THE POTATO. 131 



gypsum or calcium carbonate (ordinary lime) or clean wood- 

 ash, forming a crust over the surface. The object of this is to 

 prevent undue desiccation. Cut seed should be planted soon 

 after cutting, and should not be left exposed or planted in 

 dry ground. Experiments at Grootvlei and Tweespruit, 

 O.F.S. (1906-1908),' showed a marked increase of whole over- 

 cut tubers, when the same spacing was used in planting. 



Seed Tubers. — Where seed has been held dormant it is 

 good practice to place the seed in a light warm place to 

 sprout. This should be done some time before planting — a 

 uniform standard is obtained in this way, because potatoes of 

 retarded germination can be discarded, and only those planted 

 which have started to sprout. The shoots should not be 

 allowed to grow too long. 



The great di fficulty i p_^outh Africa at prese nt is to 

 procir yseecT ol Jl ie prope r maturity at the difFercnt times of 

 ^janfing, as it is almost impo ssible to secure_places of low 

 enough temperature to ensure~~<^CSTInant" tubers. Seed lifted 

 during the winter months start sprouting with the advent of 

 warm spring weather, and as this is not used for the main 

 crop until November and December, it is found 

 hard to retard the growth until then. With the prevailing 

 high temperatures of September and October this is by no 

 means easy of accomplishment. Some farmers are successful 

 in doing the lifting as late as possible, about the end of July 

 (in some places in October) and then placing them in mounds. 

 These mounds are made by having the tubers in long piles 

 covered with a thick layer of grass, which, in turn, is covered 

 with about a foot of soil, care being taken to chose a cool, 

 well-drained site, and to provide good ventilation by having 

 holes through the covering, which are usually kept fairly open 

 with bundles of grass. In this method the pile should be 

 examined from time to time to see that the tubers are not 

 decaying. 



In storage the temperature should be kept as low as 

 possible (in South Africa), the humidity of the air in the stor- 

 age place should not be high nor too dry, and the supply of 

 air (oxygen) should be limited. 



Where small amounts of seed are handled greening is 

 possiblv the best method. Here the tubers are placed one 

 layer thick in shallow crates, which are placed in a well-venti- 

 lated situation in strong light. In this manner they may be 

 kept sound for several months while they produce short. 



