt's Early Ashleaf " it was shown that a greater yield, 

 fewer chats, and better samples were obtained from sets planted 3 ft. 

 apart every way than from 2 ft. apart. To see whether there was any 

 difference between moulding up the rows north and south and rows 

 east and west another experiment was carried out under identical con- 

 ditions. The sets were 3 ft. apart every way, the only difference being 

 that in one case the earth was drawn up in ridges running north and 

 south, and in the other east and west, with the following results: 



EARTHING UP "NORTH AND SOUTH" VERSUS "EAST AND WEST" 



From this it will be seen that such an operation as earthing up may 

 mean a profit or loss to the grower according to the way it is done. 

 Although the sets were 3 ft. apart every way, the fact that the rows 

 were moulded up east and west instead of north and south meant a loss 

 at the rate of 2 tons to the acre, and a worse sample into the bargain. 

 The reason of course is quite plain. By earthing up north and south 

 the rows are fully exposed on both sides to the sunshine at midday, 

 when the work of assimilating carbonic acid gas from the atmosphere 

 is going on rapidly to make tissue and tubers. The soil is also warmed 

 on both sides, and providing it contains sufficient moisture and soluble 

 food the best results may be anticipated. By earthing the rows up 

 east and west, however, the grower is distinctly taking money out of 

 his own pocket, as the experiment shows. At midday only one side 

 the south of the rows catches the sunshine, while the other side the 

 north is in perpetual shade. Not only is this the fact, but all rows 

 after the first one may be said to be more or less deeply shaded on the 

 south side also. Hence but very little warmth from the sun reaches the 

 soil, and, the genial warmth so essential to growth being lacking, the 

 root action is poor in consequence, and less food is taken up to the 

 leaf cells to be acted upon by the light. 



The Dutch scientist Jan van Ingenhousz, who published his researches 

 in 1779, was the first to discover that all green -leaved plants fed upon 

 the carbon in the air during the daytime by means of the millions of 

 minute pores or stomata on their leaves; but very few r practical growers 



